我有一个对话框,用户可以在对话框中自由绘制.
对话框正在扩展视图,并且创建绘图区域
bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
但是,不需要保留绘图,并且当用户关闭对话框并再次重新打开时,不需要保留他之前的绘图并从null重绘.
详细代码:// DoodleView constructor initializes the DoodleView public DoodleView(Context context, AttributeSet attrs) { super(context, attrs); // pass context to View's constructor paintScreen = new Paint(); // used to display bitmap onto screen // set the initial display settings for the painted line paintLine = new Paint(); paintLine.setAntiAlias(true); // smooth edges of drawn line paintLine.setColor(Color.BLACK); // default color is black paintLine.setStyle(Paint.Style.STROKE); // solid line paintLine.setStrokeWidth(25); // set the default line width paintLine.setStrokeCap(Paint.Cap.ROUND); // rounded line ends pathMap = new HashMap(); previousPointMap = new HashMap (); } // end DoodleView constructor // Method onSizeChanged creates BitMap and Canvas after app displays @Override public void onSizeChanged(int w, int h, int oldW, int oldH) { bitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888); bitmapCanvas = new Canvas(bitmap); bitmap.eraseColor(Color.parseColor("#80FFFFFF")); // erase the BitMap with white } // end method onSizeChanged // clear the painting public void recycling() { bitmap.recycle(); }
public void write_board () { writing_dialog = new Dialog(Apple.this, android.R.style.Theme_Translucent_NoTitleBar); WindowManager.LayoutParams lp = writing_dialog.getWindow().getAttributes(); lp.dimAmount = 0.5f; writing_dialog.getWindow().addFlags(WindowManager.LayoutParams.FLAG_DIM_BEHIND); Window window = writing_dialog.getWindow(); window.setGravity(Gravity.CENTER); writing_dialog.setContentView(R.layout.alert_drawing_pad); writing_dialog.setCancelable(true); writing_dialog.show(); writing_dialog.setVolumeControlStream(AudioManager.STREAM_MUSIC); doodleView = (DoodleView) writing_dialog.findViewById(R.id.doodleView); alert_close.setOnClickListener(new OnClickListener() { public void onClick(View v) { writing_dialog.dismiss(); doodleView.recycling(); return; } });
我发现在打开对话框几次(使用三星Note2后7到8次)后,对话框会滞后几秒钟而手机没有响应,再稍后再按一下,对话框会再次出现,一切都是好.
此时的logcat报告 E/OpenGLRenderer(25296): Out of memory!
并且它持续了一段时间没有挂起.
然而,如果进一步按下绘图板,则会出现严重的内存错误,这次系统会挂起.
FATAL EXCEPTION: main java.lang.OutOfMemoryError at android.graphics.Bitmap.nativeCreate(Native Method) at android.graphics.Bitmap.createBitmap(Bitmap.java:726) at android.graphics.Bitmap.createBitmap(Bitmap.java:703) at android.graphics.Bitmap.createBitmap(Bitmap.java:670) at com.abc.abc.DoodleView.onSizeChanged(DoodleView.java:60) at android.view.View.sizeChange(View.java:15326) at android.view.View.setFrame(View.java:15290) at android.view.View.layout(View.java:15201) at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1076) at android.view.View.layout(View.java:15204) at android.view.ViewGroup.layout(ViewGroup.java:4793) at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1076) at android.view.View.layout(View.java:15204) at android.view.ViewGroup.layout(ViewGroup.java:4793) at android.widget.FrameLayout.onLayout(FrameLayout.java:448) at android.view.View.layout(View.java:15204) at android.view.ViewGroup.layout(ViewGroup.java:4793) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1677) at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1531) at android.widget.LinearLayout.onLayout(LinearLayout.java:1440) at android.view.View.layout(View.java:15204) at android.view.ViewGroup.layout(ViewGroup.java:4793) at android.widget.FrameLayout.onLayout(FrameLayout.java:448) at android.view.View.layout(View.java:15204) at android.view.ViewGroup.layout(ViewGroup.java:4793) at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2263) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2009) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1251) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6379) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:791) at android.view.Choreographer.doCallbacks(Choreographer.java:591) at android.view.Choreographer.doFrame(Choreographer.java:561) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:777) at android.os.Handler.handleCallback(Handler.java:730) at android.os.Handler.dispatchMessage(Handler.java:92) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:5493) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:525) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1209) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1025) at dalvik.system.NativeStart.main(Native Method)
bitmap.recycle();
每当用户关闭对话框时,我都会进行研究和添加.但它仍然报告同样的错误.
每当用户关闭对话框时,有没有办法处理位图?
谢谢!
首先使画布或任何其他对象必须位图的引用无效
if (bitmapCanvas != null) { bitmapCanvas.setBitmap(null); bitmapCanvas = null; }
第二个发布位图资源
if (bitmap != null) { bitmap.recycle(); bitmap = null; }
如果需要,请将位图保持为WeakReference
WeakReference<Bitmap> bitmap; if (bitmap != null) { bitmap.get().recycle(); bitmap.clear(); bitmap= null; }
您应该在关闭对话框时调用此方法
bitmap.recycle(); bitmap = null;
bitmap.recycle();
释放位图中使用的本机堆.将其设置为null是为了帮助GC快速收集您的参考.