windows-mobile - Compact Framework：用椭圆绘制多行字符串

Question

我正在为 Windows Mobile 应用程序创建从 ListView 继承的所有者绘制控件。我Graphics.DrawString用来写出两行文本字符串（使用.NET CF 3.5）。问题是某些项目的文本特别长，不适合两行。谷歌搜索找到了使用MeasureString和手动截断我的字符串的方法，但这仅适用于单行字符串。有什么办法可以在这里得到省略号，还是我必须接受剪切的文本或重新设计以仅使用一行？（两者都不是交易破坏者，但省略号肯定会很好。）

Answer 1

是的，您可以显示省略号，但您必须执行一些 P/Invoking（有什么新功能？）：

public static void DrawText(Graphics gfx, string text, Font font, Color color, int x, int y, int width, int height)
{
 IntPtr hdcTemp = IntPtr.Zero;
 IntPtr oldFont = IntPtr.Zero;
 IntPtr currentFont = IntPtr.Zero;

 try
 {
  hdcTemp = gfx.GetHdc();
  if (hdcTemp != IntPtr.Zero)
  {
   currentFont = font.ToHfont();
   oldFont = NativeMethods.SelectObject(hdcTemp, currentFont);

   NativeMethods.RECT rect = new NativeMethods.RECT();
   rect.left = x;
   rect.top = y;
   rect.right = x + width;
   rect.bottom = y + height;

   int colorRef = color.R | (color.G << 8) | (color.B << 16);
   NativeMethods.SetTextColor(hdcTemp, colorRef);

   NativeMethods.DrawText(hdcTemp, text, text.Length, ref rect, NativeMethods.DT_END_ELLIPSIS | NativeMethods.DT_NOPREFIX);
  }
 }
 finally
 {
  if (oldFont != IntPtr.Zero)
  {
   NativeMethods.SelectObject(hdcTemp, oldFont);
  }

  if (hdcTemp != IntPtr.Zero)
  {
   gfx.ReleaseHdc(hdcTemp);
  }

  if (currentFont != IntPtr.Zero)
  {
   NativeMethods.DeleteObject(currentFont);
  }
 }
}

NativeMethods 是一个包含我所有本机调用的类。包含：

internal const int DT_END_ELLIPSIS = 32768;
internal const int DT_NOPREFIX = 2048;


[DllImport("coredll.dll", SetLastError = true)]
internal static extern int DrawText(IntPtr hDC, string Text, int nLen, ref RECT pRect, uint uFormat);

[DllImport("coredll.dll", SetLastError = true)]
internal static extern int SetTextColor(IntPtr hdc, int crColor);

[DllImport("coredll.dll", SetLastError = true)]
internal static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);

[DllImport("coredll.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool DeleteObject(IntPtr hObject);

[StructLayout(LayoutKind.Sequential)]
internal struct RECT
{
 public int left;
 public int top;
 public int right;
 public int bottom;

}