DragForm.cs
上传用户:szlfmled
上传日期:2020-11-22
资源大小:978k
文件大小:2k
- using System;
- using System.Windows.Forms;
- namespace WeifenLuo.WinFormsUI.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);
- }
- }
- }