C#圆角文本框

最简单的思路.... 

 
   
     
  private 
    
  void 
   Form_Load ( 
  object 
   sender, EventArgs e)
        { 
                 
  this 
  .textBox1.Region  
  = 
    
  new 
   Region (GetRoundRectPath( 
  new 
   RectangleF( 
  0 
  , 
  0 
  , 
  this 
  .textBox1.Width, 
  this 
  .textBox1.Height),10f)); 
       
        }

        
  // 
  适合调整参数radius... 
  
 
           
  public 
   GraphicsPath GetRoundRectPath (RectangleF rect,  
  float 
   radius)
        {
             
  return 
   GetRoundRectPath (rect.X, rect.Y, rect.Width, rect.Height, radius);
        }

         
  public 
   GraphicsPath GetRoundRectPath ( 
  float 
   X,  
  float 
   Y,  
  float 
   width,  
  float 
   height,  
  float 
   radius)
        {
            GraphicsPath path  
  = 
    
  new 
   GraphicsPath ();
            path.AddLine (X  
  + 
   radius, Y, (X  
  + 
   width)  
  - 
   (radius  
  * 
   2f), Y);
            path.AddArc ((X  
  + 
   width)  
  - 
   (radius  
  * 
   2f), Y, radius  
  * 
   2f, radius  
  * 
   2f, 270f, 90f);
            path.AddLine (( 
  float 
  )(X  
  + 
   width), ( 
  float 
  )(Y  
  + 
   radius), ( 
  float 
  )(X  
  + 
   width), ( 
  float 
  )((Y  
  + 
   height)  
  - 
   (radius  
  * 
   2f)));
            path.AddArc (( 
  float 
  )((X  
  + 
   width)  
  - 
   (radius  
  * 
   2f)), ( 
  float 
  )((Y  
  + 
   height)  
  - 
   (radius  
  * 
   2f)), ( 
  float 
  )(radius  
  * 
   2f), ( 
  float 
  )(radius  
  * 
   2f), 0f, 90f);
            path.AddLine (( 
  float 
  )((X  
  + 
   width)  
  - 
   (radius  
  * 
   2f)), ( 
  float 
  )(Y  
  + 
   height), ( 
  float 
  )(X  
  + 
   radius), ( 
  float 
  )(Y  
  + 
   height));
            path.AddArc (X, (Y  
  + 
   height)  
  - 
   (radius  
  * 
   2f), radius  
  * 
   2f, radius  
  * 
   2f, 90f, 90f);
            path.AddLine (X, (Y  
  + 
   height)  
  - 
   (radius  
  * 
   2f), X, Y  
  + 
   radius);
            path.AddArc (X, Y, radius  
  * 
   2f, radius  
  * 
   2f, 180f, 90f);
            path.CloseFigure ();
             
  return 
   path;
        }