You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
65 lines
2.1 KiB
C#
65 lines
2.1 KiB
C#
using System;
|
|
using System.Windows.Forms;
|
|
|
|
namespace Mesnac.Docking
|
|
{
|
|
// Inspired by Chris Sano's article:
|
|
// http://msdn.microsoft.com/smartclient/default.aspx?pull=/library/en-us/dnwinforms/html/colorpicker.asp
|
|
// In Sano's article, the DragForm needs to meet the following criteria:
|
|
// (1) it was not to show up in the task bar;
|
|
// ShowInTaskBar = false
|
|
// (2) it needed to be the top-most window;
|
|
// TopMost = true (not necessary here)
|
|
// (3) its icon could not show up in the ALT+TAB window if the user pressed ALT+TAB during a drag-and-drop;
|
|
// FormBorderStyle = FormBorderStyle.None;
|
|
// Create with WS_EX_TOOLWINDOW window style.
|
|
// Compares with the solution in the artile by setting FormBorderStyle as FixedToolWindow,
|
|
// and then clip the window caption and border, this way is much simplier.
|
|
// (4) it was not to steal focus from the application when displayed.
|
|
// User Win32 ShowWindow API with SW_SHOWNOACTIVATE
|
|
// In addition, this form should only for display and therefore should act as transparent, otherwise
|
|
// WindowFromPoint will return this form, instead of the control beneath. Need BOTH of the following to
|
|
// achieve this (don't know why, spent hours to try it out :( ):
|
|
// 1. Enabled = false;
|
|
// 2. WM_NCHITTEST returns HTTRANSPARENT
|
|
internal class DragForm : Form
|
|
{
|
|
public DragForm()
|
|
{
|
|
FormBorderStyle = FormBorderStyle.None;
|
|
ShowInTaskbar = false;
|
|
SetStyle(ControlStyles.Selectable, false);
|
|
Enabled = false;
|
|
}
|
|
|
|
protected override CreateParams CreateParams
|
|
{
|
|
get
|
|
{
|
|
CreateParams createParams = base.CreateParams;
|
|
createParams.ExStyle |= (int)Win32.WindowExStyles.WS_EX_TOOLWINDOW;
|
|
return createParams;
|
|
}
|
|
}
|
|
|
|
protected override void WndProc(ref Message m)
|
|
{
|
|
if (m.Msg == (int)Win32.Msgs.WM_NCHITTEST)
|
|
{
|
|
m.Result = (IntPtr)Win32.HitTest.HTTRANSPARENT;
|
|
return;
|
|
}
|
|
|
|
base.WndProc (ref m);
|
|
}
|
|
|
|
public virtual void Show(bool bActivate)
|
|
{
|
|
if (bActivate)
|
|
Show();
|
|
else
|
|
NativeMethods.ShowWindow(Handle, (int)Win32.ShowWindowStyles.SW_SHOWNOACTIVATE);
|
|
}
|
|
}
|
|
}
|