blocks|key|3058387|text|该接口提供了JUnit+Assert。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3058388|你可以做到|3058389|import+static+junit.framework.Assert.*;|code-block|syntax|javascript|3058390|现在您可以使用junit框架中提供的所有函数，如assertTrue、assertEquals和assertNull。|3058391|注意不要通过eclipse导入Junit4框架，这将是org.junit包。您必须使用junit.framework包才能使其在安卓设备或模拟器上工作。|3058392|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/junit/framework/Assert.html^0|6|C|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|6|7|10|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|11|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|12|8|@]|9|@]|C|$]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|C|$]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|C|$]]]|P|$Q|$5|R|S|T|C|$U|V]]]]

The API provides the <a href="http://developer.android.com/reference/junit/framework/Assert.html" rel="nofollow noreferrer">JUnit Assert</a>.

You can do 

<pre><code>import static junit.framework.Assert.*;
</code></pre>

now you can use all the functions like assertTrue, assertEquals, assertNull that are provided in the junit framework. 

Be careful not to import the Junit4 framework through eclipse, that would be the org.junit package. You have to use the junit.framework package to get it working on an android device or the emulator.

blocks|key|317663|text|请参阅嵌入式虚拟机控制文档(来自source+tree的原始超文本标记语言或nicely+formatted副本)。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|317664|基本上，Dalvik+VM默认设置为忽略断言检查，即使.dex字节码包含执行检查的代码也是如此。检查断言可以通过以下两种方式之一打开：|317665|(1)通过以下方式设置系统属性"debug.assert“：|317666|adb+shell+setprop+debug.assert+1|code-block|syntax|javascript|317667|我验证过，只要你在这样做后重新安装你的应用程序，它就能正常工作，或者|317668|(2)向dalvik+VM发送命令行参数"--enable-assert“，这可能不是应用程序开发人员能够做的事情(如果我错了，有人纠正我)。|317669|基本上，有一个可以全局设置的标志，可以在包级别设置，也可以在类级别设置，从而在相应级别启用断言。默认情况下，该标志为off，因此将跳过断言检查。|317670|我在我的示例活动中编写了以下代码：|317671|​|317672|public+class+AssertActivity+extends+Activity+{
++@Override
++protected+void+onCreate(Bundle+savedInstanceState)+{
++++super.onCreate(savedInstanceState);
++++setContentView(R.layout.main);
++++int+x+=+2+%2B+3;
++++assert+x+==+4;
++}
}|317673|317674|对于这段代码，生成的dalvik字节码是(对于Android+2.3.3)：|317675|317676|//+Static+constructor+for+the+class
000318:++++++++++++++++++++++++++++++++++++++++%7C[000318]+com.example.asserttest.AssertActivity.:()V
000328:+1c00+0300++++++++++++++++++++++++++++++%7C0000:+const-class+v0,+Lcom/example/asserttest/AssertActivity;+//+class@0003
00032c:+6e10+0c00+0000+++++++++++++++++++++++++%7C0002:+invoke-virtual+{v0},+Ljava/lang/Class;.desiredAssertionStatus:()Z+//+method@000c
000332:+0a00+++++++++++++++++++++++++++++++++++%7C0005:+move-result+v0
000334:+3900+0600++++++++++++++++++++++++++++++%7C0006:+if-nez+v0,+000c+//+%2B0006
000338:+1210+++++++++++++++++++++++++++++++++++%7C0008:+const/4+v0,+#int+1+//+#1
00033a:+6a00+0000++++++++++++++++++++++++++++++%7C0009:+sput-boolean+v0,+Lcom/example/asserttest/AssertActivity;.$assertionsDisabled:Z+//+field@0000
00033e:+0e00+++++++++++++++++++++++++++++++++++%7C000b:+return-void
000340:+1200+++++++++++++++++++++++++++++++++++%7C000c:+const/4+v0,+#int+0+//+#0
000342:+28fc+++++++++++++++++++++++++++++++++++%7C000d:+goto+0009+//+-0004

:
:

