如何設置Winform控件的ClientRectangle
最近學習制作WinForm控件，自己動手寫控件的時候才發現System.Windows.Forms.Control 竟然沒有提供默認的border繪制。記得以前用API做控件的時候，只需要設置空間窗口的WS_BORDER 風格就可以。遍尋無方，只有自己繪制了，這里有出現一個，如果border在客戶區，那么在OnPaint方法里不得不每次都要考慮Border所占用的區域，而且，如果從這個類派生的話，將無法獲得準確的客戶區。
現在要解決的問題就是如何重新設置客戶區的矩形區域的尺寸，查看了一下Control類的ClientRectangle屬性：
public Rectangle ClientRectangle { get; }是個只讀屬性，看來是不能通過這個屬性達到目的了。再查找Control類的文檔，也沒有這方面的說明，沒有辦法，只能用API搞定了。可以通過計算非客戶區尺寸來設置客戶區尺寸，Border在非客戶繪制。下面就是主要的代碼，就是通過重載WndProc方法，捕捉WM_NCCALCSIZE消息，實現自己的邏輯。
![]()
protected override void WndProc(ref Message m)
![]()
{
![]()
switch (m.Msg)
![]()
{
![]()
case (int)WinAPI_WM.WM_NCCALCSIZE:
![]()
if (m.WParam.ToInt32() == 0)
![]()
{
![]()
WinAPI_RECT rc = (WinAPI_RECT)m.GetLParam(typeof(WinAPI_RECT));
![]()
rc.Left += 1;
![]()
rc.Top += 1;
![]()
rc.Right -= 1;
![]()
rc.Bottom -= 1;
![]()
Marshal.StructureToPtr(rc, m.LParam, true);
![]()
m.Result = IntPtr.Zero;
![]()
}
![]()
else
![]()
{
![]()
WinAPI_NCCALCSIZE_PARAMS csp;
![]()
csp = (WinAPI_NCCALCSIZE_PARAMS)m.GetLParam(typeof(WinAPI_NCCALCSIZE_PARAMS));
![]()
csp.rgrc0.Top += 1;
![]()
csp.rgrc0.Bottom -= 1;
![]()
csp.rgrc0.Left += 1;
![]()
csp.rgrc0.Right -= 1;
![]()
![]()
Marshal.StructureToPtr(csp, m.LParam, true);
![]()
//Return zero to preserve client rectangle
![]()
m.Result = IntPtr.Zero;
![]()
}
![]()
break;
![]()
case (int)WinAPI_WM.WM_NCPAINT:
![]()
{
![]()
m.WParam = NCPaint(m.WParam);
![]()
break;
![]()
}
![]()
}
![]()
![]()
base.WndProc(ref m);
![]()
}
![]()
![]()
public IntPtr NCPaint(IntPtr region)
![]()
{
![]()
IntPtr hDC = GetWindowDC(this.Handle);
![]()
if (hDC != IntPtr.Zero)
![]()
{
![]()
Graphics grTemp = Graphics.FromHdc(hDC);
![]()
![]()
int ScrollBarWidth = SystemInformation.VerticalScrollBarWidth;
![]()
int ScrollBarHeight = SystemInformation.HorizontalScrollBarHeight;
![]()
![]()
WINDOWINFO wi = new WINDOWINFO();
![]()
wi.cbSize = (uint)Marshal.SizeOf(wi);
![]()
![]()
//得到當前控件的窗口信息
![]()
GetWindowInfo(Handle, ref wi);
![]()
![]()
wi.rcClient.Right--;
![]()
wi.rcClient.Bottom--;
![]()
![]()
![]()
//獲得當前控件的區域
![]()
Region UpdateRegion = new Region(new Rectangle(wi.rcWindow.Top,wi.rcWindow.Left,wi.rcWindow.Right-wi.rcWindow.Left,wi.rcWindow.Bottom-wi.rcWindow.Top));
![]()
![]()
//獲得客戶區以外的區域
![]()
UpdateRegion.Exclude(new Rectangle(wi.rcClient.Top, wi.rcClient.Left, wi.rcClient.Right - wi.rcClient.Left, wi.rcClient.Bottom - wi.rcClient.Top));
![]()
![]()
if (IsHScrollVisible && IsVScrollVisible)
![]()
{
![]()
UpdateRegion.Exclude(Rectangle.FromLTRB
![]()
(wi.rcClient.Right + 1, wi.rcClient.Bottom + 1,
![]()
wi.rcWindow.Right, wi.rcWindow.Bottom));
![]()
}
![]()
![]()
//得到當前區域的句柄
![]()
IntPtr hRgn = UpdateRegion.GetHrgn(grTemp);
![]()
![]()
//For Painting we need to zero offset the Rectangles.
