我想问一下这里已经解决过一两次的问题,但我发现的任何信息都无法帮助我克服几天前遇到的问题.
我想使用画布为Android制作一个动态壁纸 – 它的图形复杂程度不足以要求OpenGL.为简单起见,假设它由实心背景和两个较小的矩形组成.
绘图由三个独立的阶段组成(单线程)：
> backgroundDraw()请求整个画布锁并在其上绘制纯色
> draw1()请求部分(Rect r1)锁定并仅在锁定的矩形上绘制
> draw2()请求部分(Rect r2)锁定并仅在锁定的矩形上绘制
我在多个Android版本(模拟器和设备)上测试了它：2.1,2.2,2.3.3.它似乎只适用于后者(这里：http://home.elka.pw.edu.pl/~pgawron/include/Android/android_233.jpg).在以前的Android版本中,SurfaceHolder.lockCanvas(Rect dirty)调整大小(！)脏参数作为参数传递给全屏的大小,并使用它进一步绘制结果在整个屏幕上绘制(此处：http://home.elka.pw.edu.pl/~pgawron/include/Android/android_22.jpg).事实上,我可以看到每个矩形是如何被绘制的(全屏)：整个屏幕很快就会改变它的颜色.
不幸的是谷歌找不到任何关于lockCanvas(Rect脏)用法的正确例子.下面我附上我用于测试目的的完整且唯一的类.可以在提供屏幕截图的位置访问完整的eclipse项目.
如果有人能够最终帮助我并更正我的代码(如果我的代码中只有问题),我将非常感激.我真的浪费了太多时间.
BR,
彼得雷利
package sec.polishcode.test;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.os.SystemClock;
import android.service.wallpaper.WallpaperService;
import android.util.Log;
import android.view.SurfaceHolder;
public class TestLiveWallpaper extends WallpaperService{
@Override
public Engine onCreateEngine() {
return new MyEngine();
}
class MyEngine extends Engine implements SurfaceHolder.Callback {
private final String LOGTAG = MyEngine.class.getSimpleName();
private Paint backgroundPaint = new Paint();
private Paint mPaint1 = new Paint();
private Paint mPaint2 = new Paint();
private long lastVisibilityOnChange;
private final Rect r1 = new Rect(20,20,60,280);
private final Rect r2 = new Rect(70,110,280);
public MyEngine() {
getSurfaceHolder().addCallback(this);
backgroundPaint.setColor(Color.YELLOW);
mPaint1.setColor(Color.LTGRAY);
mPaint2.setColor(Color.magenta);
}
@Override
public void surfaceChanged(SurfaceHolder arg0,int arg1,int arg2,int arg3) {
drawSurface();
}
@Override
public void surfaceCreated(SurfaceHolder arg0) {
Log.i(LOGTAG,"surfaceCreated");
}
@Override
public void surfaceDestroyed(SurfaceHolder arg0) {
Log.i(LOGTAG,"surfaceDestroyed");
}
@Override
public void onCreate(SurfaceHolder surfaceHolder) {
super.onCreate(surfaceHolder);
setTouchEventsEnabled(true);
}
@Override
public void onVisibilityChanged(boolean visible) {
if (!visible)
return;
lastVisibilityOnChange = SystemClock.elapsedRealtime();
drawSurface();
}
@Override
public void onOffsetsChanged(float xOffset,float yOffset,float xStep,float yStep,int xPixels,int yPixels) {
if (SystemClock.elapsedRealtime() - lastVisibilityOnChange > 30)
return;
Log.i(LOGTAG,"onOffsetsChanged filtered");
drawSurface();
}
private void drawSurface() {
backgroundDraw();
draw1();
draw2();
}
private void backgroundDraw() {
final SurfaceHolder holder = getSurfaceHolder();
Canvas c = null;
try {
c = holder.lockCanvas();
if (c != null) {
c.drawRect(holder.getSurfaceFrame(),backgroundPaint);
}
} finally {
if (c != null)
holder.unlockCanvasAndPost(c);
}
}
private void draw1() {
final SurfaceHolder holder = getSurfaceHolder();
Canvas c = null;
try {
c = holder.lockCanvas(r1);
if (c != null) {
c.drawRect(r1,mPaint1);
}
} finally {
if (c != null)
holder.unlockCanvasAndPost(c);
}
}
private void draw2() {
final SurfaceHolder holder = getSurfaceHolder();
Canvas c = null;
try {
c = holder.lockCanvas(r2);
if (c != null) {
c.drawRect(r2,mPaint2);
}
} finally {
if (c != null)
holder.unlockCanvasAndPost(c);
}
}
}
}
原文地址：https://www.jb51.cc/android/430380.html
版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 dio@foxmail.com 举报，一经查实，本站将立刻删除。
