我正在尝试制作一个简单的动态壁纸,当用户触摸他的屏幕时,会在该位置绘制一个位图。我面临 2 个问题,如果我在 Runnable 中绘制它,那么它会不断创建位图,如果我在外面绘制它,它会不断闪烁。我注意到,如果我改变可运行闪烁的延迟时间也会改变,如果我完全删除可运行,那么它画得很好,但位置变得很奇怪。
这是我的代码。这个连续闪烁。
package com.example.live_wallpaper_p1;
import android.app.WallpaperManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.os.Bundle;
import android.os.Handler;
import android.service.wallpaper.WallpaperService;
import android.view.SurfaceHolder;
public class DemoWallpaperService extends WallpaperService {
@Override
public Engine onCreateEngine() {
return new DemoWallpaperEngine();
}
private class DemoWallpaperEngine extends Engine{
private boolean mVisible = false;
private final Handler mHandler = new Handler();
private Bitmap imm;
private float xcor;
private float ycor;
BitmapFactory.Options option;
DemoWallpaperEngine()
{
imm = Bitmap.createBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.icon, option));
}
private final Runnable mUpdateDisplay = new Runnable() {
@Override
public void run() {
draw();
}};
@Override
public Bundle onCommand(String action, int x, int y, int z, Bundle extras, boolean resultRequested) {
if (action.equals(WallpaperManager.COMMAND_TAP)) {
xcor=x;
ycor=y;
final SurfaceHolder holder = getSurfaceHolder();
Canvas c = null;
try {
c = holder.lockCanvas();
if (c != null) {
c.drawBitmap(imm, xcor-(imm.getWidth()/2), ycor-(imm.getHeight()/2),null);
//drawCube(c);
}
} finally {
if (c != null)
holder.unlockCanvasAndPost(c);
}
}
return null;
}
private void draw() {
SurfaceHolder holder = getSurfaceHolder();
Canvas c = null;
try {
c = holder.lockCanvas();
if (c != null) {
//do something
}
} finally {
if (c != null)
holder.unlockCanvasAndPost(c);
}
mHandler.removeCallbacks(mUpdateDisplay);
if (mVisible) {
mHandler.postDelayed(mUpdateDisplay, 10);
}
}
@Override
public void onVisibilityChanged(boolean visible) {
mVisible = visible;
if (visible) {
draw();
} else {
mHandler.removeCallbacks(mUpdateDisplay);
}
}
@Override
public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
draw();
}
@Override
public void onSurfaceDestroyed(SurfaceHolder holder) {
super.onSurfaceDestroyed(holder);
mVisible = false;
mHandler.removeCallbacks(mUpdateDisplay);
}
@Override
public void onDestroy() {
super.onDestroy();
mVisible = false;
mHandler.removeCallbacks(mUpdateDisplay);
}
}
}