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How to scrollUp or down in panel with Mouse_Wheel Events without using Scrollbar Winforms

Example:
I have a Panel or flowLayoutpanel so I want to scroll look into items without using scrollbar, instead I want to use MouseWheel
So I was wondering is there any way that you can scroll up or down in a panel or flowLayoutPanel
Without use 'Auto Scroll= true' instead I want to moveViewPanel up or down when mouse scrolled.
If you get what I mean
These are some code that I used with but seemed not to work at all
--Sameple1
void Panel2_mWheel(object sender, MouseEventArgs e)
{
//Get cursor position
Point mousePoint = new Point(e.X, e.Y);
//Change to the location of the form of this form
mousePoint.Offset(this.Location.X, this.Location.Y);
if (panel2.RectangleToScreen(panel2.DisplayRectangle).Contains(mousePoint))
{
Console.WriteLine("Contain");
panel2.AutoScrollPosition = new Point(0, panel2.VerticalScroll.Value - e.Delta);
}
}
--Sample2
Panel.MouseEnter += C_MouseEnter;
void Panel_MouseEnter(object sender, EventArgs e)
{
c.Focus();
}
--sample3
panel.MouseWheel += pn_MouseWheel;
private void pn_MouseWheel(object sender, MouseEventArgs e)
{
int deltaScroll = 10;
if (e.Delta > 0)
{
if (pnlContain.VerticalScroll.Value - deltaScroll >= pnlContain.VerticalScroll.Minimum)
pnlContain.VerticalScroll.Value -= deltaScroll;
else
pnlContain.VerticalScroll.Value = pnlContain.VerticalScroll.Minimum;
}
else
{
if (pnlContain.VerticalScroll.Value + deltaScroll <= pnlContain.VerticalScroll.Maximum)
pnlContain.VerticalScroll.Value += deltaScroll;
else
pnlContain.VerticalScroll.Value = pnlContain.VerticalScroll.Maximum;
}
--sample 4
panel_wheel(object sender, MouseEventArgs e)
{
if(e.OldValue>e.NewValue)
{
//Scroll up Do stuff
}
else
{
//Scroll down Do stuff
}
}
Anyone help me please!!

How to stop this flickering issue ,which occurs when the UI element is moved using touch?

I have a problem when I try to move the textblock using touch there is a flickering issue which does not occur when I do the same using mouse interaction. can someone help me here?
How to Stop this flickering issue?
public partial class MainWindow: Window
{
Canvas can = new Canvas() { Background=Brushes.White};
Grid grid = new Grid() { Height=150,Width=100,Background=Brushes.Yellow};
TextBlock textBlock = new TextBlock() { Text = "TextBlock Text" ,FontWeight=FontWeights.Bold };
Point point = new Point();
public MainWindow()
{
InitializeComponent();
grid.Children.Add(textBlock);
can.Children.Add(grid);
Canvas.SetLeft(grid, 0);
Canvas.SetTop(grid, 0);
textBlock.PreviewMouseDown += TextBlock_PreviewMouseDown;
textBlock.PreviewTouchDown += TextBlock_PreviewTouchDown;
can.PreviewMouseMove += Can_PreviewMouseMove;
can.PreviewTouchMove += Can_PreviewTouchMove;
m_grid.Children.Add(can);
}
private void TextBlock_PreviewTouchDown(object sender, TouchEventArgs e)
{
point = e.GetTouchPoint(this).Position;
}
private void TextBlock_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
point = e.GetPosition(this);
}
private void Can_PreviewTouchMove(object sender, TouchEventArgs e)
{
if (e.OriginalSource is TextBlock )
{
Canvas.SetLeft(grid, e.GetTouchPoint(this).Position.X - point.X);
Canvas.SetTop(grid, e.GetTouchPoint(this).Position.Y - point.Y);
}
}
private void Can_PreviewMouseMove(object sender, MouseEventArgs e)
{
if(e.OriginalSource is TextBlock && e.LeftButton==MouseButtonState.Pressed&&e.StylusDevice==null)
{
Canvas.SetLeft(grid, e.GetPosition(this).X - point.X);
Canvas.SetTop(grid, e.GetPosition(this).Y - point.Y);
}
}
}

