Android image superposition effect-two methods

:

First:

Second:

 

The first is the effect drawn through canvas:

Public void first (View v) {// prevents Immutable bitmap passed to Canvas constructor errors Bitmap bitmap1 = BitmapFactory. decodeResource (getResources (), R. drawable. apple ). copy (Bitmap. config. ARGB_8888, true); Bitmap bitmap2 = (BitmapDrawable) getResources (). getDrawable (R. drawable. go )). getBitmap (); Bitmap newBitmap = null; newBitmap = Bitmap. createBitmap (bitmap1); Canvas canvas = new Canvas (newBitmap); Paint paint = new Paint (); int w = bitmap1.getWidth (); int h = bitmap1.getHeight (); int w_2 = bitmap2.getWidth (); int H2 = bitmap2.getHeight (); paint. setColor (Color. GRAY); paint. setAlpha (1, 125); canvas. drawRect (0, 0, bitmap1.getWidth (), bitmap1.getHeight (), paint); paint = new Paint (); canvas. drawBitmap (bitmap2, Math. abs (w-w_2)/2, Math. abs (h-H2)/2, paint); canvas. save (Canvas. ALL_SAVE_FLAG); // stores the newly merged image canvas. restore (); image. setImageBitmap (newBitmap );}

 

Canvas canvas = new Canvas (newBitmap); when creating a Canvas using newBitmap, all operations are implemented on this graph.

In this example, the player starts playing the video. Calculate the intermediate position, overwrite a transparent Gray Square, and draw a playback button in the middle.

 

The second type is the system LayerDrawable class, which is mainly used to control the combination of multiple images:

 

Public void second (View v) {Bitmap bitmap1 = (BitmapDrawable) getResources (). getDrawable (R. drawable. apple )). getBitmap (); Bitmap bitmap2 = (BitmapDrawable) getResources (). getDrawable (R. drawable. go )). getBitmap (); Drawable [] array = new Drawable [2]; array [0] = new BitmapDrawable (bitmap1); array [1] = new BitmapDrawable (bitmap2 ); layerDrawable la = new LayerDrawable (array); // The first parameter is the layer index number, and the following four parameters are left, top, right, and bottom la. setLayerInset (0, 0, 0, 0, 0); la. setLayerInset (1, 20, 20, 20, 20); image. setImageDrawable (la );}

Associate array to control the position of each layer

 

Note: The above prevents Immutable bitmap passed to Canvas constructor errors.

The reason is that if you do not use the copy method, direct reference will modify the resource file, while android does not allow you to modify the images in the res file in the code.

I don't know why I spent an hour testing code and writing this article, maybe for future data viewing, maybe for verifying the effect in my own mind, maybe because my mind suddenly becomes dull, I am listening to four season in one day.

Code: http://files.cnblogs.com/not-code/picture_overlay.zip

Address: http://www.cnblogs.com/not-code/archive/2011/08/18/2145126.html

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