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Focus on scroll

I have a user control with a scrollbar (scrollbar appears as a contained user control, which inherits from Panel, is too large). When using the mouse to scroll all is well, but trying to scroll with the mousewheel dont work.
My solution here is to set focus to my child-control in an eventhandler for Scroll. This works. Now the question; Will this result in a lot of unecessary calls to childControl.Focus()? Is there a more neat way of doing this?
Edit: I think I was a bit unclear with my question so Rephrasing the question:
is
private void ChildControl_OnScroll(object sender, ScrollEventArgs scrollEventArgs)
{
this.childControl.Focus();
}
a bad way of setting the focus? I.e. will the focus be set mutliple times each time I scroll? or rather, will this cause (tiny) performance issues.

Here's another approach that gives focus when the scrollbar area of panel1 inside SomeUserControl is clicked. It uses NativeWindow so you don't have to change the panel in your UserControl. This way Focus() will only be called once, when the mouse goes down in the scrollbar area:
public partial class SomeUserControl : UserControl
{
private TrapMouseDownOnScrollArea trapScroll = null;
public SomeUserControl()
{
InitializeComponent();
this.VisibleChanged += new EventHandler(SomeUserControl_VisibleChanged);
}
void SomeUserControl_VisibleChanged(object sender, EventArgs e)
{
if (this.Visible && trapScroll == null)
{
trapScroll = new TrapMouseDownOnScrollArea(this.panel1);
}
}
private class TrapMouseDownOnScrollArea : NativeWindow
{
private Control control = null;
private const int WM_NCLBUTTONDOWN = 0xA1;
public TrapMouseDownOnScrollArea(Control ctl)
{
if (ctl != null && ctl.IsHandleCreated)
{
this.control = ctl;
this.AssignHandle(ctl.Handle);
}
}
protected override void WndProc(ref Message m)
{
switch (m.Msg)
{
case WM_NCLBUTTONDOWN:
if (this.control != null)
{
Rectangle screenBounds = control.RectangleToScreen(new Rectangle(0, 0, control.Width, control.Height));
if (screenBounds.Contains(Cursor.Position))
{
control.Focus();
}
}
break;
}
base.WndProc(ref m);
}
}
}
This might be overkill for your scenario, but it demonstrates one way to trap lower level messages. As said before, you could also derive from Panel to achieve the same affect. You could also trap messages at the application level with IMessageFilter.

The MouseWheel event is an event that "bubbles". Windows sends it to the control that has the focus, regardless of where the mouse cursor is located. The most typical problem is that you have a control that cannot receive the focus. A Panel for example.
This changes when you put a control on the panel. Now that control can get the focus and gets the MouseWheel message. It won't have any use for it so the message passes to its parent. Which does have a use for it, the panel scrolls as expected.
You can get a focusable panel control from this answer. A generic "make it work like a browser or Office program" solution from this question

If childControl has a MouseEnter() event then use that instead:
private void childControl_MouseEnter(object sender, EventArgs e)
{
childControl.Focus();
}
Then the mouse wheel events should be direct to childControl.

C#.NET MDI bugs when programmatically hiding and showing again a maximized child form and when maximized, child form's icon cannot be changed

Basically I am having two problems with C#.NET MDI. You can download VS2010 solution which reproduces bugs here.
1) When programmatically hiding and showing again a maximized child form, it is not maximized properly again and becomes neither maximized or in normal state.
childForm = new Form();
childForm.Text = "Child Form";
childForm.MdiParent = this;
...
private void showButton_Click(object sender, EventArgs e)
{
childForm.Visible = true;
}
...
private void hideButton_Click(object sender, EventArgs e)
{
childForm.Visible = false;
}
When child form is maximized, then programicaly hidden and shown again, it becomes something like this (please notice the menu bar - child form's control box appears, but child form is not maximized):
At this stage, child form cannot be moved around. However, I found a workaround for that, simply by showing and hiding a dummy child form, which forces the actual child form to become properly maximized. But this makes MDI area to flicker. Tried Invalidate, Refresh, Update methods, but they don't help. Maybe there are other workarounds to overcome this bug and not to make MDI area flicker with dummy child form?
private void workaround1Button_Click(object sender, EventArgs e)
{
dummyForm.Visible = true;
dummyForm.Visible = false;
}
2) When child form is maximized, the icon of the child form is displayed on menu bar. However, if you have to change the icon while the child form is maximized, the icon on the menu bar is not being refreshed (see the image above). I found a workaround for that too, which basically hides and shows menu bar. Icon gets refreshed, but it makes everything below menu bar to flicker. Tried Invalidate, Refresh, Update methods, but they don't help. Is there any other way to make menu bar to refresh the child form's icon?
private void workaround2Button_Click(object sender, EventArgs e)
{
menuStrip.Visible = false;
menuStrip.Visible = true;
}
Also I noticed that when parent form is in normal window state mode (not maximized) and you change the width or height of the form by 1 pixel, child form becomes maximized as it should be and child form's icon on menu bar gets refreshed properly and you don't need other workaround I described above. If I change the size of the form programicaly, form flickers by 1 pixel and I cannot do that, when parent form is maximized. Is there any way how I could invoke the repaint/refresh functionality which is called when you resize a form and which makes child form become maximized properly and the icon on the menu bar refreshed?

