这几天在搞基于位置的AR应用，採用了github上两款开源项目：

这两个项目实现机制大致同样。我选取的是android-argument-reality-framework。原因是我觉得他的代码结构要清晰非常多（纯属个人意见）。

这两个项目的demo在执行时都会crash，通过查看控制台，能够看到例如以下信息：

07-31 14:35:38.685: W/dalvikvm(13686): ReferenceTable overflow (max=1024)07-31 14:35:38.685: W/dalvikvm(13686): JNI pinned array reference table (0x5fc810) dump:07-31 14:35:38.685: W/dalvikvm(13686):   Last 10 entries (of 1024):07-31 14:35:38.685: W/dalvikvm(13686):      1023: 0x4130ada8 char[] (29 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1022: 0x4130a768 char[] (29 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1021: 0x413ad8d0 char[] (29 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1020: 0x413aa990 char[] (36 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1019: 0x40ea2eb0 char[] (5 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1018: 0x40e262d8 char[] (5 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1017: 0x40ee8000 char[] (4 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1016: 0x40e97418 char[] (4 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1015: 0x413a9e38 char[] (22 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1014: 0x413a9858 char[] (33 elements)07-31 14:35:38.685: W/dalvikvm(13686):   Summary:07-31 14:35:38.685: W/dalvikvm(13686):         1 of byte[] (128 elements)07-31 14:35:38.685: W/dalvikvm(13686):        50 of char[] (4 elements) (2 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        50 of char[] (5 elements) (2 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        25 of char[] (22 elements) (25 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (23 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (24 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (25 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (27 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (28 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):       508 of char[] (29 elements) (508 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (31 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        49 of char[] (33 elements) (49 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        25 of char[] (34 elements) (25 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        50 of char[] (36 elements) (50 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        25 of char[] (37 elements) (25 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        49 of char[] (39 elements) (49 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (44 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (63 elements) (24 unique instances)07-31 14:35:38.685: E/dalvikvm(13686): Failed adding to JNI pinned array ref table (1024 entries)07-31 14:35:38.685: I/dalvikvm(13686): "main" prio=5 tid=1 RUNNABLE07-31 14:35:38.685: I/dalvikvm(13686):   | group="main" sCount=0 dsCount=0 obj=0x40a59460 self=0x34383007-31 14:35:38.685: I/dalvikvm(13686):   | sysTid=13686 nice=0 sched=0/0 cgrp=default handle=107451738407-31 14:35:38.685: I/dalvikvm(13686):   | schedstat=( 23316582697 3886607959 27513 ) utm=2194 stm=137 core=007-31 14:35:38.685: I/dalvikvm(13686):   at android.graphics.Paint.native_measureText(Native Method)07-31 14:35:38.685: I/dalvikvm(13686):   at android.graphics.Paint.measureText(Paint.java:1288)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.lib.gui.PaintScreen.getTextWidth(PaintScreen.java:153)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.lib.gui.TextObj.prepTxt(TextObj.java:107)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.lib.gui.TextObj.
     
      (TextObj.java:65)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.lib.gui.TextObj.
      
       (TextObj.java:50)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.marker.ImageMarker.drawTitle(ImageMarker.java:135)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.marker.ImageMarker.draw(ImageMarker.java:120)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.DataView.draw(DataView.java:252)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.AugmentedView.onDraw(MixView.java:1411)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.View.draw(View.java:10978)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.drawChild(ViewGroup.java:2887)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.drawChild(ViewGroup.java:2885)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.drawChild(ViewGroup.java:2885)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.View.draw(View.java:10981)07-31 14:35:38.685: I/dalvikvm(13686):   at android.widget.FrameLayout.draw(FrameLayout.java:450)07-31 14:35:38.685: I/dalvikvm(13686):   at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:2126)07-31 14:35:38.690: I/dalvikvm(13686):   at android.view.ViewRootImpl.draw(ViewRootImpl.java:2026)07-31 14:35:38.690: I/dalvikvm(13686):   at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1634)07-31 14:35:38.690: I/dalvikvm(13686):   at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2442)07-31 14:35:38.690: I/dalvikvm(13686):   at android.os.Handler.dispatchMessage(Handler.java:99)07-31 14:35:38.690: I/dalvikvm(13686):   at android.os.Looper.loop(Looper.java:137)07-31 14:35:38.690: I/dalvikvm(13686):   at android.app.ActivityThread.main(ActivityThread.java:4575)07-31 14:35:38.690: I/dalvikvm(13686):   at java.lang.reflect.Method.invokeNative(Native Method)07-31 14:35:38.690: I/dalvikvm(13686):   at java.lang.reflect.Method.invoke(Method.java:511)07-31 14:35:38.690: I/dalvikvm(13686):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)07-31 14:35:38.690: I/dalvikvm(13686):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)07-31 14:35:38.690: I/dalvikvm(13686):   at dalvik.system.NativeStart.main(Native Method)07-31 14:35:38.690: E/dalvikvm(13686): VM aborting
      
     

通过 和 大致了解到了原因就是在频繁调用native_measureText可能出现了内存泄露，可是始终没有好的解决方式。

最后经过一番折腾，最终在

id=22里找到的解决的，给出的解决方式例如以下：

。

改动android-augment-reality-framework项目的src/com/jwetherell/augmented_reality/ui/objects/PaintableObject.java中的getTextWidth方法为例如以下代码就可以：

/**	 * Get the width of the text String.	 * 	 * @param txt	 *            CharSequence to get the width of.	 * @param start	 *            Start of the text.	 * @param end	 *            End of the text.	 * @return float width of the text String.	 * @throws NullPointerException	 *             if the String param is NULL.	 */	public float getTextWidth(CharSequence text) {		if (text == null)			throw new NullPointerException();		TextPaint textPaint = new TextPaint(paint);		int widthWrap = 1000; // you may have to change this		StaticLayout layout = measure(textPaint, text, widthWrap);		return getMaxLineWidth(layout);	}	private float getMaxLineWidth(StaticLayout layout) {		float maxLine = 0.0f;		int lineCount = layout.getLineCount();		for (int i = 0; i < lineCount; i++) {			if (layout.getLineWidth(0) > maxLine) {				maxLine = layout.getLineWidth(0);			}		}		return maxLine;	}	private StaticLayout measure(TextPaint textPaint, CharSequence text,			Integer wrapWidth) {		int boundedWidth = Integer.MAX_VALUE;		if (wrapWidth != null && wrapWidth > 0) {			boundedWidth = wrapWidth;		}		StaticLayout layout = new StaticLayout(text, textPaint, boundedWidth,				Alignment.ALIGN_NORMAL, 1.0f, 0.0f, false);		return layout;	}