//+onCreate()
00035c:++++++++++++++++++++++++++++++++++++++++%7C[00035c]+com.example.asserttest.AssertActivity.onCreate:(Landroid/os/Bundle;)V
00036c:+6f20+0100+3200+++++++++++++++++++++++++%7C0000:+invoke-super+{v2,+v3},+Landroid/app/Activity;.onCreate:(Landroid/os/Bundle;)V+//+method@0001
000372:+1501+037f++++++++++++++++++++++++++++++%7C0003:+const/high16+v1,+#int+2130903040+//+#7f03
000376:+6e20+0500+1200+++++++++++++++++++++++++%7C0005:+invoke-virtual+{v2,+v1},+Lcom/example/asserttest/AssertActivity;.setContentView:(I)V+//+method@0005
00037c:+1250+++++++++++++++++++++++++++++++++++%7C0008:+const/4+v0,+#int+5+//+#5
00037e:+6301+0000++++++++++++++++++++++++++++++%7C0009:+sget-boolean+v1,+Lcom/example/asserttest/AssertActivity;.$assertionsDisabled:Z+//+field@0000
000382:+3901+0b00++++++++++++++++++++++++++++++%7C000b:+if-nez+v1,+0016+//+%2B000b
000386:+1251+++++++++++++++++++++++++++++++++++%7C000d:+const/4+v1,+#int+5+//+#5
000388:+3210+0800++++++++++++++++++++++++++++++%7C000e:+if-eq+v0,+v1,+0016+//+%2B0008
00038c:+2201+0c00++++++++++++++++++++++++++++++%7C0010:+new-instance+v1,+Ljava/lang/AssertionError;+//+class@000c
000390:+7010+0b00+0100+++++++++++++++++++++++++%7C0012:+invoke-direct+{v1},+Ljava/lang/AssertionError;.:()V+//+method@000b
000396:+2701+++++++++++++++++++++++++++++++++++%7C0015:+throw+v1
000398:+0e00+++++++++++++++++++++++++++++++++++%7C0016:+return-void



Notice+how+the+static+constructor+invokes+the+method+desiredAssertionStatus+on+the+Class+object+and+sets+the+class-wide+variable+$assertionsDisabled;+also+notice+that+in+onCreate(),+all+of+the+code+to+throw+java.lang.AssertionError+is+compiled+in,+but+its+execution+is+contingent+upon+the+value+of+$assertionsDisabled+which+is+set+for+the+Class+object+in+the+static+constructor.

It+appears+that+JUnit's+Assert+class+is+what+is+used+predominantly,+so+it+is+likely+a+safe+bet+to+use+that.+The+flexibility+of+the+assert+keyword+is+the+ability+to+turn+on+assertions+at+development+time+and+turn+them+off+for+shipping+bits+and+instead+fail+gracefully.

Hope+this+helps.|317677|entityMap|0|LINK|mutability|MUTABLE|url|https://android.googlesource.com/platform/dalvik/%2B/master/docs/embedded-vm-control.html|1|http://milk.com/kodebase/dalvik-docs-mirror/docs/embedded-vm-control.html^0|G|B|0|12|G|1|0|0|0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1E|8|@]|9|@$A|1F|B|1G|1|1H]|$A|1I|B|1J|1|1K]]|C|$]]|$1|D|3|E|5|6|7|1L|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|1M|8|@]|9|@]|C|$]]|$1|H|3|I|5|J|7|1N|8|@]|9|@]|C|$K|L]]|$1|M|3|N|5|6|7|1O|8|@]|9|@]|C|$]]|$1|O|3|P|5|6|7|1P|8|@]|9|@]|C|$]]|$1|Q|3|R|5|6|7|1Q|8|@]|9|@]|C|$]]|$1|S|3|T|5|6|7|1R|8|@]|9|@]|C|$]]|$1|U|3|V|5|6|7|1S|8|@]|9|@]|C|$]]|$1|W|3|X|5|J|7|1T|8|@]|9|@]|C|$K|L]]|$1|Y|3|V|5|6|7|1U|8|@]|9|@]|C|$]]|$1|Z|3|10|5|6|7|1V|8|@]|9|@]|C|$]]|$1|11|3|V|5|6|7|1W|8|@]|9|@]|C|$]]|$1|12|3|13|5|J|7|1X|8|@]|9|@]|C|$K|L]]|$1|14|3|-4|5|6|7|1Y|8|@]|9|@]|C|$]]]|15|$16|$5|17|18|19|C|$1A|1B]]|1C|$5|17|18|19|C|$1A|1D]]]]

See the Embedded VM Control document (raw HTML from the <a href="https://android.googlesource.com/platform/dalvik/+/master/docs/embedded-vm-control.html" rel="noreferrer">source tree</a>, or a <a href="http://milk.com/kodebase/dalvik-docs-mirror/docs/embedded-vm-control.html" rel="noreferrer">nicely formatted</a> copy). 

