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Scrolling to the bottom of page with invisible scrollbars [duplicate]

I have a panel1 with AutoScroll = true.I have to make panel1 scroll with btnUp and btnDown. So far I've made what I was asked for
private void btnUpClicked(Object sender, EventArgs e)
{
if (panel1.VerticalScroll.Value - 55 > 0)
panel1.VerticalScroll.Value -= 55;
else panel1.VerticalScroll.Value = 0;
}
private void btnDownClicked(Object sender, EventArgs e)
{
panel1.VerticalScroll.Value += 55;
}
But now I need to hide Scrollbar or make it invisible. I tried
panel1.VerticalScroll.Visible = false;
but it doesn't work. Any ideas guys?

Ok, I've done the working example of this for you. All you have to do is to change the max value depending on the total size of all the items inside your panel.
Form code:
public partial class Form1 : Form
{
private int location = 0;
public Form1()
{
InitializeComponent();
// Set position on top of your panel
pnlPanel.AutoScrollPosition = new Point(0, 0);
// Set maximum position of your panel beyond the point your panel items reach.
// You'll have to change this size depending on the total size of items for your case.
pnlPanel.VerticalScroll.Maximum = 280;
}
private void btnUp_Click(object sender, EventArgs e)
{
if (location - 20 > 0)
{
location -= 20;
pnlPanel.VerticalScroll.Value = location;
}
else
{
// If scroll position is below 0 set the position to 0 (MIN)
location = 0;
pnlPanel.AutoScrollPosition = new Point(0, location);
}
}
private void btnDown_Click(object sender, EventArgs e)
{
if (location + 20 < pnlPanel.VerticalScroll.Maximum)
{
location += 20;
pnlPanel.VerticalScroll.Value = location;
}
else
{
// If scroll position is above 280 set the position to 280 (MAX)
location = pnlPanel.VerticalScroll.Maximum;
pnlPanel.AutoScrollPosition = new Point(0, location);
}
}
}
Picture example:
You have to set AutoScroll option to False on your panel. I hope you understand what I've done and will get your panel running the way you want. Feel free to ask if you have any questions.

The Panel control takes on the duty you gave it by setting AutoScroll to true pretty serious. This always includes displaying the scrollbar gadget if it is necessary. So what you tried cannot work, hiding the vertical scrollbar forces Panel to recalculate layout since doing so altered the client area. It will of course discover that the scrollbar is required and promptly make it visible again.
The code that does this, Panel inherits it from ScrollableControl, is internal and cannot be overridden. This was intentional.
So using AutoScroll isn't going to get you anywhere. As an alternative, do keep in mind what you really want to accomplish. You simply want to move controls up and down. Easy to do, just change their Location property. That in turn is easiest to do if you put the controls on another panel, big enough to contain them. Set its AutoSize property to True. And implement you buttons' Click event handlers by simply changing that panel's Location property:
private const int ScrollIncrement = 10;
private void ScrollUpButton_Click(object sender, EventArgs e) {
int limit = 0;
panel2.Location = new Point(0,
Math.Min(limit, panel2.Location.Y + ScrollIncrement));
}
private void ScrollDownButton_Click(object sender, EventArgs e) {
int limit = panel1.ClientSize.Height - panel2.Height;
panel2.Location = new Point(0,
Math.Max(limit, panel2.Location.Y - ScrollIncrement));
}
Where panel1 is the outer panel and panel2 is the inner one that contains the controls. Be careful when you use the designer to put controls on it, it has a knack for giving them the wrong Parent. Be sure to use the View + Other Windows + Document Layout helper window so you can see this going wrong. After you filled it, set its AutoSizeMode property to GrowAndShrink so it snaps to its minimum size.