I wasn't able to reproduce the flickering you're encountering, but I think it may be due to your implementation of drag/touch and drop.
The first problem I encountered with the code you posted was in the PreviewTouchDown and PreviewMouseDown event handlers. The code was setting the point to be relative to this - the Window - which when you first drag is okay, but after that any other drag attempt will immediately move the item up to the top/left corner.
To fix this, I edited the event handlers to set point to be relative to the grid so that the drag calculations would be correct on subsequent drags.
The second problem is that you are not capturing the mouse or touch device when dragging, which when dragging near the edge of the grid will cause the drag to stop. Capturing the mouse or touch will also make the drag much smoother.
To fix this, I added mouse and touch capture to the PreviewTouchDown and PreviewMouseDown event handlers, and added TouchUp and MouseUp event handlers that release the capture.
Here's the updated code in full:
public partial class MainWindow : Window
{
private Canvas can = new Canvas() { Background = Brushes.White };
private Grid grid = new Grid() { Height = 150, Width = 100, Background = Brushes.Yellow };
private TextBlock textBlock = new TextBlock() { Text = "TextBlock Text", FontWeight = FontWeights.Bold };
private Point point = new Point();
public MainWindow()
{
InitializeComponent();
grid.Children.Add(textBlock);
can.Children.Add(grid);
Canvas.SetLeft(grid, 0);
Canvas.SetTop(grid, 0);
textBlock.PreviewMouseDown += TextBlock_PreviewMouseDown;
textBlock.PreviewTouchDown += TextBlock_PreviewTouchDown;
textBlock.MouseUp += TextBlock_MouseUp;
textBlock.TouchUp += TextBlock_TouchUp;
can.PreviewMouseMove += Can_PreviewMouseMove;
can.PreviewTouchMove += Can_PreviewTouchMove;
RootGrid.Children.Add(can);
}
private void TextBlock_PreviewTouchDown(object sender, TouchEventArgs e)
{
point = e.GetTouchPoint(grid).Position;
e.TouchDevice.Capture(textBlock);
}
private void TextBlock_PreviewMouseDown(object sender, MouseButtonEventArgs e)
{
point = e.GetPosition(grid);
e.MouseDevice.Capture(textBlock);
}
private void TextBlock_TouchUp(object sender, TouchEventArgs e)
{
e.TouchDevice.Capture(null);
}
private void TextBlock_MouseUp(object sender, MouseButtonEventArgs e)
{
e.MouseDevice.Capture(null);
}
private void Can_PreviewTouchMove(object sender, TouchEventArgs e)
{
if (e.OriginalSource is TextBlock)
{
Canvas.SetLeft(grid, e.GetTouchPoint(this).Position.X - point.X);
Canvas.SetTop(grid, e.GetTouchPoint(this).Position.Y - point.Y);
}
}
private void Can_PreviewMouseMove(object sender, MouseEventArgs e)
{
if (e.OriginalSource is TextBlock && e.LeftButton == MouseButtonState.Pressed && e.StylusDevice == null)
{
Canvas.SetLeft(grid, e.GetPosition(this).X - point.X);
Canvas.SetTop(grid, e.GetPosition(this).Y - point.Y);
}
}
}
I hope this is helpful.

