java.lang.OutOfMemoryError：Xamarin Android

问题描述：

正在获取java.lang.OutOfMemoryError虽然尝试GetPixels的mutable副本的位图。java.lang.OutOfMemoryError：Xamarin Android

下面是代码：

public async Task<Bitmap> LoadScaledDownBitmapForDisplayAsync(string path, BitmapFactory.Options options, int reqWidth, int reqHeight) 
{ 
    // Calculate inSampleSize 
    options.InSampleSize = CalculateInSampleSize(options, reqWidth, reqHeight); 
    // Decode bitmap with inSampleSize set  
    options.InJustDecodeBounds = true;   
    Bitmap mutableBitmap = BitmapFactory.DecodeFile(path, options); 
    Bitmap bitmap = mutableBitmap.Copy(Bitmap.Config.Argb8888, true);   
    allpixels = new int[bitmap.Height * bitmap.Width]; 
    bitmap.GetPixels(allpixels, 0, bitmap.Width, 0, 0, bitmap.Width, bitmap.Height); 
    Bitmap bitmapToDisplay = null; 
    for (int i = 0; i < allpixels.Length; i++) 
    { 
    if (allpixels[i] == Color.Black) 
    { 
     allpixels[i] = Color.Gray; 
     int alpha = 0x00; 
     allpixels[i] = Color.Red; 

     bitmap.SetPixels(allpixels, 0, bitmap.Width, 0, 0, bitmap.Width, bitmap.Height); 
      } 
      } 

    return bitmap; 
}

错误：

05-25 17:24:41.945 D/dalvikvm(12002): GC_FOR_ALLOC freed 701K, 2% free 259110K/261936K, paused 53ms, total 54ms 
05-25 17:24:42.850 I/dalvikvm-heap(12002): Clamp target GC heap from 256.376MB to 256.000MB 
05-25 17:24:42.850 D/dalvikvm(12002): GC_FOR_ALLOC freed 276K, 1% free 259383K/261936K, paused 59ms, total 59ms 
05-25 17:24:42.890 I/dalvikvm-heap(12002): Clamp target GC heap from 256.643MB to 256.000MB 
05-25 17:24:42.890 D/dalvikvm(12002): GC_FOR_ALLOC freed <1K, 1% free 259655K/261936K, paused 37ms, total 37ms 
05-25 17:24:42.890 I/dalvikvm-heap(12002): Forcing collection of SoftReferences for 281824-byte allocation 
05-25 17:24:42.930 I/dalvikvm-heap(12002): Clamp target GC heap from 258.635MB to 256.000MB 
05-25 17:24:42.930 D/dalvikvm(12002): GC_BEFORE_OOM freed 10K, 1% free 259645K/261936K, paused 42ms, total 42ms 
05-25 17:24:42.930 E/dalvikvm-heap(12002): Out of memory on a 281824-byte allocation. 
05-25 17:24:42.930 I/dalvikvm(12002): "main" prio=5 tid=1 RUNNABLE 
05-25 17:24:42.930 I/dalvikvm(12002): | group="main" sCount=0 dsCount=0 obj=0x41caa578 self=0x41c88a60 
05-25 17:24:42.930 I/dalvikvm(12002): | sysTid=12002 nice=-16 sched=0/0 cgrp=apps handle=1074249724 
05-25 17:24:42.930 I/dalvikvm(12002): | state=R schedstat=(763705373545 16690026208 56421) utm=75810 stm=560 core=3 
05-25 17:24:42.930 I/dalvikvm(12002): at mono.android.view.View_OnClickListenerImplementor.n_onClick(Native Method) 
05-25 17:24:42.930 I/dalvikvm(12002): at mono.android.view.View_OnClickListenerImplementor.onClick(View_OnClickListenerImplementor.java:29) 
05-25 17:24:42.930 I/dalvikvm(12002): at android.view.View.performClick(View.java:4475) 
05-25 17:24:42.930 I/dalvikvm(12002): at android.view.View$PerformClick.run(View.java:18786) 
05-25 17:24:42.930 I/dalvikvm(12002): at android.os.Handler.handleCallback(Handler.java:730) 
05-25 17:24:42.930 I/dalvikvm(12002): at android.os.Handler.dispatchMessage(Handler.java:92) 
05-25 17:24:42.930 I/dalvikvm(12002): at android.os.Looper.loop(Looper.java:176) 
05-25 17:24:42.930 I/dalvikvm(12002): at android.app.ActivityThread.main(ActivityThread.java:5419) 
05-25 17:24:42.930 I/dalvikvm(12002): at java.lang.reflect.Method.invokeNative(Native Method) 
05-25 17:24:42.930 I/dalvikvm(12002): at java.lang.reflect.Method.invoke(Method.java:525) 
05-25 17:24:42.930 I/dalvikvm(12002): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046) 
05-25 17:24:42.930 I/dalvikvm(12002): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862) 
05-25 17:24:42.935 I/dalvikvm(12002): at dalvik.system.NativeStart.main(Native Method) 
05-25 17:24:42.935 I/dalvikvm(12002): 
05-25 17:24:42.935 W/dalvikvm(12002): JNI WARNING: JNI method called with exception pending 
05-25 17:24:42.935 W/dalvikvm(12002):    in Lmono/android/view/View_OnClickListenerImplementor;.n_onClick:(Landroid/view/View;)V (SetIntArrayRegion) 
05-25 17:24:42.935 W/dalvikvm(12002): Pending exception is: 
05-25 17:24:42.935 I/dalvikvm(12002): java.lang.OutOfMemoryError: 
05-25 17:24:42.935 I/dalvikvm(12002): at mono.android.view.View_OnClickListenerImplementor.n_onClick(Native Method) 
05-25 17:24:42.935 I/dalvikvm(12002): at mono.android.view.View_OnClickListenerImplementor.onClick(View_OnClickListenerImplementor.java:29) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.view.View.performClick(View.java:4475) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.view.View$PerformClick.run(View.java:18786) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.os.Handler.handleCallback(Handler.java:730) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.os.Handler.dispatchMessage(Handler.java:92) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.os.Looper.loop(Looper.java:176) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.app.ActivityThread.main(ActivityThread.java:5419) 
05-25 17:24:42.935 I/dalvikvm(12002): at java.lang.reflect.Method.invokeNative(Native Method) 
05-25 17:24:42.935 I/dalvikvm(12002): at java.lang.reflect.Method.invoke(Method.java:525) 
05-25 17:24:42.935 I/dalvikvm(12002): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046) 
05-25 17:24:42.935 I/dalvikvm(12002): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862) 
05-25 17:24:42.935 I/dalvikvm(12002): at dalvik.system.NativeStart.main(Native Method) 
05-25 17:24:42.935 I/dalvikvm(12002): "main" prio=5 tid=1 NATIVE 
05-25 17:24:42.935 I/dalvikvm(12002): | group="main" sCount=0 dsCount=0 obj=0x41caa578 self=0x41c88a60 
05-25 17:24:42.935 I/dalvikvm(12002): | sysTid=12002 nice=-16 sched=0/0 cgrp=apps handle=1074249724 
05-25 17:24:42.935 I/dalvikvm(12002): | state=R schedstat=(763706606629 16692302499 56458) utm=75810 stm=560 core=3 
05-25 17:24:42.935 I/dalvikvm(12002): #00 pc 000012fe /system/lib/libcorkscrew.so (unwind_backtrace_thread+29) 
05-25 17:24:42.935 I/dalvikvm(12002): #01 pc 00060b82 /system/lib/libdvm.so (dvmDumpNativeStack(DebugOutputTarget const*, int)+33) 
05-25 17:24:42.935 I/dalvikvm(12002): #02 pc 00054c20 /system/lib/libdvm.so (dvmDumpThreadEx(DebugOutputTarget const*, Thread*, bool)+395) 
05-25 17:24:42.935 I/dalvikvm(12002): #03 pc 00054c8e /system/lib/libdvm.so (dvmDumpThread(Thread*, bool)+25) 
05-25 17:24:42.935 I/dalvikvm(12002): #04 pc 00038f00 /system/lib/libdvm.so 
05-25 17:24:42.935 I/dalvikvm(12002): #05 pc 0003af50 /system/lib/libdvm.so 
05-25 17:24:42.935 I/dalvikvm(12002): at mono.android.view.View_OnClickListenerImplementor.n_onClick(Native Method) 
05-25 17:24:42.935 I/dalvikvm(12002): at mono.android.view.View_OnClickListenerImplementor.onClick(View_OnClickListenerImplementor.java:29) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.view.View.performClick(View.java:4475) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.view.View$PerformClick.run(View.java:18786) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.os.Handler.handleCallback(Handler.java:730) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.os.Handler.dispatchMessage(Handler.java:92) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.os.Looper.loop(Looper.java:176) 
05-25 17:24:42.935 I/dalvikvm(12002): at android.app.ActivityThread.main(ActivityThread.java:5419) 
05-25 17:24:42.935 I/dalvikvm(12002): at java.lang.reflect.Method.invokeNative(Native Method) 
05-25 17:24:42.935 I/dalvikvm(12002): at java.lang.reflect.Method.invoke(Method.java:525) 
05-25 17:24:42.935 I/dalvikvm(12002): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046) 
05-25 17:24:42.935 I/dalvikvm(12002): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862) 
In mgmain JNI_OnLoad 
05-25 17:24:42.940 I/dalvikvm(12002): at dalvik.system.NativeStart.main(Native Method) 
05-25 17:24:42.940 I/dalvikvm(12002): 
05-25 17:24:42.940 E/dalvikvm(12002): VM aborting 
05-25 17:24:42.945 E/mono-rt (12002): Stacktrace: 
05-25 17:24:42.945 E/mono-rt (12002):