Try this:
panel.AutoScroll = true;
panel.VerticalScroll.Enabled = false;
panel.VerticalScroll.Visible = false;
Edit:
Actually when AutoScroll = true; It will take care of hscroll and vscroll automatically and you wont be able to change it. I found this on Panel.AutoScroll Property on MSDN
AutoScroll maintains the visibility of the scrollbars automatically. Therefore, setting the HScroll or VScroll property to true has no effect when AutoScroll is enabled.
You may try this to workaround this problem, I have copied it from this Link.
Behavior Observations 1:
If AutoScroll is set to true, you can't modify anything in VerticalScroll or HorizontalScroll. AutoScroll means AutoScroll; the control decides when scrollbars are visible, what the min/max is, etc. and you can't change a thing.
So if you want to customize the scrolling (e.g. hide scrollbars), you must set AutoScroll to false.
Looking at the source code for the ScrollableControl with Lutz Roeder's .NET Reflecter, you can see that if AutoScroll is set to true, it ignores your attempts to change property values within the VerticalScroll or HorizontalScroll properties such as MinValue, MaxValue, Visible etc.
Behavior Observations 2:
With AutoScroll set to false, you can change VerticalScroll.Minimum, VerticalScroll.Maximum, VerticalScroll.Visible values.
However, you cannot change VerticalScroll.Value!!! Wtf! If you set it to a non-zero value, it resets itself to zero.
Instead, you must set AutoScrollPosition = new Point( 0, desired_vertical_scroll_value );
And finally, SURPRISE, when you assign positive values, it flips them to negative values, so if you check AutoScrollPosition.X, it will be negative! Assign it positive, it comes back negative.
So yeah, if you want custom scrolling, set AutoScroll to false. Then set the VerticalScroll and HorizontalScroll properties (except Value). Then to change the scroll value, you need to set AutoScrollPosition, even though you aren't using auto scrolling! Finally, when you set the AutoScrollPosition, it will take on the opposite (i.e. negative) value that you assign to it, so if you want to retrieve the current AutoScrollPosition later, for example if you want to offset the scroll value by dragging the mouse to pan, then you need to remember to negate the value returned by AutoScrollPosition before reassigning it to AutoScrollPosition with some offset. WOW. Wtf.
One other thing, if you are trying to pan with the mouse, use the values of Cursor.Position rather than any mouse locations returned by the mouse events parameters. Scrolling the control will cause the event parameter values to be offset as well, which will cause it to start firing mouse move events complete with undesired values. Just use Cursor.Position, because it will use mouse screen coordinates as a fixed frame of reference, which is what you want when you're trying to pan/offset the scroll value.

Drag and Drop custom controls between cells in a grid in WPF

I've got some custom controls which are dynamically added to a custom grid. These controls can span over several columns and rows(which are all the same size). I'd like to drag and drop between the rows and columns. I can drag the individual controls, but they can move anywhere without limit. Even off the grid. I'd like to do it so it can only be dragged inside the grid AND snaps to the column/row it's dragged to.
Is there any easy-ish way to do this?
Honestly, if I could get the current row/column that it's over, then all I'd need to do is set the column/row of it to them and that would probably do it and then just worry about keeping it inside the grid.

I figured out a nice and fun way!
I worked out the position on the grid that the the mouse is on on the MouseUp event and then the relative position of the mouse on the control since it spans several rows/columns.
public void getPosition(UIElement element, out int col, out int row)
{
DControl control = parent as DControl;
var point = Mouse.GetPosition(element);
row = 0;
col = 0;
double accumulatedHeight = 0.0;
double accumulatedWidth = 0.0;
// calc row mouse was over
foreach (var rowDefinition in control.RowDefinitions)
{
accumulatedHeight += rowDefinition.ActualHeight;
if (accumulatedHeight >= point.Y)
break;
row++;
}
// calc col mouse was over
foreach (var columnDefinition in control.ColumnDefinitions)
{
accumulatedWidth += columnDefinition.ActualWidth;
if (accumulatedWidth >= point.X)
break;
col++;
}
}
I then take away the relative positions from the normal positions so that when you drop it, it always drops on the top left of the screen. When I move my controls, I use margins to move it, which screws up the position on the grid at the time, as shown below:
void Chart_PreviewMouseMove(object sender, MouseEventArgs e)
{
if (IsMouseCaptured)
{
Point mouseDelta = Mouse.GetPosition(this);
mouseDelta.Offset(-mouseOffset.X, -mouseOffset.Y);
Margin = new Thickness(
Margin.Left + mouseDelta.X,
Margin.Top + mouseDelta.Y,
Margin.Right - mouseDelta.X,
Margin.Bottom - mouseDelta.Y);
}
}
void Chart_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
mouseOffset = Mouse.GetPosition(this);
CaptureMouse();
parent.currentObject = this;
}
To tackle this, I simply reset the margin.
public void updatePosition()
{
Grid.SetRow(this, (int)position.Y);
Grid.SetColumn(this, (int)position.X);
Margin = new Thickness();
}
I hope this helps someone else since it was rather frustrating for me to find the answer and in the end I managed to get lots of little fragments of how to do things and eventually came up with my own solution.

