下面的代码将使用“拖动时显示窗口内容”的系统设置来重新定位窗口,同时将其暂时设置为关闭,同时调整窗口大小,然后将其设置回系统设置。
这使您可以在 Windows 窗体中实现无闪烁的窗体大小调整。
由于此属性是修改 HKEY_CURRENT_USER\Control Panel\Desktop\DragFullWindows 注册表项的用户设置,因此它不需要管理员权限。
[DllImport("user32.dll", EntryPoint = "SystemParametersInfo", CharSet = CharSet.Auto)]
public static extern int GetSystemParametersInfo(int uAction, int uParam, out int lpvParam, int fuWinIni);
[DllImport("user32.dll", EntryPoint = "SystemParametersInfo", CharSet = CharSet.Auto)]
public static extern int SetSystemParametersInfo(int uAction, int uParam, int lpvParam, int fuWinIni);
private const int SPI_GETDRAGFULLWINDOWS = 38;
private const int SPI_SETDRAGFULLWINDOWS = 37;
private const int WM_SYSCOMMAND = 0x0112;
private const int SC_SIZE = 0xF000;
//change 'Show window content while dragging' to false while resizing
protected override void WndProc(ref Message m)
{
if (m.Msg == WM_SYSCOMMAND && (m.WParam.ToInt32() & 0xfff0) == SC_SIZE)
{
int isDragFullWindow;
GetSystemParametersInfo(SPI_GETDRAGFULLWINDOWS, 0, out isDragFullWindow, 0);
if (isDragFullWindow != 0)
SetSystemParametersInfo(SPI_SETDRAGFULLWINDOWS, 0, 0, 0);
base.WndProc(ref m);
if (isDragFullWindow != 0)
SetSystemParametersInfo(SPI_SETDRAGFULLWINDOWS, 1, 0, 0);
}
else
{
base.WndProc(ref m);
}
}
//reduce control flickering and black stripes when window is resized
protected override CreateParams CreateParams
{
get
{
CreateParams cp = base.CreateParams;
cp.ExStyle |= 0x02000000; // Turn on WS_EX_COMPOSITED
return cp;
}
}