终于得到这个消息：

Got a SIGSEGV while executing native code. This usually indicates 
05-25 17:24:42.985 E/mono-rt (12002): a fatal error in the mono runtime or one of the native libraries 
05-25 17:24:42.985 E/mono-rt (12002): used by your application.

任何想法或帮助将是非常有帮助。

你的形象有多大？如果没有发生OutOfMemoryException，您无法解码巨大的图像。或者你的记忆已经满了。 –

@ Sven-MichaelStübe我能够在ImageView中显示图像而没有错误，但是当试图获取位图的可变副本时，我面临着这个错误。 – Janmejoy

CalculateInSampleSize是否膨胀完整的位图以获取测量结果？也许在那里你需要设置injustdecodebounds = true。我不能看到代码，但会冒险猜测你可能会膨胀位图，以获得大小，然后膨胀一个新的可变吗？ –

答

我强烈建议在你的位图代码中使用using声明。这应该有助于处理适当的同行包装。如果您不使用using语句，则确保您正在调用.Dipose()或将对等包装设置为null以断开连接。其次，我还建议通过GC.Collect()或JavaSystem.GC()调用一个手册GC，以帮助减少操作结束时的工作集。

即：

using (var bitmap = HowIGetThisBitMap()) 
{ 
    //How I use this bitmap while in scope 
} 

GC.Collect(); //I then ensure I manually invoke the GC

是的，这是有点对传统的.NET项目，但我们已经在有记忆的敏感操作的移动设备上。对于没有大容量RAM缓存的低端设备尤其如此。这是我们想要拨打GC.Collect()的一个代码点。

java.lang.OutOfMemoryError：Xamarin Android

相关推荐