Is there any easy-ish way to do this?
I'd say that the answer to this question very much depends on your experience using Drag and Drop functionality... for a beginner, I'd say that the answer to this was no, but for someone with some experience and some common sense, it might not be too bad.
To determine which Grid cell the user's mouse is over will not be straight forward. You can handle the PreviewDragOver event and use the VisualTreeHelper.HitTest method to check which control the mouse is currently over:
private void PreviewDragOver(object sender, DragEventArgs e)
{
HitTestResult hitTestResult = VisualTreeHelper.HitTest(adornedUIElement,
e.GetPosition(adornedUIElement));
Control controlUnderMouse = hitTestResult.VisualHit.GetParentOfType<Control>();
}
The GetParentOfType method is a useful extension method that I created, but you can convert it to a normal method easily enough:
public static T GetParentOfType<T>(this DependencyObject element) where T : DependencyObject
{
Type type = typeof(T);
if (element == null) return null;
DependencyObject parent = VisualTreeHelper.GetParent(element);
if (parent == null && ((FrameworkElement)element).Parent is DependencyObject) parent = ((FrameworkElement)element).Parent;
if (parent == null) return null;
else if (parent.GetType() == type || parent.GetType().IsSubclassOf(type)) return parent as T;
return GetParentOfType<T>(parent);
}
Of course, once you have a Control in your controlUnderMouse variable, you'll still have some considerable work to do as you work your way through the UIElements until you get to the Grid... you can of course make further use of the GetParentOfType method to make your job easier.

Customizing default inputs?

I wonder if it's possible to customize my C# application (winforms) to get a better design, I made a PSD (photoshop document) so I can generate png jpeg... pictures if I need them.
Example of a form like the one I want :

Indeed as it was pointed out in the comments, it is easy to use WPF (indows Presentation Foundation) to achieve that result, but if you really need that it must be made in windows forms I can help you with that...
ControlBox and Border
It seens that your form does not have a control box (minimize, maximize and close buttons)
to achieve that you can set
form.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None
I'm not sure if that galaxy behind your form is part of the application so i'll be considering that it is not
To achieve that irregular shape of the form we have to do a workaround here
Irregular Shape of the Form
we are going to set a Color to TransparentKey, so everything in the form in that specific color will be transparent, like it does not exists (if you click in that part it will go into de desktop or whatever application you have behind in your form)
So let's use a specific color which we will probably dont use in the form
form.TransparencyKey = Color.FromArgb(111, 111, 111); //You can do it by the editor
So in order to make that white part we are going to use an Panel and a PictureBox outsite of the Panel trying to copy the shape of your image
Stylized Inputs
To make it easier and reusable I'm going to make a userControl in this one
the usercontrol will have
a Panel called HighLightPanel, its dock property will be set to Fill
a Panel called BackColorPanel, it will be inside the HighLightPanel
a PictureBox called InputPicture, its dock property will be set to Left, it will be inside BackColorPanel and its acessor will be public
a TextBox called TextBox, its dock property wil be set to fill, it will be inside BackColorPanel, the BorderStyle Property set to None, you should set the size and font you most desize in this one, I'm going to use Segoe UI; 15,75pt and its acessor will be public
Now we have to make some properties in our UserControl to make it work without work in other controls
First in the SizeChanged event of the HighLightPanel we will make the BackColorPanel be exacly two points smaller in every direction and its position to 1;1 so we can see the HighLightPanel
private void HighlightPanel_SizeChanged(object sender, EventArgs e)
{
this.BackColorPanel.Size = new Size(
HighlightPanel.Width - 2,
HighlightPanel.Height - 2);
}
Now we will create two propertys to handle the Highlight Color
public Color HighlightBorderColor { get; set; }
public Color NonHighlightBorderColor { get; set; }
And in the Enter and Leave Property of our TextBox we are going to change the HighlightPanel
private void TextBox_Enter(object sender, EventArgs e)
{
HighlightPanel.BackColor = HighlightBorderColor;
}
private void TextBox_Leave(object sender, EventArgs e)
{
HighlightPanel.BackColor = NonHighlightBorderColor;
}
So now every time the user enter the Input it will appear that the Input has an Border in the specified Color
Now to enhance its usability to developers we will make some wrappers in its controls to be easier change property of child controls in the editor
public Image InputImage
{
get { return InputPicture.Image; }
set { InputPicture.Image = value; }
}
public PictureBoxSizeMode InputImageLayout
{
get { return InputPicture.SizeMode; }
set { InputPicture.SizeMode = value; }
}
public char PasswordCharacter
{
get { return TextBox.PasswordChar; }
set { TextBox.PasswordChar = value; }
}
public bool ShowInputImage
{
get { return InputPicture.Visible; }
set { InputPicture.Visible = value; }
}
In the InputImage set the picture you want for the User and the Key
Insert the two controls in the position you like
Position of the Form
if you want your form to be moveable without the border you will have to use this snippet, it is more easy in WPF
#region MoveForm
Point LastPoint;
bool ShouldMove;
private void form_MouseDown(object sender, MouseEventArgs e)
{
LastPoint = e.Location;
ShouldMove = true;
this.TransparencyKey = Color.FromArgb(111, 111, 111);
}
private void form_MouseUp(object sender, MouseEventArgs e)
{
ShouldMove = false;
}
private void form_MouseMove(object sender, MouseEventArgs e)
{
if (ShouldMove)
{
this.Location = new Point(
this.Location.X - LastPoint.X + e.X,
this.Location.Y - LastPoint.Y + e.Y);
}
}
#endregion

