从这里:
当您使用 Save 方法将图形图像保存为 Windows 图元文件格式 (WMF) 或增强的图元文件格式 (EMF) 文件时,生成的文件将保存为可移植网络图形 (PNG) 文件。出现此问题的原因是 .NET Framework 的 GDI+ 组件没有可用于将文件另存为 .wmf 或 .emf 文件的编码器。
但我猜你已经走到了那一步:)
这里有人将位图放入 FileStream 中。
metafileStream = MakeMetafileStream(gdiBitmap);
MakeMetafileStream() 是:
private static MemoryStream MakeMetafileStream(Bitmap image)
{
Graphics graphics = null;
Metafile metafile= null;
var stream = new MemoryStream();
try
{
using (graphics = Graphics.FromImage(image))
{
var hdc = graphics.GetHdc();
metafile= new Metafile(stream, hdc);
graphics.ReleaseHdc(hdc);
}
using (graphics = Graphics.FromImage(metafile))
{ graphics.DrawImage(image, 0, 0); }
}
finally
{
if (graphics != null)
{ graphics.Dispose(); }
if (metafile!= null)
{ metafile.Dispose(); }
}
return stream;
}
有趣的东西。但至于编码器的事情......
在这里,来自 MS 的 Peter Huang 发布了这种非托管方法:
[DllImport("gdiplus.dll")]
private static extern uint GdipEmfToWmfBits (IntPtr _hEmf, uint _bufferSize,
byte[] _buffer, int _mappingMode, EmfToWmfBitsFlags _flags);
[DllImport("gdi32.dll")]
private static extern IntPtr SetMetaFileBitsEx (uint _bufferSize,
byte[] _buffer);
[DllImport("gdi32.dll")]
private static extern IntPtr CopyMetaFile (IntPtr hWmf,
string filename);
[DllImport("gdi32.dll")]
private static extern bool DeleteMetaFile (IntPtr hWmf);
[DllImport("gdi32.dll")]
private static extern bool DeleteEnhMetaFile (IntPtr hEmf);
private void button4_Click(object sender, System.EventArgs e)
{
Graphics g= this.CreateGraphics();
IntPtr hDC = g.GetHdc();
Metafile mf = new Metafile(hDC,EmfType.EmfOnly);
g.ReleaseHdc(hDC);
g.Dispose();
g=Graphics.FromImage(mf);
//Pen p = new Pen(Color.White,5);
g.DrawArc(Pens.Black,0,0,200,200,0,360);
//g.DrawImage(Bitmap.FromFile(@"c:\temp\test.bmp"),0,0);
g.Dispose();
IntPtr _hEmf= mf.GetHenhmetafile();
uint _bufferSize = GdipEmfToWmfBits(_hEmf, 0, null, MM_ANISOTROPIC,
EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
byte[] _buffer = new byte[_bufferSize];
GdipEmfToWmfBits(_hEmf, _bufferSize, _buffer, MM_ANISOTROPIC,
EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
IntPtr hmf = SetMetaFileBitsEx(_bufferSize, _buffer);
CopyMetaFile(hmf, "C:\\ConvertedMetafile.wmf");
DeleteMetaFile(hmf);
DeleteEnhMetaFile(_hEmf);
}
希望这会让你到达那里:)