Basically, the Dalvik VM is set to ignore assertion checks by default, even though the .dex byte code includes the code to perform the check. Checking assertions is turned on in one of two ways: 

(1) by setting the system property "debug.assert" via:

<pre><code>adb shell setprop debug.assert 1
</code></pre>

which I verified works as intended as long as you reinstall your app after doing this, or

(2) by sending the command line argument "--enable-assert" to the dalvik VM which might not be something app developers are likely to be able to do (somebody correct me if I'm wrong here).

Basically, there is a flag that can be set either globally, at a package level, or at a class level which enables assertions at that respective level. The flag is off by default, as a result of which the assertion checks are skipped.

I wrote the following code in my sample Activity:

<pre><code>
public class AssertActivity extends Activity {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.main);
 int x = 2 + 3;
 assert x == 4;
 }
}
</pre></code>

For this code, the dalvik byte code that is generated is (for Android 2.3.3):

<pre><code>
// Static constructor for the class
000318: |[000318] com.example.asserttest.AssertActivity.:()V
000328: 1c00 0300 |0000: const-class v0, Lcom/example/asserttest/AssertActivity; // class@0003
00032c: 6e10 0c00 0000 |0002: invoke-virtual {v0}, Ljava/lang/Class;.desiredAssertionStatus:()Z // method@000c
000332: 0a00 |0005: move-result v0
000334: 3900 0600 |0006: if-nez v0, 000c // +0006
000338: 1210 |0008: const/4 v0, #int 1 // #1
00033a: 6a00 0000 |0009: sput-boolean v0, Lcom/example/asserttest/AssertActivity;.$assertionsDisabled:Z // field@0000
00033e: 0e00 |000b: return-void
000340: 1200 |000c: const/4 v0, #int 0 // #0
000342: 28fc |000d: goto 0009 // -0004

:
:

// onCreate()
00035c: |[00035c] com.example.asserttest.AssertActivity.onCreate:(Landroid/os/Bundle;)V
00036c: 6f20 0100 3200 |0000: invoke-super {v2, v3}, Landroid/app/Activity;.onCreate:(Landroid/os/Bundle;)V // method@0001
000372: 1501 037f |0003: const/high16 v1, #int 2130903040 // #7f03
000376: 6e20 0500 1200 |0005: invoke-virtual {v2, v1}, Lcom/example/asserttest/AssertActivity;.setContentView:(I)V // method@0005
00037c: 1250 |0008: const/4 v0, #int 5 // #5
00037e: 6301 0000 |0009: sget-boolean v1, Lcom/example/asserttest/AssertActivity;.$assertionsDisabled:Z // field@0000
000382: 3901 0b00 |000b: if-nez v1, 0016 // +000b
000386: 1251 |000d: const/4 v1, #int 5 // #5
000388: 3210 0800 |000e: if-eq v0, v1, 0016 // +0008
00038c: 2201 0c00 |0010: new-instance v1, Ljava/lang/AssertionError; // class@000c
000390: 7010 0b00 0100 |0012: invoke-direct {v1}, Ljava/lang/AssertionError;.:()V // method@000b
000396: 2701 |0015: throw v1
000398: 0e00 |0016: return-void

</pre></code>

Notice how the static constructor invokes the method desiredAssertionStatus on the Class object and sets the class-wide variable $assertionsDisabled; also notice that in onCreate(), all of the code to throw java.lang.AssertionError is compiled in, but its execution is contingent upon the value of $assertionsDisabled which is set for the Class object in the static constructor.

It appears that JUnit's Assert class is what is used predominantly, so it is likely a safe bet to use that. The flexibility of the assert keyword is the ability to turn on assertions at development time and turn them off for shipping bits and instead fail gracefully.

Hope this helps.

blocks|key|314670|text|直到我在google上检查了这个问题，我的断言都不起作用，这让我非常恼火……我放弃了简单的断言，转而使用junit断言方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|314671|为了方便起见，我使用：|314672|导入static+junit.framework.Assert.*；|314673|由于静态导入，我可以在稍后编写：|314674|assertTrue(...)；代替Assert.assertTrue(...)；|314675|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|N|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|O|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|P|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|K|$]]

It was bugging the hell out of me, that my assertions didnt work, until I checked the issue out on google... I gave up on simple assertions and will go with junits assertion methods.

