我想绘制大量的形状(线条,椭圆和......),然后将它们保存为位图或png。我制作了图纸,问题是:如何在C#中将 DrawingImage 转换为 BitmapImage ?代码是这样的:
DrawingGroup drawingGroup = new DrawingGroup();
using(DrawingContext context = drawingGroup.Open())
{
//make some drawing
}
DrawingImage drawingImage = new DrawingImage(drawingGroup)
// your suggestion? DrawingImage - > BitmapImage
答案 0 :(得分:6)
您可以将ImageDrawing放入Image控件并将其呈现为RenderTargetBitmap,这是一个BitmapSource,因此可以通过BitmapEncoder(本例中为PngBitmapEncoder)进行序列化。
public void SaveDrawingToFile(Drawing drawing, string fileName, double scale)
{
var drawingImage = new Image { Source = new DrawingImage(drawing) };
var width = drawing.Bounds.Width * scale;
var height = drawing.Bounds.Height * scale;
drawingImage.Arrange(new Rect(0, 0, width, height));
var bitmap = new RenderTargetBitmap((int)width, (int)height, 96, 96, PixelFormats.Pbgra32);
bitmap.Render(drawingImage);
var encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmap));
using (var stream = new FileStream(fileName, FileMode.Create))
{
encoder.Save(stream);
}
}
请注意,实际上并不需要BitmapImage进行编码,因为BitmapSource(或RenderTargetBitmap等任何派生类)将被接受为BitmapFrame.Create的参数。
稍微不同的解决方案将涉及DrawingVisual而不是DrawingImage:
public void SaveDrawingToFile(Drawing drawing, string fileName, double scale)
{
var drawingVisual = new DrawingVisual();
using (var drawingContext = drawingVisual.RenderOpen())
{
drawingContext.PushTransform(new ScaleTransform(scale, scale));
drawingContext.PushTransform(new TranslateTransform(-drawing.Bounds.X, -drawing.Bounds.Y));
drawingContext.DrawDrawing(drawing);
}
var width = drawing.Bounds.Width * scale;
var height = drawing.Bounds.Height * scale;
var bitmap = new RenderTargetBitmap((int)width, (int)height, 96, 96, PixelFormats.Pbgra32);
bitmap.Render(drawingVisual);
var encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmap));
using (var stream = new FileStream(fileName, FileMode.Create))
{
encoder.Save(stream);
}
}
答案 1 :(得分:0)
我发现这样很简单:
public static BitmapSource ToBitmapSource(DrawingImage source)
{
DrawingVisual drawingVisual = new DrawingVisual();
DrawingContext drawingContext = drawingVisual.RenderOpen();
drawingContext.DrawImage(source, new Rect(new Point(0, 0), new Size(source.Width, source.Height)));
drawingContext.Close();
RenderTargetBitmap bmp = new RenderTargetBitmap((int)source.Width, (int)source.Height, 96, 96, PixelFormats.Pbgra32);
bmp.Render(drawingVisual);
return bmp;
}
您可以使用它来获取System.Drawing.Bitmap
using (MemoryStream ms = new MemoryStream())
{
PngBitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(ToBitmapSource(drawingImage)));
encoder.Save(ms);
using (System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(ms))
{
bmpOut = new System.Drawing.Bitmap(bmp);
}
}