There's a bug in the implementation of the internal MdiControlStrip class, the control that displays the icon and the min/max/restore glyphs in the parent window. I haven't characterized it as yet, the code isn't that easy. A classic side effect of the bug is that the glyphs get doubled up, you found some other side-effects. The fix is simple though, delay creating the child windows until after the constructor is completed. Like this:
public MainForm()
{
InitializeComponent();
}
protected override void OnLoad(EventArgs e) {
childForm = new Form();
childForm.Text = "Child Form";
childForm.MdiParent = this;
dummyForm = new Form();
dummyForm.MdiParent = this;
dummyForm.WindowState = FormWindowState.Maximized;
base.OnLoad(e);
}

Have you tired using Hide/Show instead of setting visible to true/false?
Try:
private void showButton_Click(object sender, EventArgs e)
{
childForm.Show();
}
private void hideButton_Click(object sender, EventArgs e)
{
childForm.Hide();
}

How about this workaround?
private void showButton_Click(object sender, EventArgs e)
{
childForm.Visible = true;
childForm.WindowState = (FormWindowState)childForm.Tag;
}
private void hideButton_Click(object sender, EventArgs e)
{
childForm.Visible = false;
childForm.Tag = childForm.WindowState;
childForm.WindowState = FormWindowState.Normal;
}
UPDATE
I just gave you the idea how you could do. A better solution using the same idea as above would be a new base form which saves the windows state. See below. Derive your forms from FixedForm instead of Form:
public partial class FixedForm : Form
{
private FormWindowState lastWindowState;
public FixedForm()
{
InitializeComponent();
}
protected override void OnVisibleChanged(EventArgs e)
{
base.OnVisibleChanged(e);
if (Visible)
{
WindowState = lastWindowState;
}
else
{
lastWindowState = WindowState;
WindowState = FormWindowState.Normal;
}
}
}

Found a way how to come around those bugs.
First of all you need to suspend painting for a form and its children. I found a very helpful thread here, which describes how to do it.
After suspending painting, you need call UpdateBounds method of the control and increase ClientRectangle Width or Height by one and then decrease it back to the same value it was before. This invokes layout functionality which makes everything to update/repaint. Last step is to enable painting. Not very nice solution I guess, but it works.
StopDrawing();
UpdateBounds(Location.X, Location.Y, Width, Height, ClientRectangle.Width, ClientRectangle.Height + 1);
UpdateBounds(Location.X, Location.Y, Width, Height, ClientRectangle.Width, ClientRectangle.Height - 1);
StartDrawing();
I find suspending painting very helpful not only for working around those two bugs, but also in general to make GUI work more smoothly. I guess this can help to remove any kind of flickering. However, this solution requires P/Invokes, which should be avoided in general.

Why not just manually reset required icon in menuStrip items, after the creation of the window:
menuStripMain.Items[0].Image = null;

Combine NotifyIcon and ToolTip

I have been working with NotifyIcon in order to show an icon in the taskbar.
This program has no Windows Form. I perhaps could create one and make it invisible but I was hoping to avoid it. The ToolTip functions attached to NotifyIcon are somewhat lacking, and one of the gurus here suggested I look at the ToolTip functionality. It is possible to attach ToolTip to a form. Is is possible to attach it to just the NotifyIcon? I'm trying do this:
NotifyIcon CTicon = new NotifyIcon();
ToolTip toolTip = new ToolTip();
toolTip.SetToolTip(CTicon, "Test");
And I get the error "cannot convert from 'System.Windows.Forms.NotifyIcon' to 'System.Windows.Forms.Control'. Is there a way to convert? I also tried:
toolTip.SetToolTip(CTicon.Container, "Test");
but a container is apparently not a valid control either.
I apologize for my total lack of understanding of how this may or may not work.
Thanks in advance.

