android 笔记 --- Android Shadow 阴影制作

在Android View 中, 要制作阴影,

可以利用 Paint 物件的 setShadowLayer 函数.

Java 程式码范例 :

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);
 
            // 建立Paint 物件
            Paint vPaint = new Paint();
            Paint vPaint2 = new Paint();
 
            // --------------------------------------------
            // 设定颜色
            vPaint.setColor(0xFFFFFF00);
 
            // 实心矩形
            canvas.drawRect( 30
                           , 50
                           , 130
                           , 150
                           , vPaint
                           );
 
            // 设定阴影(柔边, X 轴位移, Y 轴位移, 阴影颜色)
            vPaint .setShadowLayer (5, 3, 3, 0xFFFF00FF);
 
            // 实心矩形& 其阴影
            canvas.drawRect( 30
                           , 200
                           , 130
                           , 300
                           , vPaint
                           );
 
            // --------------------------------------------
            // 设定颜色
            vPaint2.setColor(0xFFFFFF00);
 
            // 空心
            vPaint2 .setStyle(Style.STROKE);
 
            // 空心矩形
            canvas.drawRect( 200
                           , 50
                           , 300
                           , 150
                           , vPaint2
                           );
 
            // 设定阴影(柔边, X 轴位移, Y 轴位移, 阴影颜色)
            vPaint2 .setShadowLayer (5, 3, 3, 0xFFFF00FF);
 
            // 空心矩形& 其阴影
            canvas.drawRect( 200
                           , 200
                           , 300
                           , 300
                           , vPaint2
                           );
        }
    }
}