![]()
Rectangle WindowRect = new Rectangle(wi.rcWindow.Top, wi.rcWindow.Left, wi.rcWindow.Right - wi.rcWindow.Left, wi.rcWindow.Bottom - wi.rcWindow.Top);
![]()
![]()
Point offset = Point.Empty - (Size)WindowRect.Location;
![]()
![]()
WindowRect.Offset(offset);
![]()
![]()
Rectangle ClientRect = WindowRect;
![]()
![]()
ClientRect.Inflate(-1, -1);
![]()
![]()
//Fill the BorderArea
![]()
Region PaintRegion = new Region(WindowRect);
![]()
PaintRegion.Exclude(ClientRect);
![]()
grTemp.FillRegion(SystemBrushes.Control, PaintRegion);
![]()
![]()
//Fill the Area between the scrollbars
![]()
if (IsHScrollVisible && IsVScrollVisible)
![]()
{
![]()
Rectangle ScrollRect = new Rectangle(ClientRect.Right - ScrollBarWidth,
![]()
ClientRect.Bottom - ScrollBarHeight, ScrollBarWidth + 2, ScrollBarHeight + 2);
![]()
ScrollRect.Offset(-1, -1);
![]()
grTemp.FillRectangle(SystemBrushes.Control, ScrollRect);
![]()
}
![]()
![]()
//Adjust ClientRect for Drawing Border.
![]()
ClientRect.Inflate(2, 2);
![]()
ClientRect.Width--;
![]()
ClientRect.Height--;
![]()
![]()
//Draw Outer Raised Border
![]()
ControlPaint.DrawBorder3D(grTemp, WindowRect, Border3DStyle.Raised,
![]()
Border3DSide.Bottom | Border3DSide.Left | Border3DSide.Right | Border3DSide.Top);
![]()
![]()
//Draw Inner Sunken Border
![]()
ControlPaint.DrawBorder3D(grTemp, ClientRect, Border3DStyle.Sunken,
![]()
Border3DSide.Bottom | Border3DSide.Left | Border3DSide.Right | Border3DSide.Top);
![]()
![]()
ReleaseDC(Handle, hDC);
![]()
![]()
grTemp.Dispose();
![]()
![]()
return hRgn;
![]()
![]()
}
![]()
![]()
RefreshScrollBar();
![]()
return region;
![]()
}
![]()
現在要解決的問題就是如何重新設置客戶區的矩形區域的尺寸，查看了一下Control類的ClientRectangle屬性：
public Rectangle ClientRectangle { get; }是個只讀屬性，看來是不能通過這個屬性達到目的了。再查找Control類的文檔，也沒有這方面的說明，沒有辦法，只能用API搞定了。可以通過計算非客戶區尺寸來設置客戶區尺寸，Border在非客戶繪制。下面就是主要的代碼，就是通過重載WndProc方法，捕捉WM_NCCALCSIZE消息，實現自己的邏輯。
protected override void WndProc(ref Message m)
{
switch (m.Msg)
{
case (int)WinAPI_WM.WM_NCCALCSIZE:if (m.WParam.ToInt32() == 0){WinAPI_RECT rc = (WinAPI_RECT)m.GetLParam(typeof(WinAPI_RECT));rc.Left += 1;rc.Top += 1; rc.Right -= 1; rc.Bottom -= 1;Marshal.StructureToPtr(rc, m.LParam, true);m.Result = IntPtr.Zero;
}else{WinAPI_NCCALCSIZE_PARAMS csp;csp = (WinAPI_NCCALCSIZE_PARAMS)m.GetLParam(typeof(WinAPI_NCCALCSIZE_PARAMS));csp.rgrc0.Top += 1; csp.rgrc0.Bottom -= 1;csp.rgrc0.Left += 1; csp.rgrc0.Right -= 1;Marshal.StructureToPtr(csp, m.LParam, true);//Return zero to preserve client rectanglem.Result = IntPtr.Zero;}break;case (int)WinAPI_WM.WM_NCPAINT:{m.WParam = NCPaint(m.WParam);break;}}base.WndProc(ref m);
