Question

我正在关注这个tutorial并且我可以让它工作得很好，但是当我尝试更新UI以适应Android 4.2中的新Holo.Light时，应用程序在启动时崩溃，而我不会知道原因。

我一直在寻找一种更新用户界面的方法，但我无法让它发挥作用。

我想知道是否有人可以帮助我？告诉我怎么样？给我一个你知道会起作用的链接？甚至自己动手做？

我收到此错误日志：

11-20 09:50:39.523: I/dalvikvm(1460): threadid=3: reacting to signal 3
11-20 09:50:39.682: I/dalvikvm(1460): Wrote stack traces to '/data/anr/traces.txt'
11-20 09:50:39.892: I/dalvikvm(1460): threadid=3: reacting to signal 3
11-20 09:50:40.003: I/dalvikvm(1460): Wrote stack traces to '/data/anr/traces.txt'
11-20 09:50:40.102: D/AndroidRuntime(1460): Shutting down VM
11-20 09:50:40.102: W/dalvikvm(1460): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
11-20 09:50:40.132: E/AndroidRuntime(1460): FATAL EXCEPTION: main
11-20 09:50:40.132: E/AndroidRuntime(1460): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.androidhive.jsonparsing/com.androidhive.jsonparsing.AndroidJSONParsingActivity}: android.os.NetworkOnMainThreadException
11-20 09:50:40.132: E/AndroidRuntime(1460):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at android.app.ActivityThread.access$600(ActivityThread.java:123)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at android.os.Handler.dispatchMessage(Handler.java:99)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at android.os.Looper.loop(Looper.java:137)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at android.app.ActivityThread.main(ActivityThread.java:4424)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at java.lang.reflect.Method.invokeNative(Native Method)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at java.lang.reflect.Method.invoke(Method.java:511)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at dalvik.system.NativeStart.main(Native Method)
11-20 09:50:40.132: E/AndroidRuntime(1460): Caused by: android.os.NetworkOnMainThreadException
11-20 09:50:40.132: E/AndroidRuntime(1460):     at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at java.net.InetAddress.lookupHostByName(InetAddress.java:391)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at java.net.InetAddress.getAllByNameImpl(InetAddress.java:242)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at java.net.InetAddress.getAllByName(InetAddress.java:220)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at com.androidhive.jsonparsing.JSONParser.getJSONFromUrl(JSONParser.java:38)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at com.androidhive.jsonparsing.AndroidJSONParsingActivity.onCreate(AndroidJSONParsingActivity.java:53)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at android.app.Activity.performCreate(Activity.java:4465)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
11-20 09:50:40.132: E/AndroidRuntime(1460):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
11-20 09:50:40.132: E/AndroidRuntime(1460):     ... 11 more
11-20 09:50:40.392: I/dalvikvm(1460): threadid=3: reacting to signal 3
11-20 09:50:40.412: I/dalvikvm(1460): Wrote stack traces to '/data/anr/traces.txt'
11-20 09:50:40.791: I/dalvikvm(1460): threadid=3: reacting to signal 3
11-20 09:50:40.962: I/dalvikvm(1460): Wrote stack traces to '/data/anr/traces.txt'

Answer 1

您正在主线程上进行网络呼叫。 Android 4.2上不允许这样做，对于允许这样做的早期版本来说这是一个非常糟糕的主意。我在博客上发表了关于在http://blog.stylingandroid.com/archives/833上移动主线程的网络和其他大量呼叫的各种机制。

如果没有看到您的代码，我就无法开始建议哪种方法适合您使用，但希望我的文章中的信息可以帮助您确定正确的方法。

Answer 2

这个问题有两个解决方案。

1）不要在Main UIThread，Use Async Task中编写网络调用。

2）在setContentView（R.layout.activity_main）之后将下面的代码写入MainActivity文件;

if (android.os.Build.VERSION.SDK_INT > 9) {
    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy);
}

将import语句放到你的java文件中。

import android.os.StrictMode;

并查看以下链接以获取更多信息。

Twitter connect error

更新旧的android项目

2 个答案: