onOffsetsChanged: move Bitmap

问题:

i want my Bitmap that has the height of the screen and has a bigger width than the screen to be moved a little bit to the right or left if the user changes the desktop so he can see the entire image.

Here is my code that just works partially:

        int x = -1*(int)((xOffset*bmp.getWidth()));
        canvas.drawBitmap(bmp, x, 0, null);

thank you!

回答1:

You get exact pixel values via the variables xPixels and yPixels in onOffsetsChanged(). See my answer here: android live wallpaper rescaling

For example, in onOffsetsChanged(), you can set a private class variable

mPixels = xPixels;

Then, in your draw routine

holder = getSurfaceHolder();
c = holder.lockCanvas();
c.translate(mPixels, 0f);
// c.drawBitmap ... goes here :-)

Typically, you will want a bitmap twice the width of your screen, with your artwork centered in the middle. For example: 320 pixel width screen -> 640 pixel width bitmap with "center" from 160 to 480. mPixels will be 0 at the left most launcher screen (of 5), -160 at the center, and -320 at the rightmost screen.