For convenience purposes I am using:

import static junit.framework.Assert.*;

Due to the static import I can later write:

assertTrue(...); instead of Assert.assertTrue(...);

blocks|key|312550|text|如果您担心在(或任何其他类路径)中使用JUnit断言发布代码，可以使用ProGuard配置选项'assumenosideeffects'，该选项将剥离一个类路径，假设移除它不会对代码造成任何影响。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|312551|例如：|312552|-assumenosideeffects+junit.framework.Assert+{
*;
}|code-block|syntax|javascript|312553|我有一个通用的调试库，我把我所有的测试方法都放在里面，然后使用这个选项从我发布的应用程序中去掉它。|312554|这也消除了很难发现的字符串被操纵的问题，这些字符串从未在发布代码中使用过。例如，如果您编写了一个调试日志方法，并且在该方法中，您在记录字符串之前检查调试模式，则仍在构造字符串，分配内存，调用该方法，但随后选择不执行任何操作。剥离类，然后完全删除调用，这意味着只要字符串是在方法调用中构造的，它也会消失。|312555|但是，请确保剥离这些行是真正安全的，因为它是在没有检查ProGuard的情况下完成的。删除任何void返回方法都是可以的，但是，如果您从要删除的任何内容中获取任何返回值，请确保您没有将它们用于实际的操作逻辑。|312556|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|T|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

If you're concerned about shipping code with the JUnit asserts in (or any other class path), you can use the ProGuard config option 'assumenosideeffects', which will strip out a class path on the assumption that removing it does nothing to the code.

Eg. 

<pre><code>-assumenosideeffects junit.framework.Assert {
*;
}
</code></pre>

I have a common debug library I put all my testing methods in, and then use this option to strip it from my released apps. 

This also removes the hard to spot problem of strings being manipulated that are never used in release code. For example if you write a debug log method, and in that method you check for debug mode before logging the string, you are still constructing the string, allocating memory, calling the method, but then opting to do nothing. Stripping the class out then removes the calls entirely, meaning as long as your string is constructed inside the method call, it goes away as well.

Make sure it is genuinely safe to just strip the lines out however, as it is done with no checking on ProGuard's part. Removing any void returning method will be fine, however if you are taking any return values from whatever you are removing, make sure you aren't using them for actual operational logic.

blocks|key|3058581|text|为了补充Zulaxia关于剥离Junit+-+Proguard的答案，Junit-Proguard已经是Android+SDK+/Eclipse的一部分，下面的页面将告诉你如何启用它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3058582|http://developer.android.com/guide/developing/tools/proguard.html|offset|length|3058583|此外，上面的配置不适用于最新的默认proguard配置，因为它使用了-dontoptimize标志，必须删除该标志并打开一些优化。|3058584|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|1T|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@$D|Q|E|R|1|S]]|A|$]]|$1|F|3|G|5|6|7|T|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|U|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|C]]]]

To add to Zulaxia's answer on stripping out Junit - Proguard is already part of Android SDK /Eclipse and the following page tells you how to enable it.

<a href="http://developer.android.com/guide/developing/tools/proguard.html" rel="nofollow">http://developer.android.com/guide/developing/tools/proguard.html</a>

Also the above wont work with the latest default proguard configuration because it uses the -dontoptimize flag which must be taken out and some of the optimizations turned on.

blocks|key|317761|text|使用标准Java+assert关键字，例如：|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|317762|assert+a==b;|code-block|syntax|javascript|317763|要使其正常工作，您必须向/system/build.prop添加一行代码，然后重新启动手机：|317764|debug.assert=1|317765|这将在rooted上工作。使用一些能够编辑build.prop的文件管理器(例如X-plore)。|317766|优点:大多数(全部？)Android手机发布时禁用了断言。即使你的代码意外地断言为false，应用程序也不会中断或崩溃。但是，在您开发设备上，您会得到断言异常。|317767|entityMap^0|9|6|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|10|8|@]|D|@]|E|$]]|$1|Q|3|R|5|6|7|11|8|@]|D|@]|E|$]]|$1|S|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|T|$]]

Use standard Java assert keyword, for example:

<pre><code>assert a==b;
</code></pre>

For this to work, you have to add one line to /system/build.prop, and reboot phone:

<pre><code>debug.assert=1
</code></pre>

This would work on rooted phone. Use some file manager capable to edit build.prop (e.g. X-plore).

