动态壁纸+ +位帆布

本文介绍了动态壁纸+ +位帆布的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

直升机大家！我有这个活的壁纸在女巫我试图表明一个位图低谷的画布（可绘制资源是400K 1900x1200的JPG格式）。它强制关闭，我不知道为什么（这是我的第一个Android项目）。这些都是重要位：

Helo everyone! I have this live wallpaper in witch I try to show a bitmap trough a canvas (the drawable resource is a 400k 1900x1200 jpg). It force-closes and I don't get why (it's my first Android project). These are the "important" bits:

    wallEngine() { // CONSTRUCTOR   <<<<<<<<<<<<<<<<<<<
                            mStartTime = SystemClock.elapsedRealtime();


                            Log.v(Logcat, "Contructor ok");

                        }
                //====================================== INIT
                        private final Runnable mDrawWall = new Runnable() { //=========== RUN
                            public void run() {
                                drawFrame();
                            }
                        };

   void drawFrame() {

                           final SurfaceHolder holder = getSurfaceHolder();
                           Canvas c = null;
                           try {
                                c = holder.lockCanvas();
                                if (c != null) {
                                    // draw something
                                    updatePhysics();
                                    doDraw(c);
                                }
                            } finally {
                                if (c != null) holder.unlockCanvasAndPost(c);
                            }

                            // Reschedule the next redraw
                            mHandler.removeCallbacks(mDrawWall);
                            if (mVisible) {
                                mHandler.postDelayed(mDrawWall, 5000);
                            }
                        }


    private void doDraw(Canvas canvas) {
                      //backgroundImage.prepareToDraw();
                    canvas.drawBitmap(this.backgroundImage, 0, 0, null);
                        }


public void onCreate(SurfaceHolder surfaceHolder) {

                            super.onCreate(surfaceHolder);                      surfaceHolder.setFormat(android.graphics.PixelFormat.RGBA_8888);

                            BitmapFactory.Options options = new BitmapFactory.Options();
                            options.inPurgeable = true;

                            this.backgroundImage = BitmapFactory.decodeResource(getResources(),
                                com.misca.livewallpapers.parang.R.drawable.a, options);

                            //backgroundImage.prepareToDraw();
                            //setTouchEventsEnabled(true);
                            Log.v(Logcat, "onCreate ok");
                        }

而logcat的错误，当我尝试我的手机上运行它是：

And the logcat errors when i try to run it on my phone are :

ERROR/AndroidRuntime(7722): FATAL EXCEPTION: main
ERROR/AndroidRuntime(7722): java.lang.NullPointerException
ERROR/AndroidRuntime(7722):     at android.graphics.Canvas.throwIfRecycled(Canvas.java:957)
ERROR/AndroidRuntime(7722):     at android.graphics.Canvas.drawBitmap(Canvas.java:983)
ERROR/AndroidRuntime(7722):     at com.misca.livewallpapers.parang.liveWallpaper$wallEngine.doDraw(liveWallpaper.java:115)
ERROR/AndroidRuntime(7722):     at com.misca.livewallpapers.parang.liveWallpaper$wallEngine.drawFrame(liveWallpaper.java:75)
ERROR/AndroidRuntime(7722):     at com.misca.livewallpapers.parang.liveWallpaper$wallEngine.onSurfaceChanged(liveWallpaper.java:157)
ERROR/AndroidRuntime(7722):     at android.service.wallpaper.WallpaperService$Engine.updateSurface(WallpaperService.java:590)
ERROR/AndroidRuntime(7722):     at android.service.wallpaper.WallpaperService$Engine.attach(WallpaperService.java:654)
ERROR/AndroidRuntime(7722):     at android.service.wallpaper.WallpaperService$IWallpaperEngineWrapper.executeMessage(WallpaperService.java:878)
ERROR/AndroidRuntime(7722):     at com.android.internal.os.HandlerCaller$MyHandler.handleMessage(HandlerCaller.java:61)
ERROR/AndroidRuntime(7722):     at android.os.Handler.dispatchMessage(Handler.java:99)
ERROR/AndroidRuntime(7722):     at android.os.Looper.loop(Looper.java:123)
ERROR/AndroidRuntime(7722):     at android.app.ActivityThread.main(ActivityThread.java:3848)
ERROR/AndroidRuntime(7722):     at java.lang.reflect.Method.invokeNative(Native Method)
ERROR/AndroidRuntime(7722):     at java.lang.reflect.Method.invoke(Method.java:507)
ERROR/AndroidRuntime(7722):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
ERROR/AndroidRuntime(7722):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
03-23 00:26:42.309: ERROR/AndroidRuntime(7722):     at dalvik.system.NativeStart.main(Native Method)

感谢您！：）

=======================
新闻：

=======================News:

                        private void doDraw(Canvas canvas) {
                        //backgroundImage.prepareToDraw();
                        if(this.backgroundImage!=null)
                        canvas.drawBitmap(this.backgroundImage, 0, 0, null);
                        else
                        Log.v(Logcat, "null");

                    }

和似乎位为空。现在我用480x800的合作，以确保没有内存问题。该应用程序不与if语句了崩溃（空黑屏）

And seems the bitmap is null. Now i'm working with a 480x800 to ensure there are no memory problems. The app doesn't crash anymore with the if statement (empty black screen)

1900x1200

动态壁纸+ +位帆布

问题描述

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