Android Foreground rendering pictures

Android foreground rendering, mainly rewrite the view OnDraw method, in the canvas operation

Custom MyView Class

 PackageCom.ssln;ImportAndroid.annotation.SuppressLint;ImportAndroid.content.Context;ImportAndroid.graphics.Bitmap;Importandroid.graphics.BitmapFactory;ImportAndroid.graphics.Canvas;ImportAndroid.graphics.Color;ImportAndroid.graphics.Matrix;ImportAndroid.graphics.Paint;ImportAndroid.util.AttributeSet;ImportAndroid.view.View; Public classMyViewextendsView {PrivateBitmap Bitmap;//Image    PrivatePaint paint;//Brushes     PublicMyView (Context context, AttributeSet attrs) {Super(context, attrs);    Initbitmap (); }    /*** Initialization Information*/     Public voidInitbitmap () {//Instantiate a brushPaint=NewPaint (); //Load from Resourcebitmap=Bitmapfactory.decoderesource (Getresources (), r.drawable.img); } @SuppressLint ("Drawallocation") @Overrideprotected voidOnDraw (canvas canvas) {Super. OnDraw (canvas); Paint.setantialias (true);//turn on anti-aliasingPaint.setcolor (Color.Black);//Set Brush ColorPaint.settextscalex (15);//Set Text SizeCanvas.drawbitmap (bitmap, 10,10, paint);//draw pictures in 10x10 's positionCanvas.save ();//Save Canvas StateMatrix M1=NewMatrix ();//MatrixM1.settranslate (500, 10);//Pan X500 Y10Matrix m2=NewMatrix (); M2.setrotate (15);//Rotate 15 °Matrix m3=NewMatrix ();            M3.setconcat (M1, M2); //merging matricesM1.setscale (0.8f, 0.8f);//set the zoom ratioM2.setconcat (M3, M1);//MergingCanvas.drawbitmap (Bitmap, M2, paint);//drawing, panning, rotating, zoomingCanvas.restore ();//Restore Canvas StateCanvas.save (); Paint.setalpha (180);//Set TransparencyM1.settranslate (200, 100); M2.setscale (1.3f, 1.3f);        M3.setconcat (M1, M2);  Canvas.drawbitmap (bitmap, m3, paint); //drawing, panning, zoomingPaint.reset ();//Reset BrushCanvas.restore (); Paint.settextsize (24);        Paint.setcolor (Color.Black); Canvas.drawtext ("Picture width:" +bitmap.getwidth (), 20,240, paint);//write the text, the width of the imageCanvas.drawtext ("Picture height:" +bitmap.getheight (), 20,270, paint);        Paint.reset (); } }

Modify Activity_main.xml

<Relativelayoutxmlns:android= "Http://schemas.android.com/apk/res/android"Xmlns:tools= "Http://schemas.android.com/tools"Android:layout_width= "Match_parent"Android:layout_height= "Match_parent"Android:paddingbottom= "@dimen/activity_vertical_margin"Android:paddingleft= "@dimen/activity_horizontal_margin"Android:paddingright= "@dimen/activity_horizontal_margin"Android:paddingtop= "@dimen/activity_vertical_margin"Tools:context= "Com.ssln.MainActivity" >    <Com.ssln.MyViewAndroid:layout_width= "Fill_parent"Android:layout_height= "Fill_parent"         /></Relativelayout>

Run the following effect

Android Foreground rendering pictures