A belated answer, but maybe useful for others .
NotifyIcon.Text = "ToolTipText";

Tray icons don't support square tool tips, only balloons. Kinda makes sense, the icons are usually quite close together so it would be hard to see what icon produced the tip without the "stem" on the balloon. Use the NotifyIcon.BalloonTipText property.

NotifyIcon is used for the system tray icon that you see on the bottom right hand corner of the screen, usage of ToolTip is only for controls such as textboxes, checkboxes and so on...for example, let's assume there's a TextBox instance called 'textBox1', on the form than this would work:
toolTip1.SetToolTip(textBox1, "Hello World");
Now, when you mouse-over the textbox, a tooltip is shown...

I'm not sure you can set a tooltip directly on a notify icon. It's the same thing as setting the text property on the notify icon itself. There are some limitations to the notify icon text. It's limited to 128 chars and will only stay up for a short amount of time. If you want to display more info for a longer amount of time you should look at the balloon text property of the notify icon. I highly suggest reading the MSDN page it's quite helpful.
http://msdn.microsoft.com/en-us/library/system.windows.forms.notifyicon.aspx

You shouldn't.
NotifyIcon is used to show notifications, whereas ToolTip is used to show the information about the user's current activity, it should be used "in place".
Check the user interface guidelines:
Notifications
Balloons

All the tray icons on my computer have tooltips. You need to create your NotifyIcon using the constructor that accepts a Component as an argument. It displays the NotifyIcon.Text property.
I was able to create one using the example code here:
http://msdn.microsoft.com/en-us/library/1by05f8d.aspx
using System;
using System.Drawing;
using System.Windows.Forms;
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.NotifyIcon notifyIcon1;
private System.Windows.Forms.ContextMenu contextMenu1;
private System.Windows.Forms.MenuItem menuItem1;
private System.ComponentModel.IContainer components;
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
public Form1()
{
this.components = new System.ComponentModel.Container();
this.contextMenu1 = new System.Windows.Forms.ContextMenu();
this.menuItem1 = new System.Windows.Forms.MenuItem();
// Initialize contextMenu1
this.contextMenu1.MenuItems.AddRange(
new System.Windows.Forms.MenuItem[] {this.menuItem1});
// Initialize menuItem1
this.menuItem1.Index = 0;
this.menuItem1.Text = "E&xit";
this.menuItem1.Click += new System.EventHandler(this.menuItem1_Click);
// Set up how the form should be displayed.
this.ClientSize = new System.Drawing.Size(292, 266);
this.Text = "Notify Icon Example";
// Create the NotifyIcon.
this.notifyIcon1 = new System.Windows.Forms.NotifyIcon(this.components);
// The Icon property sets the icon that will appear
// in the systray for this application.
notifyIcon1.Icon = new Icon("appicon.ico");
// The ContextMenu property sets the menu that will
// appear when the systray icon is right clicked.
notifyIcon1.ContextMenu = this.contextMenu1;
// The Text property sets the text that will be displayed,
// in a tooltip, when the mouse hovers over the systray icon.
notifyIcon1.Text = "Form1 (NotifyIcon example)";
notifyIcon1.Visible = true;
// Handle the DoubleClick event to activate the form.
notifyIcon1.DoubleClick += new System.EventHandler(this.notifyIcon1_DoubleClick);
}
protected override void Dispose( bool disposing )
{
// Clean up any components being used.
if( disposing )
if (components != null)
components.Dispose();
base.Dispose( disposing );
}
private void notifyIcon1_DoubleClick(object Sender, EventArgs e)
{
// Show the form when the user double clicks on the notify icon.
// Set the WindowState to normal if the form is minimized.
if (this.WindowState == FormWindowState.Minimized)
this.WindowState = FormWindowState.Normal;
// Activate the form.
this.Activate();
}
private void menuItem1_Click(object Sender, EventArgs e) {
// Close the form, which closes the application.
this.Close();
}
}

How to handle Form caption right click

I'd like a context menu on the caption bar right click
any tips/samples pref in c# ?
UPDATE - for various reasons, right click on the form won't work because the form is not empty and the form is composited dynamically so....