Pluses: most (all?) Android phones ship with assertions disabled. Even if your code accidentally asserts to false, app won't interrupt or crash.
However, on your development device you'll get assertion exception.

blocks|key|3271919|text|启用断言后，当布尔表达式为false时，assert关键字只抛出一个AssertionError。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3271920|所以，国际海事组织，最好的选择，特别是。如果你不喜欢依赖junit，那就是显式抛出一个AssertionError，如下所示：|3271921|assert+x+==+0+:+"x+=+"+%2B+x;|code-block|syntax|javascript|3271922|上述语句的另一种替代方法是：|3271923|Utils._assert(x+==+0,+"x+=+"+%2B+x);|3271924|其中该方法定义为：|3271925|public+static+void+_assert(boolean+condition,+String+message)+{
++++if+(!condition)+{
++++++++throw+new+AssertionError(message);
++++}
}|3271926|Oracle+java将抛出AssertionError作为可接受的替代方案的recommend文档。|3271927|我猜您可以配置Proguard来剥离生产代码的这些调用。|3271928|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/java/lang/AssertionError.html|1|http://docs.oracle.com/javase/1.4.2/docs/guide/lang/assert.html^0|D|5|K|6|Y|E|Y|E|0|0|17|E|0|0|0|0|0|0|E|E|13|9|1|0|0^^$0|@$1|2|3|4|5|6|7|18|8|@$9|19|A|1A|B|C]|$9|1B|A|1C|B|C]|$9|1D|A|1E|B|C]]|D|@$9|1F|A|1G|1|1H]]|E|$]]|$1|F|3|G|5|6|7|1I|8|@$9|1J|A|1K|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|1L|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1M|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|1N|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|1O|8|@]|D|@]|E|$]]|$1|S|3|T|5|J|7|1P|8|@]|D|@]|E|$K|L]]|$1|U|3|V|5|6|7|1Q|8|@$9|1R|A|1S|B|C]]|D|@$9|1T|A|1U|1|1V]]|E|$]]|$1|W|3|X|5|6|7|1W|8|@]|D|@]|E|$]]|$1|Y|3|-4|5|6|7|1X|8|@]|D|@]|E|$]]]|Z|$10|$5|11|12|13|E|$14|15]]|16|$5|11|12|13|E|$14|17]]]]

When assertions are enabled, the <code>assert</code> keyword simply throws an <a href="http://developer.android.com/reference/java/lang/AssertionError.html"><code>AssertionError</code></a> when the boolean expression is <code>false</code>.

So IMO, the best alternative, esp. if you're averse to depend on junit, is to throw an <code>AssertionError</code> explicitly as shown below:

<pre><code>assert x == 0 : "x = " + x;
</code></pre>

An alternative to the above statement is:

<pre><code>Utils._assert(x == 0, "x = " + x);
</code></pre>

Where the method is defined as:

<pre><code>public static void _assert(boolean condition, String message) {
 if (!condition) {
 throw new AssertionError(message);
 }
}
</code></pre>

The Oracle java docs <a href="http://docs.oracle.com/javase/1.4.2/docs/guide/lang/assert.html">recommend</a> throwing an <code>AssertionError</code> as an acceptable alternative.

I guess you can configure Proguard to strip out these calls for production code.

blocks|key|314742|text|在"Android+In+Practice“中，建议使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|314743|$adb+shell+setprop+dalvik.vm.enableassertions+all|code-block|syntax|javascript|314744|如果此设置未在您的手机上保留，则可以创建具有以下属性的/data/local.prop文件：|314745|dalvik.vm.enableassertions=all|314746|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

In "Android in Practice" it is suggested to use:

<pre><code>$adb shell setprop dalvik.vm.enableassertions all
</code></pre>

if this settings is not persisted on your phone then you can create /data/local.prop file with properties like:

