C# 绘制窗体客户非客户区要用WM_PAINT和WM_NCPAINT

窗体分为两部分:客户区(Client area)和非客户区(Non-Client area) 
WM_PAINT消息、OnPaint()方法、GetDC()API函数都是处理窗体客户区绘制的 
  
而标题栏处于非客户区中,所以WM_PAINT消息、OnPaint()方法、GetDC()API函数都用不上 
  
GetWindowDC()是获得整个窗体的画布句柄(Device Context翻译为:设备清单,我习惯称为画布句柄),包括非客户区 
  
GDI的绘制都离不开DC,因为操作系统必须知道你要在什么地方绘制图形 
  
当其他窗体遮挡或者移开,系统都会重新绘制窗体。这时就会发出WM_PAINT和WM_NCPAINT消息通知窗体重绘界面。 
  
收到WM_NCPAINT消息(非客户区绘制消息)说明非客户区正需要重新绘制 
  
重载WndProc()方法(窗体消息处理过程),处理WM_NCPAINT等消息即可.... 
  
“基本的步骤” 就是:截获WM_NCPAINT消息、得到窗体完整画布句柄、在完整画布上绘制图形。 
    WM_NCPAINT WM_NCCALCSIZE WM_NCACTIVATE WM_NCHITTEST
建议楼主搜索关键词:“C# WM_NCPAINT WndProc Graphics”得到更多的参考资料 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

[DllImport   ( "User32.dll ")] 
  
private   static   extern   IntPtr   GetWindowDC(IntPtr   hwnd); 
  
[DllImport   ( "User32.dll ")] 
  
private   static   extern   int   ReleaseDC(IntPtr   hwnd,   IntPtr   hdc); 
  
[DllImport   ( "Kernel32.dll ")] 
  
private   static   extern   int   GetLastError(); 
  
//标题栏按钮的矩形区域。 
  
Rectangle   m_rect   =   new   Rectangle(205,   6,   20,   20); 
  
protected   override   void   WndProc(ref   Message   m) 
  
{ 
  
base.WndProc(ref   m); 
  
switch(m.Msg) 
  
{ 
  
case   0x86://WM_NCACTIVATE 
  
goto   case   0x85; 
  
case   0x85://WM_NCPAINT 
  
{ 
  
IntPtr   hDC   =   GetWindowDC(m.HWnd); 
  
//把DC转换为.NET的Graphics就可以很方便地使用Framework提供的绘图功能了 
  
Graphics   gs   =   Graphics.FromHdc(hDC); 
  
gs.FillRectangle(new   LinearGradientBrush(m_rect,   Color.Pink,   Color.Purple,   LinearGradientMode.BackwardDiagonal),   m_rect); 
  
StringFormat   strFmt   =   new   StringFormat(); 
  
strFmt.Alignment   =   StringAlignment.Center; 
  
strFmt.LineAlignment   =   StringAlignment.Center; 
  
gs.DrawString( "√ ",   this.Font,   Brushes.BlanchedAlmond,   m_rect,   strFmt); 
  
gs.Dispose(); 
  
//释放GDI资源 
  
ReleaseDC(m.HWnd,   hDC); 
  
break; 
  
} 
  
case   0xA1://WM_NCLBUTTONDOWN 
  
{ 
  
Point   mousePoint   =   new   Point((int)m.LParam); 
  
mousePoint.Offset(-this.Left,   -this.Top); 
  
if(m_rect.Contains(mousePoint)) 
  
{ 
  
MessageBox.Show( "hello "); 
  
} 
  
break; 
  
} 
  
} 
  
} 
  
//在窗口大小改变时及时更新按钮的区域。 
  
private   void   Form1_SizeChanged(object   sender,   System.EventArgs   e) 
  
{ 
  
m_rect.X   =   this.Bounds.Width   -   95; 
  
m_rect.Y   =   6; 
  
m_rect.Width   =   m_rect.Height   =   20; 
  
} 
  
} 
  
}

  

C# 绘制窗体客户非客户区要用WM_PAINT和WM_NCPAINT,布布扣,bubuko.com

C# 绘制窗体客户非客户区要用WM_PAINT和WM_NCPAINT

上一篇:Win32中GDI+应用(二)--初始化与清理


下一篇:Win32 GDI 非矩形区域剪裁,双缓冲技术