How to regain focus in application after drag and drop to grid

In my application, I have a form with two panels. Inside one panel is a button. Inside the other is a DevExpress Grid control. The grid is made up of 3 columns. You can drag values from one column into the other to copy it.
My problem is that whenever I do a drag-and-drop from one column to another, the focus on the application goes into an unusual state. The grid remains focused; I can mouse over the headers and see them react as normal. However the rest of the application is not focused. Mouse over the button in the other panel does not react, nor do the menus or form controls. If I click on the button, it reacts like I clicked on an unfocused application. I have to click again to actually activate the button. Same for every control except the grid.
I have tried using Activate() and Focus() on the button and form but to no avail.
namespace Company.StuffUploader
{
public partial class ComputationGrid : DevExpress.XtraEditors.XtraUserControl
{
private BindingList<ComputationLinkModel> _links = new BindingList<ComputationLinkModel>();
public List<ComputationLinkModel> ComputationLinkModels
{
get
{
return new List<ComputationLinkModel>(_links);
}
}
public ComputationGrid()
{
InitializeComponent();
}
private void ComputationGrid_Load(object sender, EventArgs e)
{
_gridControl.DataSource = _links;
}
private DragDropEffects GetDragEffect(DragEventArgs e)
{
var text = e.Data.GetData("System.String") as string;
if (text == null)
return DragDropEffects.None;
var link = GetLinkFromScreenPoint(new Point(e.X, e.Y));
if (link == null)
return DragDropEffects.None;
var tokens = text.Split('\t');
if (tokens.Count() != 2)
return DragDropEffects.None;
var dateString = link.movedate.ToString("yyyy-MM-dd");
if (link.StuffSurfaceName == tokens[0] && dateString != tokens[1])
return DragDropEffects.Move;
else
return DragDropEffects.None;
}
private ComputationLinkModel GetLinkFromScreenPoint(Point screenPt)
{
var pt = _gridControl.PointToClient(screenPt);
var hitInfo = _gridView.CalcHitInfo(pt);
return _gridView.GetRow(hitInfo.RowHandle) as ComputationLinkModel;
}
private void _gridControl_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
var hitInfo = _gridView.CalcHitInfo(e.Location);
if (hitInfo == null || !hitInfo.InRowCell)
return;
// Only allow dragging from target column
if (hitInfo.Column.AbsoluteIndex != 0)
return;
var link = _gridView.GetRow(hitInfo.RowHandle) as ComputationLinkModel;
if (link == null)
return;
var item = string.Format("{0}\t{1}", link.StuffSurfaceName, link.movedate.ToString("yyyy-MM-dd"));
DoDragDrop(item, DragDropEffects.Move);
}
}
private void _gridControl_DragOver(object sender, DragEventArgs e)
{
e.Effect = GetDragEffect(e);
}
private void _gridControl_DragDrop(object sender, DragEventArgs e)
{
}
private void _gridControl_DragEnter(object sender, DragEventArgs e)
{
e.Effect = GetDragEffect(e);
}
private void _unlinkButton_Click(object sender, EventArgs e)
{
}
}
}

I figured out my own problem. Calling DoDragDrop() from within MouseDown event does not seem to work correctly. The proper way is to call it from MouseMove(). The documentation on MSDN hints at this in its example code.

Ensure that you set the DXMouseEventArgs.Handled property to true in the GridView's Mouse~ event handlers. It guarantees that default handling of these events will be prohibited. Review this example to see how to do this.

Drag and drop an to TextBox in a specific mouse position - Show caret or position indicator

I am pasting an item from a TreeView to a TextBox, but I want to paste that item in the mouse's current position and also show a caret like the image below.
Image with caret:
Here is my code:
private void tvOperador_ItemDrag(object sender, ItemDragEventArgs e)
{
var node = (TreeNode)e.Item;
if (node.Level > 0)
{
DoDragDrop(node.Text, DragDropEffects.Copy);
}
}
private void txtExpresion_DragEnter(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(string))) e.Effect = DragDropEffects.Copy;
}
private void txtExpresion_DragDrop(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(System.String)))
{
string Item = (System.String)e.Data.GetData(typeof(System.String));
string[] split = Item.Split(':');
txtExpresion.Text += split[1];
}
}