<pre><code>dalvik.vm.enableassertions=all
</code></pre>

blocks|key|314748|text|您可以使用断言，但需要做一些工作才能可靠地使用它们。系统属性debug.assert不可靠；请参阅问题175697、65183、36786和17324。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|314749|一种方法是将每个assert语句转换为任何运行时都可以处理的语句。使用Java编译器前面的源代码预处理器可以做到这一点。例如，请使用以下语句：|314750|assert+x+==+0:+"Failure+message";|code-block|syntax|javascript|314751|对于调试构建，您的预处理器会将上述代码转换为if语句：|314752|{+if(+!(x+==+0)+)+throw+new+AssertionError(+"Failure+message"+);+}|314753|对于生产版本，设置为空语句：|314754|;|314755|请注意，这将在构建时控制断言，而不是运行时(通常的做法)。|314756|我找不到现成的预处理器，所以我使用scripted+one。请参阅处理断言的部分。复制的许可证是here。|314757|entityMap|0|LINK|mutability|MUTABLE|url|https://code.google.com/p/android/issues/detail?id=175697|1|https://code.google.com/p/android/issues/detail?id=65183|2|https://code.google.com/p/android/issues/detail?id=36786|3|https://code.google.com/p/android/issues/detail?id=17324|4|http://reluk.ca/project/waymaker/spec/build/android/Target.js|5|http://reluk.ca/project/waymaker/spec/licence/MIT^0|U|C|1F|6|0|1M|5|1|1S|5|2|1Y|5|3|0|8|6|0|0|M|2|0|0|0|0|0|H|C|4|1C|4|5|0^^$0|@$1|2|3|4|5|6|7|1G|8|@$9|1H|A|1I|B|C]]|D|@$9|1J|A|1K|1|1L]|$9|1M|A|1N|1|1O]|$9|1P|A|1Q|1|1R]|$9|1S|A|1T|1|1U]]|E|$]]|$1|F|3|G|5|6|7|1V|8|@$9|1W|A|1X|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|1Y|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1Z|8|@$9|20|A|21|B|C]]|D|@]|E|$]]|$1|O|3|P|5|J|7|22|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|23|8|@]|D|@]|E|$]]|$1|S|3|T|5|J|7|24|8|@]|D|@]|E|$K|L]]|$1|U|3|V|5|6|7|25|8|@]|D|@]|E|$]]|$1|W|3|X|5|6|7|26|8|@]|D|@$9|27|A|28|1|29]|$9|2A|A|2B|1|2C]]|E|$]]|$1|Y|3|-4|5|6|7|2D|8|@]|D|@]|E|$]]]|Z|$10|$5|11|12|13|E|$14|15]]|16|$5|11|12|13|E|$14|17]]|18|$5|11|12|13|E|$14|19]]|1A|$5|11|12|13|E|$14|1B]]|1C|$5|11|12|13|E|$14|1D]]|1E|$5|11|12|13|E|$14|1F]]]]

You can use assertions, but it takes some work to use them reliably. System property <code>debug.assert</code> is unreliable; see issues <a href="https://code.google.com/p/android/issues/detail?id=175697" rel="nofollow noreferrer">175697</a>, <a href="https://code.google.com/p/android/issues/detail?id=65183" rel="nofollow noreferrer">65183</a>, <a href="https://code.google.com/p/android/issues/detail?id=36786" rel="nofollow noreferrer">36786</a> and <a href="https://code.google.com/p/android/issues/detail?id=17324" rel="nofollow noreferrer">17324</a>.

One method is to translate each <code>assert</code> statement to something any runtime can deal with. Do this with a source preprocessor in front of the Java compiler. For example, take this statement:

<pre><code>assert x == 0: "Failure message";
</code></pre>

For a debug build, your preprocessor would translate the above to an <code>if</code> statement:

<pre><code>{ if( !(x == 0) ) throw new AssertionError( "Failure message" ); }
</code></pre>

For a production build, to an empty statement:

<pre><code>;
</code></pre>

Note that this would control assertions at build time, as opposed to run time (the usual practice).

I could find no ready-made preprocessor, so I <a href="http://reluk.ca/project/waymaker/spec/build/android/Target.js" rel="nofollow noreferrer">scripted one</a>. See the part dealing with assertions. Licence to copy is <a href="http://reluk.ca/project/waymaker/spec/licence/MIT" rel="nofollow noreferrer">here</a>.

I want to use the <a href="https://developer.android.com/reference/junit/framework/Assert.html" rel="nofollow noreferrer">Assert</a> keyword in my android apps to destroy my app in some cases on the emulator, or my device during testing. Is this possible? 

It seems that the emulator just ignores my asserts.

Can I use assert on Android devices?

虚拟机

编译器

Android

Eclipse

Java

我想在我的安卓应用程序中使用关键字，在某些情况下在模拟器上销毁我的应用程序，或者在测试期间销毁我的设备。这个是可能的吗？仿真器似乎忽略了我的断言。

问我可以在Android设备上使用assert吗？
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问我可以在Android设备上使用assert吗？
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