本文实例讲述了Android编程简单实现雷达扫描效果。分享给大家供大家参考，具体如下：
在eoe看到有一篇关于雷达扫描的文章，然后看了下，很简单，但是觉得还有很多可以优化的地方，下面贴出来
package com.example.wave; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Matrix; import android.graphics.Paint; import android.graphics.Paint.Style; import android.graphics.Shader; import android.graphics.SweepGradient; import android.util.AttributeSet; import android.widget.FrameLayout; public class RadarView extends FrameLayout { private int viewSize = 500; private Paint mPaintLine; private Paint mPaintSector; private boolean isStart = false; private ScanThread mThread; private int start = 0; private final int paintWidth = 10; public RadarView(Context context) { super(context); init(); } public RadarView(Context context, AttributeSet attrs) { super(context, attrs); init(); } private void init() { initPaint(); mThread = new ScanThread(); setBackgroundColor(Color.TRANSPARENT); } private void initPaint() { mPaintLine = new Paint(); mPaintLine.setStrokeWidth(paintWidth); mPaintLine.setAntiAlias(true); mPaintLine.setStyle(Style.STROKE); mPaintLine.setColor(0xffff0000); mPaintSector = new Paint(); mPaintSector.setColor(0x9D00ff00); mPaintSector.setAntiAlias(true); } public void setViewSize(int size) { this.viewSize = size; mShader = new SweepGradient(viewSize >> 1, viewSize >> 1, Color.TRANSPARENT, Color.GREEN); setMeasuredDimension(viewSize, viewSize); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { setMeasuredDimension(viewSize, viewSize); } public void start() { mThread.start(); isStart = true; } public void stop() { if (isStart) { Thread.interrupted(); isStart = false; } } private Shader mShader = new SweepGradient(viewSize >> 1, viewSize >> 1, Color.TRANSPARENT, Color.GREEN); private Matrix matrix = new Matrix(); @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); int halfRadaSize = viewSize >> 1; canvas.drawCircle(halfRadaSize, halfRadaSize, halfRadaSize >> 1, mPaintLine); canvas.drawCircle(halfRadaSize, halfRadaSize, halfRadaSize - (paintWidth >> 1), mPaintLine); canvas.drawLine(halfRadaSize, 0, halfRadaSize, viewSize, mPaintLine); canvas.drawLine(0, halfRadaSize, viewSize, halfRadaSize, mPaintLine); mPaintSector.setShader(mShader); canvas.concat(matrix); canvas.drawCircle(halfRadaSize, halfRadaSize, halfRadaSize - paintWidth, mPaintSector); } protected class ScanThread extends Thread { int halfRadaSize = viewSize >> 1; @Override public void run() { while (isStart) { start = start + 2; matrix.reset(); matrix.postRotate(start, halfRadaSize, halfRadaSize); postInvalidate(); try { Thread.sleep(10); } catch (InterruptedException e) { e.printStackTrace(); } } } } }
希望本文所述对大家Android程序设计有所帮助。
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