This is tricky as the Drag&Drop operation keeps the mouse captured, so you can't use the mouse events..
One way is to set up a Timer to do the work..:
Timer cursTimer = new Timer();
void cursTimer_Tick(object sender, EventArgs e)
{
int cp = txtExpresion.GetCharIndexFromPosition(
txtExpresion.PointToClient(Control.MousePosition));
txtExpresion.SelectionStart = cp;
txtExpresion.SelectionLength = 0;
txtExpresion.Refresh();
}
The Timer uses the Control.MousePosition function to determined the cursor position every 25ms or so, sets the caret and updates the TextBox.
In your events you initialize it and make sure the TextBox has focus; finally you add the string at the current selection:
private void txtExpresion_DragEnter(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(string)))
{
e.Effect = DragDropEffects.Copy;
txtExpresion.Focus();
cursTimer = new Timer();
cursTimer.Interval = 25;
cursTimer.Tick += cursTimer_Tick;
cursTimer.Start();
}
}
private void txtExpresion_DragDrop(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(System.String)))
{
cursTimer.Stop();
string Item = (System.String)e.Data.GetData(typeof(System.String));
string[] split = Item.Split(':');
txtExpresion.SelectedText = split[1]
}
}
A different way to solve it would be to not use normal Drag&Drop and only code the mouse events but this one worked ok a my first tests.
Update
While the above solution does work, using a Timer seems not exactly elegant. Much better to use the DragOver event, as seen in Reza's answer. But instead of painting a cursor, why not do the real thing, i.e. take control of the actual I-beam..?
The DragOver event is called all the time during the move so it works pretty much like MousMove would: So here is a merger of the two solutions, which I believe is the best way to do it:
private void txtExpresion_DragDrop(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(System.String)))
{
string Item = (System.String)e.Data.GetData(typeof(System.String));
string[] split = Item.Split(':');
txtExpresion.SelectionLength = 0;
txtExpresion.SelectedText = split[1];
}
}
private void txtExpresion_DragEnter(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(string)))
{
e.Effect = DragDropEffects.Copy;
txtExpresion.Focus();
}
}
private void txtExpresion_DragOver(object sender, DragEventArgs e)
{
int cp = txtExpresion.GetCharIndexFromPosition(
txtExpresion.PointToClient(Control.MousePosition));
txtExpresion.SelectionStart = cp;
txtExpresion.Refresh();
}

You can draw a caret over TextBox in DragOver event. Also set the SelectionStart to the char index you get from mouse position. Then in DragDrop event, just set SelectedText.
private void textBox1_DragOver(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(System.String)))
{
var position = textBox1.PointToClient(Cursor.Position);
var index = textBox1.GetCharIndexFromPosition(position);
textBox1.SelectionStart = index;
textBox1.SelectionLength = 0;
textBox1.Refresh();
using (var g = textBox1.CreateGraphics())
{
var p = textBox1.GetPositionFromCharIndex(index);
g.DrawLine(Pens.Black, p.X, 0, p.X, textBox1.Height);
}
}
}
private void textBox1_DragDrop(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(System.String)))
{
string txt = (System.String)e.Data.GetData(typeof(System.String));
textBox1.SelectedText = txt;
}
}

Making a panel draggable

I am creating a "cropping tool", and i need to make a panel that contains 2 buttons draggable.
Until now i've tried something like this, but the change location event happens only when i click the right button of the mouse...
this.MouseDown += new MouseEventHandler(onRightClickMouse);
private void onRightClickMouse(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
Point localMouseClickPoint = new Point(e.X, e.Y);
panel1.Location = localMouseClickPoint;
}
}
My question: How can i make that panel draggable in my form?(I mean click on the panel then drag it to a location).

Try something like this:
delegate void updatePanelCallback();
panel1.MouseDown += new MouseEventHandler(onMouseDown);
panel1.MouseUp += new MouseEventHandler(onMouseUp);
System.Timers.Timer runTimer = new System.Timers.Timer(100);
runTimer.Elapsed += new ElapsedEventHandler(onTimerElapsed);
private void onMouseDown(object sender, MouseEventArgs e)
{
if (e.Button != MouseButtons.Right)
{
return;
}
runTimer.Enabled = false;
}
private void onMouseUp(object sender, MouseEventArgs e)
{
runTimer.Enabled = false;
}
public void updatePanelLocation()
{
if (this.InvokeRequired)
{
this.Invoke(new updatePanelCallback(updatePanelLocation), new object[] {});
}
else
{
Cursor curs = new Cursor(Cursor.Current.Handle);
panel1.Location = curs.Position;
}
}
private void onTimerElapsed(object source, ElapsedEventArgs e)
{
updatePanelLocation();
}

You could try something in two steps, preparing the action on MouseDown event and finishing it on MouseUp.