You can do this by trapping the WM_NCRBUTTONDOWN notification that Windows sends when the user right-clicks the title bar. The control class does not have an event for it, you'll need to override WndProc(). Here's an example form, you'll need to add a ContextMenuStrip:
public partial class Form1 : Form {
public Form1() {
InitializeComponent();
}
protected void OnTitlebarClick(Point pos) {
contextMenuStrip1.Show(pos);
}
protected override void WndProc(ref Message m) {
const int WM_NCRBUTTONDOWN = 0xa4;
if (m.Msg == WM_NCRBUTTONDOWN) {
var pos = new Point(m.LParam.ToInt32());
OnTitlebarClick(pos);
return;
}
base.WndProc(ref m);
}
}

MSDN explains how to handle right-clicks on Windows Forms controls. Controls, including Forms, inherit the MouseClick event.
MouseEventArgs will tell you what button was clicked through the Button property. Have a look at the MouseButtons Enumeration.

if you handle the form mouse-click, you can then use the following code:
private void Dialog_MouseClick(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
this.Text = "new caption text";
}
}
But you'll have to make sure that you generate this event for the top-level control on a form. For instance if you have a group box on the form, it will receive the mouse-click events rather than the form itself, for the areas of the form that are under the group box.

There is already a menu managed by Windows when you right-click the titlebar.
Do you want to replace it completely?
If you want to add to it you will have to use the Win32 API and interop and you will have to subclass the form.
See the AppendMenu() function.

Basically you need to use p-invoke to do this. There is a really great example at Here
You can see from the example you will need to manually mimic the event handlers, but this is pretty straight forward.

You can override WndProc of the form and capture the WM_NCRBUTTONDOWN message:
protected override void WndProc(ref Message m)
{
const int WM_NCRBUTTONDOWN = 0xA4;
if (m.Msg == WM_NCRBUTTONDOWN)
{
MessageBox.Show("Caption right clicked!");
}
else
{
base.WndProc(ref m);
}
}
This code will suppress the window's context menu, however. You may not wish this. The WM_NCRBUTTONDOWN message will also be sent if you right click the window borders as well. You may not desire this either.

Modifying or hiding a form's caption tooltip

We have an MDI form which contains some number of child forms which have varying captions showing the currently loaded document's filename. When the child forms are maximized their title text gets placed in the parent window's title bar which often results in the text being too long to fit in the bar and Windows is nice enough to add ellipses and truncate the text.
However, when you hover over the title bar of the main window, it shows a tooltip with what should be the entire string, but instead the tooltip often contains a small fraction of the string. For example, if the main form's text was:
Program1 - Filename:[Really_long_filename_that_doesnt_fit.file]
It would appear as the following in the tooltip:
Program1 - Filename:[Really_long_filename_t
Edit: It always truncates the tooltip at exactly 100 characters, which leads me to believe that it's some upper limit specified somewhere.
Is there a way to change this so it displays the entire string, or if not, to disable the tooltip altogether?
Any language is acceptable, although we're doing this in C#.

This uses a manual tooltip and timer to show / hide a caption when the mouse moves over the title bar.
public partial class Form1 : Form
{
private ToolTip toolTip = new ToolTip();
private Timer toolTipTimer = new Timer();
private bool canShowToolTip = true;
protected override void WndProc(ref Message m)
{
switch (m.Msg)
{
case 0x2A0: // WM_NCMOUSEHOVER
return;
case (int)0x00A0: // WM_NCMOUSEMOVE
if (m.WParam == new IntPtr(0x0002)) // HT_CAPTION
{
if (canShowToolTip)
{
canShowToolTip = false;
toolTip.Show(this.Text, this, this.PointToClient(Cursor.Position), toolTip.AutoPopDelay);
toolTipTimer.Start();
}
}
return;
}
base.WndProc(ref m);
}
public Form1()
{
InitializeComponent();
Form child = new Form();
child.Text = "Program1 - Filename:[Really_long_filename_that_doesnt_fit.file] AAAAAAAAAAAAAAAAAAAA BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
child.MdiParent = this;
child.Show();
toolTip.AutoPopDelay = 5000;
toolTipTimer.Interval = toolTip.AutoPopDelay;
toolTipTimer.Tick += delegate(object sender, EventArgs e)
{
canShowToolTip = true;
};
}
}

I wish I had something more helpful for you, but unfortunately, I don't think that there's a way around this. You may either shorten your filenames or have to deal with it :(