If you need a lot of special graphics effects learning WPF will indeed be a sound investement.
If all you want is that login screen, it is trivial in Winforms and doesn't take any horrible hacks as you've been told..
this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
this.BackColor = System.Drawing.Color.LavenderBlush;
this.TransparencyKey = System.Drawing.Color.LavenderBlush;
this.ControlBox = false;
this.MaximizeBox = false;
this.MinimizeBox = false;
this.Text= "";
These seven lines are all it takes for a form to be transparent. I copied them from the Designer code; you can simply set the 7 Properties in the property grid.
Now add a panel, dock it to the bottom and give it the right color; add a picturebox and your other controls and you are set.
To create the two input groups you also need just a few regular controls and only a few simple lines of code:
You place one Panel, BorderStyle = FixedSingle; and add a Label and a TextBox to it. The Label has AutoSize = False; and both ImageAlign and TextAlign are set to MiddleLeft. You assign an image to the Label's Image and prefix the Text with enough blanks to not overlap. Obviously you should define a PasswordChar for the 2nd TextBox. Now all you need is to script the Enter and Leave events to change the BackColor of the respective Panels between, say SystemColors.Control and SystemColors.MenuHighlight. Size the Labels to almost fill the Panels and you are done. Less code than the WPF version, I'd bet.
If you need such input an controls again and again, simply create Usercontrols for each type you need!
Here is an example of the limits you will hit: Wouldn't it be nice to add a dropshadow effect to the image? It is doable in Winforms. But it would involve painting that effect; this would take at least 15 or 20 lines of involved code instead of simply turning the effect on with (estimated) 1-3 simple lines.
Do you need any nice hover effects? Not easy, to say the least..
These limits will be all over the place, so it really depends on how fancy your requirements will get.
Maybe you should use this example as a starter to compare the two techniques and to warm you up to WPF?

How to hide and show panels on a form and have it resize to take up slack?

I have a form with three panels.
I want the top two to be a fixed height, and bottom one to fill the rest of the space.
The dialog is resizable, so all should change width on resixze, and bottom one should change height.
This is important, the user must be able to stretch the form, as well as the program through code.
If I set a panel to visible = false, I want the form height to shrink so the others stay the same height.
If I set a panel to visible = true, I want the form height to grow by the height of the panel.
I will control the hiding/showing of the panels with buttons. The idea is I show certain panels for "advanced" mode in my form, and hide them for "simple" mode. I cannot have a bunch of blank space if I hide a panel, and I want the form to shrink a bunch for simple mode.
I tried doing this with panels docked to top, but a form resize by the user will not change a panel height. So that is the main trick I am asking for help on.

