将图像分成几块Silverlight Windows Phone

Question

I want to split an image into several smaller images using silverlight for windows phone 7.5.

First of all, i want to know if this is even possible (i had some unpleasant surprises with windows phone APIs lately), and if it is, just give me some example as i have been able to find exactly none.

Thank you for your help.

Answer 1

WriteableBitmapEx is compatible with Windows Phone and has a Crop method to do exactly that. You just need to do the math to figure out how wide/tall and X/Y coordinates to crop at.

//this creates the four quadrants of sourceBitmap as new bitmaps

int halfWidth = sourceBitmap.PixelWidth / 2;
int halfHeight = sourceBitmap.PixelHeight / 2;

WriteableBitmap topLeft = sourceBitmap.Crop(0, 0, halfWidth, halfHeight);
WriteableBitmap topRight = sourceBitmap.Crop(halfWidth, 0, halfWidth, halfHeight);
WriteableBitmap bottomLeft = sourceBitmap.Crop(0, halfHeight, halfWidth, halfHeight);
WriteableBitmap bottomRight = sourceBitmap.Crop(halfWidth, halfHeight, halfWidth, halfHeight);

I might be off by a pixel (didn't test) in my above example, but it should demonstrate the API.

Answer 2

You could combine your silverlight project with XNA and use spritebatch.Draw(). It has a parameter for source rectangle, which lets you draw a part from the image.

MSDN has some help for how to combining silverlight and XNA. http://msdn.microsoft.com/en-us/library/hh202938(v=vs.92).aspx

Answer 3

Combine ScaleTransform and TranslateTransform to render the correct section.

ScaleTransform (numXTiles,numYTiles)

Translate (xTileIndex / numXTiles, yTileIndex / numYTiles);

Place the ImageControl inside a Grid to do the clipping