Android(安卓)Bitmap 透明度(Picture 透明度)

Android可透过 Paint 物件,来设定Bitmap透明度.

Java 程式范例 :

public class helloWorld extends Activity {    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView( new drawCanvas(this) );    }     class drawCanvas extends View {        public drawCanvas(Context context) {            super(context);        }         @Override        protected void onDraw(Canvas canvas) {            super.onDraw(canvas);             // 取得Resource 图片的Bitmap            Bitmap vBitmap = BitmapFactory.decodeResource( this.getResources()                                                         , R.drawable.icon                                                         );             // 建立Paint 物件            Paint vPaint = new Paint();            vPaint .setStyle( Paint.Style.STROKE );   //空心            vPaint .setAlpha( 75 );   // Bitmap透明度(0 ~ 100)             canvas.drawBitmap ( vBitmap , 50, 100, null );  //无透明            canvas.drawBitmap ( vBitmap , 50, 200, vPaint );  //有透明        }    }}

转自：http://disanji.net/2010/12/11/android-bitmap-picture/

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