Anyone in this kind of situation can use the below styling:
Use 2-3 Panel to Group different Controls and place them in a single parent control say a GroupBox.
Make all the child panels Dock to the same side say "Top".
if any of the panel is jumping over another due to similar docking. In Visual Studio, go to menu View > Other Windows > Document Outline and Set the display order. (https://msdn.microsoft.com/en-us/library/46xf4h0w%28v=vs.80%29.aspx)
Set the Panel property as follows:
AutoSize: true
AutoSizeMode: GrowAndShrink
Once the panel is not visible, other panel will take away the empty space.
Hope this helps!!!

the other posts are close, there is a detail missing that I included in the solution I came up with. Its a flag to tell if the sized event was caused by a user form resize, or the program doing it when a panel is shown or hidden.
For this solution, make a form with 4 panels.
Set dock to top for all panels. Do not set any autosizing for panels or form.
Also make two buttons and place on top panel, or any panel that you will not be hiding.
The code below shows how to handle the resized event, and the showing hiding buttons.
I made them hide/show panel 2, but the code should work for any panel.
namespace ProgTesting {
public partial class Form5 : Form {
private bool doNothing = false;
public Form5() {
InitializeComponent();
cmdAdvanced.Visible = false;
}
private void cmdSimple_Click(object sender, EventArgs e) {
if (panel2.Visible) {
panel2.Visible = false;
doNothing = true;
this.MinimumSize = new Size(this.Width, this.Height - panel2.Height);
this.Height = this.Height - panel2.Height;
doNothing = false;
cmdSimple.Visible = false;
cmdAdvanced.Visible = true;
}
}
private void cmdAdvanced_Click(object sender, EventArgs e) {
if (!panel2.Visible) {
panel2.Visible = true;
doNothing = true;
this.Height = this.Height + panel2.Height;
this.MinimumSize = new Size(this.Width, this.Height);
doNothing = false;
cmdAdvanced.Visible = false;
cmdSimple.Visible = true;
}
}
private void Form5_SizeChanged(object sender, EventArgs e) {
if (!doNothing)
if (panel2.Visible)
panel3.Height = this.ClientSize.Height - panel1.Height - panel2.Height - panel4.Height;
else
panel3.Height = this.ClientSize.Height - panel1.Height - panel4.Height;
}
}
}
You do have to manage the heights going on, which is a pain but gives you control. Some shots of it working:

It sounds like what you are looking for is an Expander. Essentially a control that consists of a header and a content area, where clicking on the header toggles the content area between visible and collapsed.
I'm not 100% certain if an Expander control will automatically adjust the height of a form when it expands/collapses though. You may need to hook up an event handler to the Expander to manually adjust the height of your form when the Expander collapses.
Try looking at the Stack Overflow Question Add an expander (collapse/expand) to a Panel WinForm. There are a number of links from that question about implementing an Expander in Windows Forms, including some that provide full source code.
Update:
I've knocked up a quick demo that will accomplish what you want, in a very primitive way, not using any of the various Expander controls out there. I think that while you will find the Expanders useful, I doubt they will adjust the size of the container they are inside, unless you write some adjustment code like I have below.
Create a form that looks like this:
The two text boxes are anchored Left, Top, Right.
The toggle button is anchored Left, Top, named btnTogglePanel.
The magenta panel is anchored Left, Top, Right, Bottom, named pnlToggled.
The bottom button is anchored Right, Bottom.
Then in the code behind for the form:
public partial class ToggleableExpanderForm : Form
{
public ToggleableExpanderForm()
{
InitializeComponent();
SizeChanged += (s, args) =>
{
if (_LastSize.HasValue)
{
var diff = Size - _LastSize.Value;
if (_LastHeight.HasValue
&& !IgnoreNextResizeForLastHeightAdjustment)
{
_LastHeight += diff.Height;
}
}
_LastSize = Size;
};
}
private Size? _LastSize;
private bool IgnoreNextResizeForLastHeightAdjustment = true;
private int? _LastHeight;
private void btnTogglePanel_Click(object sender, EventArgs e)
{
var newVisibility = !pnlToggled.Visible;
int heightAdjustment = 0;
if (newVisibility)
{
if (_LastHeight.HasValue)
{
heightAdjustment = _LastHeight.Value;
_LastHeight = null;
}
}
else
{
_LastHeight = pnlToggled.Height;
heightAdjustment = -pnlToggled.Height;
}
pnlToggled.Visible = newVisibility;
IgnoreNextResizeForLastHeightAdjustment = true;
Height += heightAdjustment;
}
}
Essentially you adjust the height of the form manually when the toggle button is clicked, based on whether or not the panel is hiding/showing. You also need to take into account of what will happen when the user resizes the form when the panel is invisible, which is where the cruft around listening to the SizeChanged event comes in. You need the answer to "how MUCH has the size changed" and then you adjust your previously stored panel height as appropriate.
I don't imagine the above code is perfect, and I haven't tested it in every use case, but it gets the basic job done.