}public IntPtr NCPaint(IntPtr region){IntPtr hDC = GetWindowDC(this.Handle);if (hDC != IntPtr.Zero){Graphics grTemp = Graphics.FromHdc(hDC);int ScrollBarWidth = SystemInformation.VerticalScrollBarWidth;int ScrollBarHeight = SystemInformation.HorizontalScrollBarHeight;WINDOWINFO wi = new WINDOWINFO();wi.cbSize = (uint)Marshal.SizeOf(wi);//得到當前控件的窗口信息GetWindowInfo(Handle, ref wi);wi.rcClient.Right--;wi.rcClient.Bottom--;//獲得當前控件的區域Region UpdateRegion = new Region(new Rectangle(wi.rcWindow.Top,wi.rcWindow.Left,wi.rcWindow.Right-wi.rcWindow.Left,wi.rcWindow.Bottom-wi.rcWindow.Top));//獲得客戶區以外的區域UpdateRegion.Exclude(new Rectangle(wi.rcClient.Top, wi.rcClient.Left, wi.rcClient.Right - wi.rcClient.Left, wi.rcClient.Bottom - wi.rcClient.Top));if (IsHScrollVisible && IsVScrollVisible){UpdateRegion.Exclude(Rectangle.FromLTRB(wi.rcClient.Right + 1, wi.rcClient.Bottom + 1,wi.rcWindow.Right, wi.rcWindow.Bottom));}//得到當前區域的句柄IntPtr hRgn = UpdateRegion.GetHrgn(grTemp);//For Painting we need to zero offset the Rectangles.Rectangle WindowRect = new Rectangle(wi.rcWindow.Top, wi.rcWindow.Left, wi.rcWindow.Right - wi.rcWindow.Left, wi.rcWindow.Bottom - wi.rcWindow.Top);Point offset = Point.Empty - (Size)WindowRect.Location;WindowRect.Offset(offset);Rectangle ClientRect = WindowRect;ClientRect.Inflate(-1, -1);//Fill the BorderAreaRegion PaintRegion = new Region(WindowRect);PaintRegion.Exclude(ClientRect);grTemp.FillRegion(SystemBrushes.Control, PaintRegion);//Fill the Area between the scrollbarsif (IsHScrollVisible && IsVScrollVisible){Rectangle ScrollRect = new Rectangle(ClientRect.Right - ScrollBarWidth,ClientRect.Bottom - ScrollBarHeight, ScrollBarWidth + 2, ScrollBarHeight + 2);ScrollRect.Offset(-1, -1);grTemp.FillRectangle(SystemBrushes.Control, ScrollRect);}//Adjust ClientRect for Drawing Border.ClientRect.Inflate(2, 2);ClientRect.Width--;ClientRect.Height--;//Draw Outer Raised BorderControlPaint.DrawBorder3D(grTemp, WindowRect, Border3DStyle.Raised,Border3DSide.Bottom | Border3DSide.Left | Border3DSide.Right | Border3DSide.Top);//Draw Inner Sunken BorderControlPaint.DrawBorder3D(grTemp, ClientRect, Border3DStyle.Sunken,Border3DSide.Bottom | Border3DSide.Left | Border3DSide.Right | Border3DSide.Top);ReleaseDC(Handle, hDC);grTemp.Dispose();return hRgn;}RefreshScrollBar();return region;}
浙公網安備 33010602011771號