1.View适用于主动更新,SurfaceView 适用于被动更新,如频繁的刷新
2.View在UI线程更新,在非UI线程更新会报错,当在主线程更新view时如果耗时过长也会出错, SurfaceView在子线程刷新不会阻塞主线程,适用于界面频繁更新、对帧率要求较高的情况
3.SurfaceView底层利用双缓冲机制,绘图时不会出现闪烁问题(双缓冲技术会把要处理的图片在内存中处理好之后,把要画的东西先画到一个内存区域里,然后整体的一次性画出来,将其显示在屏幕上)
SurfaceView的使用
public class SurfaceViewL extends SurfaceView implements SurfaceHolder.Callback, Runnable {
// SurfaceHolder
private SurfaceHolder mSurfaceHolder;
// 画布
private Canvas mCanvas;
// 子线程标志位
private boolean isDrawing;
public SurfaceViewL(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
mSurfaceHolder = getHolder();
mSurfaceHolder.addCallback(this);
setFocusable(true);
setFocusableInTouchMode(true);
this.setKeepScreenOn(true);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {//创建
isDrawing = true;
new Thread(this).start();
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {//改变
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {//销毁
isDrawing = false;
}
@Override
public void run() {
while (isDrawing){
drawing();
}
}
private void drawing() {
try {
mCanvas = mSurfaceHolder.lockCanvas();
//这里进行内容的绘制
...
}finally {
if (mCanvas != null){
mSurfaceHolder.unlockCanvasAndPost(mCanvas);
}
}
}
}