One way to go about it is to use a TableLayoutPanel for the top two panels.
The steps below will give you the resizing desired when the user resizes the form.
Start by created a TableLayoutPanel (TLP) and shrink it down from the default 2 columns, 2 rows to just 2 columns, 1 row.
Anchor it to Top, Left, and Right
Now size the TLP to fit your top two panels and place each panel in a cell of the TLP.
Anchor these two panels to all sides.
Position the 3rd panel (Panel3) below the TLP to your liking and anchor it to all sides.
To handle the hiding of Panel3 some logic will need to be added to the appropriate button_Click event. Determine what size you would like the "minimized" height to be and then just store the form size when Panel3 is visible and restore the height when it's clicked again. It should look something like this.
private void button1_Click(object sender, EventArgs e)
{
if (panel3.Visible)
{
// make invisible
panel3.Visible = false;
// storedHeight is a private member of the Form
storedHeight = Form1.ActiveForm.Height;
Form1.ActiveForm.Height = minimumHeight; // Set to predetermined minimum height
}
else
{
// make visible
panel3.Visible = true;
Form1.ActiveForm.Height = storedHeight;
}
}
Now when you hide Panel3 the form will shrink to the size of the TLP, then grow again when Panel3 is visible. Also the top panels will expand in width, but not height. You will need to change the MinSize properties of the form and its value will have to be dynamically adjusted depending on whether Panel3 is visible or not.

How to Programmatically Scroll a Panel

I have a System.Windows.Forms.Panel with some content.
I am trying to programmatically scroll the panel (vertically) either up or down.
I have tried setting the AutoScrollPosition property to a new Point on the panel but that doesn't seem to do it.
I have the AutoScroll property set to true.
I even tried to set the VerticalScroll.Value twice as suggested here, but that doesn't seem to work either.
This is what I am currently doing:
//I have tried passing both positive and negative values.
panel.AutoScrollPosition = new Point(5, 10);
The X and Y values on AutoScrollPosition remain 0 and 0.
Any help or direction on this would be greatly appreciated it.
Thanks in advance,
Marwan

Here is a solution. I guess you can scroll your Panel by arbitrary position using Win32 however there is a simple trick to help you achieve your requirement here:
public void ScrollToBottom(Panel p){
using (Control c = new Control() { Parent = p, Dock = DockStyle.Bottom })
{
p.ScrollControlIntoView(c);
c.Parent = null;
}
}
//use the code
ScrollToBottom(yourPanel);
Or use extension method for convenience:
public static class PanelExtension {
public static void ScrollToBottom(this Panel p){
using (Control c = new Control() { Parent = p, Dock = DockStyle.Bottom })
{
p.ScrollControlIntoView(c);
c.Parent = null;
}
}
}
//Use the code
yourPanel.ScrollToBottom();
UPDATE
If you want to set the exact position, modifying the code above a little can help:
//This can help you control the scrollbar with scrolling up and down.
//The position is a little special.
//Position for scrolling up should be negative.
//Position for scrolling down should be positive
public static class PanelExtension {
public static void ScrollDown(this Panel p, int pos)
{
//pos passed in should be positive
using (Control c = new Control() { Parent = p, Height = 1, Top = p.ClientSize.Height + pos })
{
p.ScrollControlIntoView(c);
}
}
public static void ScrollUp(this Panel p, int pos)
{
//pos passed in should be negative
using (Control c = new Control() { Parent = p, Height = 1, Top = pos})
{
p.ScrollControlIntoView(c);
}
}
}
//use the code, suppose you have 2 buttons, up and down to control the scrollbar instead of clicking directly on the scrollbar arrows.
int i = 0;
private void buttonUp_Click(object sender, EventArgs e)
{
if (i >= 0) i = -1;
yourPanel.ScrollUp(i--);
}
private void buttonDown_Click(object sender, EventArgs e)
{
if (i < 0) i = 0;
yourPanel.ScrollDown(i++);
}
Another solution you may want to use is using Panel.VerticalScroll.Value. However I think you need more research to make it work as you expect. Because I can see once changing the Value, the scrollbar position and control position don't sync well. Notice that Panel.VerticalScroll.Value should be between Panel.VerticalScroll.Minimum and Panel.VerticalScroll.Maximum.

