WPF以任意角度旋转并返回BitmapSource

using System;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;

public BitmapSource RotateImage(BitmapSource source, double angle)
{
    // 创建一个TransformGroup来包含旋转变换
    TransformGroup transformGroup = new TransformGroup();
    transformGroup.Children.Add(new RotateTransform(angle));

    // 创建一个DrawingVisual对象来绘制图像
    DrawingVisual drawingVisual = new DrawingVisual();
    using (DrawingContext drawingContext = drawingVisual.RenderOpen())
    {
        // 应用旋转变换并绘制图像
        drawingContext.PushTransform(transformGroup);
        drawingContext.DrawImage(source, new Rect(0, 0, source.Width, source.Height));
        drawingContext.Pop();
    }

    // 创建一个RenderTargetBitmap对象来保存绘制结果
    RenderTargetBitmap targetBitmap = new RenderTargetBitmap(
        (int)source.Width, (int)source.Height, 96, 96, PixelFormats.Default);
    targetBitmap.Render(drawingVisual);

    return targetBitmap;
}