silverlight中怎么实现两张图片拼接问题

在深蓝色的教程中有真么个方法是在wpf中使用的
/// <summary>

/// 拼装角色+装备后切割成系列帧图片并保存进内存(装备角色)

/// </summary>

/// <param name="Equipment">装备代号数组</param>

/// <param name="rowNum">帧合成图行数</param>

/// <param name="colNum">帧合成图列数</param>

/// <param name="totalWidth">帧图合成后总宽</param>

/// <param name="totalHeight">帧图合成后总高</param>

/// <param name="singleWidth">单帧图宽</param>

/// <param name="singleHeight">单帧图高</param>

/// <returns>如果缓存中有则读取缓存，否则返回合成的图片源</returns>

public static BitmapSource[,] EquipPart(int[] Equipment, int rowNum, int colNum, int totalWidth, int totalHeight, int singleWidth, int singleHeight) {

//Equipment[0]为衣服代号，Equipment[1]为武器代号，本例中装备只由衣服+武器组成

//假如内存中没有该装备的角色现成图片源则进行读取

if (PartImage[Equipment[0], Equipment[1]] == null) {

BitmapSource[,] bitmap = new BitmapSource[rowNum, colNum];

//加载角色衣服(身体)大图

BitmapSource bitmapSource = new BitmapImage(new Uri(@"Images\Body" + Equipment[0].ToString() + ".gif", UriKind.Relative));

//假如武器不是0，即如果角色手上有武器而非空手

if (Equipment[1] != 0) {

//加载武器大图，并与衣服大图组装

BitmapSource bitmapSource1 = new BitmapImage(new Uri(@"Images\Weapon" + Equipment[1].ToString() + ".gif", UriKind.Relative));

DrawingVisual drawingVisual = new DrawingVisual();

Rect rect = new Rect(0, 0, totalWidth, totalHeight);

DrawingContext drawingContext = drawingVisual.RenderOpen();

drawingContext.DrawImage(bitmapSource, rect);

drawingContext.DrawImage(bitmapSource1, rect);

drawingContext.Close();

RenderTargetBitmap renderTargetBitmap = new RenderTargetBitmap(totalWidth, totalHeight, 0, 0, PixelFormats.Pbgra32);

renderTargetBitmap.Render(drawingVisual);

bitmapSource = renderTargetBitmap;

//降低图片质量以提高系统性能(由于本身图片已经为低质量的gif类型，因此效果不大)

//RenderOptions.SetBitmapScalingMode(bitmapSource, BitmapScalingMode.LowQuality);

}

for (int i = 0; i < rowNum; i++) {

for (int j = 0; j < colNum; j++) {

bitmap[i, j] = new CroppedBitmap(bitmapSource, new Int32Rect(j * singleWidth, i * singleHeight, singleWidth, singleHeight));

}

}

//将装备合成图放进内存

PartImage[Equipment[0], Equipment[1]] = bitmap;

return bitmap;

} else {

//如果内存中已存在该装备的角色图片源则从内存中返回合成图，极大提高性能

return PartImage[Equipment[0], Equipment[1]];

}

}

不知在SL中怎么实现同样的功能