This surprisingly works! NOTE THE MINUS SIGN in the code. There is strange behavior in setting scroll position. If you set the position to exact value (50), it goes negative when you read it next time (-50). So you have to invert it before setting new scroll value.
Scroll down:
private void ButtonScrollDown_OnClick(object sender, EventArgs e)
{
Point current = yourScrollPanel.AutoScrollPosition;
Point scrolled = new Point(current.X, -current.Y + 10);
yourScrollPanel.AutoScrollPosition = scrolled;
}
Scroll up similarly, (-current.Y - 10)

If you have a class that derives from Panel, then call these two protected methods to scroll the panel:
// The bottom is off screen; scroll down. These coordinates must be negative or zero.
SetDisplayRectLocation(0, AutoScrollPosition.Y - item.BoundingRect.Bottom + ClientRectangle.Bottom);
AdjustFormScrollbars(true);
In my example, item.BoundingRect.Bottom is the Y coordinate of the bottom of a thumbnail, and I need to scroll the panel down so that the whole thumbnail is visible.
#King King's solution of creating a temporary Control just so that scrolling could be done seemed "heavy" to me. And #Hans Passant's suggestion of setting AutoScrollMinSize and AutoScrollPosition didn't work for me.
Leave AutoScroll to its default value of 'true'.

Try this:-
panel.ScrollControlIntoView(childcontrol);
This should work. childcontrol is the particular control that you want to show in your display area.

Setting the value of the HorizontalScroll property and then using the method ScrollControlIntoView works for me:
lpanel.HorizontalScroll.Value = 100;
lpanel.ScrollControlIntoView(lpanel);

Use #King King Answered Code and if you want to hide horizontal and vertical scroll bar, just apply the below code in the constructor or initialization.
yourPanel.AutoScroll = false;
yourPanel.HorizontalScroll.Maximum = 0;
yourPanel.HorizontalScroll.Visible = false;
yourPanel.VerticalScroll.Maximum = 0;
yourPanel.VerticalScroll.Visible = false;
yourPanel.AutoScroll = true;

I had an issue where I couldnt get my panel to scroll back to top . I tried many things to try and get the panel to scroll back to the top after populating it with many controls.
Nomatter what I did it always put the VScroll bar to the bottom.
After exhaustive testing I found it was because my controls had the TabStop property set to true (default on user controls) was causing the issue.
Setting TabStop to false fixed it.

Create an control that sits slightly outside the visible area (so -1 at the top and clientsize+1 ) and then call ScrollControlIntoView:
public static class PanelExtension {
public static void ScrollDown(this Panel p)
{
using (Control c = new Control() { Parent = p, Height = 1, Top = p.ClientSize.Height + 1 })
{
p.ScrollControlIntoView(c);
}
}
public static void ScrollUp(this Panel p )
{
using (Control c = new Control() { Parent = p, Height = 1, Top = -1})
{
p.ScrollControlIntoView(c);
}
}
}
//use the code, suppose you have 2 buttons, up and down to control the scrollbar instead of clicking directly on the scrollbar arrows.
private void buttonUp_Click(object sender, EventArgs e)
{
yourPanel.ScrollUp();
}
private void buttonDown_Click(object sender, EventArgs e)
{
yourPanel.ScrollDown();
}
with yourpanel.SetAutoScrollMargin(1, 1); you can set very fine scrolling steps and then take a timer to call the srolling when buttons are down