SweepGradient扫描渲染

import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Shader;import android.graphics.SweepGradient;import android.view.View;/** * @version 2012-8-14 上午10:45:28 **/public class SweepGameView extends View implements Runnable {    Paint mPaint = null;    // 梯度渲染    Shader mSweepGradient = null;    public SweepGameView(Context context) {        super(context);        // 创建SweepGradient对象        // 第一个,第二个参数中心坐标        // 后面的参数与线性渲染相同        mSweepGradient = new SweepGradient(150, 150, new int[] { Color.GREEN,                Color.RED, Color.BLUE, Color.WHITE }, null);        mPaint = new Paint();        new Thread(this).start();    }    @Override    protected void onDraw(Canvas canvas) {        // 绘制梯度渐变        mPaint.setShader(mSweepGradient);        // 这里可以话任意形状        canvas.drawRect(0, 0, 300, 300, mPaint);    }    @Override    public void run() {        while(!Thread.currentThread().isInterrupted()) {            try {                Thread.sleep(100);            }            catch(Exception e) {                Thread.currentThread().interrupt();            }            postInvalidate();        }    }}