2

我正在尝试通过使用它来显示来自 Web 服务的一张图像。它工作正常。如果我用 2-3 版本的 android 版本测试我的项目，它工作正常。但它不支持超过 4.0 及更高版本。为什么？

如何克服这个问题？

以下是我的代码，

Bitmap bitmap = BitmapFactory.decodeStream((InputStream)new URL(img_url).getContent());
imgvw.setImageBitmap(bitmap);

日志猫

03-23 14:59:17.696: I/System.out(386): Intent { cmp=com.example.png/.tab_cameraActivity }
03-23 14:59:17.696: I/System.out(386): LB 3
03-23 14:59:17.716: D/AndroidRuntime(386): Shutting down VM
03-23 14:59:17.716: W/dalvikvm(386): threadid=1: thread exiting with uncaught exception (group=0x40014760)
03-23 14:59:17.736: E/AndroidRuntime(386): FATAL EXCEPTION: main
03-23 14:59:17.736: E/AndroidRuntime(386): java.lang.RuntimeException: Unable to start  activity ComponentInfo{com.example.png/com.example.png.tab_cameraActivity}: android.os.NetworkOnMainThreadException
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1736)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.app.ActivityThread.startActivityNow(ActivityThread.java:1577)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:130)
03-23 14:59:17.736: E/AndroidRuntime(386):  at  android.app.LocalActivityManager.startActivity(LocalActivityManager.java:342)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:680)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.widget.TabHost.setCurrentTab(TabHost.java:349)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:149)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:556)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.view.View.performClick(View.java:3100)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.view.View$PerformClick.run(View.java:11644)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.os.Handler.handleCallback(Handler.java:587)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.os.Handler.dispatchMessage(Handler.java:92)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.os.Looper.loop(Looper.java:126)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.app.ActivityThread.main(ActivityThread.java:3997)
03-23 14:59:17.736: E/AndroidRuntime(386):  at java.lang.reflect.Method.invokeNative(Native Method)
03-23 14:59:17.736: E/AndroidRuntime(386):  at java.lang.reflect.Method.invoke(Method.java:491)
03-23 14:59:17.736: E/AndroidRuntime(386):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
03-23 14:59:17.736: E/AndroidRuntime(386):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
03-23 14:59:17.736: E/AndroidRuntime(386):  at dalvik.system.NativeStart.main(Native Method)
03-23 14:59:17.736: E/AndroidRuntime(386): Caused by: android.os.NetworkOnMainThreadException
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1077)
03-23 14:59:17.736: E/AndroidRuntime(386):  at java.net.InetAddress.lookupHostByName(InetAddress.java:481)
03-23 14:59:17.736: E/AndroidRuntime(386):  at java.net.InetAddress.getAllByNameImpl(InetAddress.java:281)
03-23 14:59:17.736: E/AndroidRuntime(386):  at java.net.InetAddress.getAllByName(InetAddress.java:249)
03-23 14:59:17.736: E/AndroidRuntime(386):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>(HttpConnection.java:69)
03-23 14:59:17.736: E/AndroidRuntime(386):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>(HttpConnection.java:48)
03-23 14:59:17.736: E/AndroidRuntime(386):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection$Address.connect(HttpConnection.java:304)
03-23 14:59:17.736: E/AndroidRuntime(386):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnectionPool.get(HttpConnectionPool.java:89)
03-23 14:59:17.736: E/AndroidRuntime(386):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getHttpConnection(HttpURLConnectionImpl.java:292)
03-23 14:59:17.736: E/AndroidRuntime(386):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.makeConnection(HttpURLConnectionImpl.java:274)
03-23 14:59:17.736: E/AndroidRuntime(386):  at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:217)
 03-23 14:59:17.736: E/AndroidRuntime(386):     at org.ksoap2.transport.ServiceConnectionSE.connect(ServiceConnectionSE.java:76)
03-23 14:59:17.736: E/AndroidRuntime(386):  at org.ksoap2.transport.HttpTransportSE.call(HttpTransportSE.java:153)
03-23 14:59:17.736: E/AndroidRuntime(386):  at org.ksoap2.transport.HttpTransportSE.call(HttpTransportSE.java:95)
03-23 14:59:17.736: E/AndroidRuntime(386):  at com.example.png.tab_cameraActivity.getImagesDetails(tab_cameraActivity.java:73)
03-23 14:59:17.736: E/AndroidRuntime(386):  at   com.example.png.tab_cameraActivity.onCreate(tab_cameraActivity.java:57)
03-23 14:59:17.736: E/AndroidRuntime(386):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1048)
 03-23 14:59:17.736: E/AndroidRuntime(386):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1700)
03-23 14:59:17.736: E/AndroidRuntime(386):  ... 18 more
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2 回答 2

2

你得到了例外。

NetworkOnMainThreadException：当应用程序尝试在其主线程上执行网络操作时引发的异常。

所以你必须使用AsyncTask。

这是 AsyncTask 的示例。

http://android-developers.blogspot.in/2009/05/painless-threading.html

于 2013-03-23T09:45:00.400 回答
1

您可能会在 UI 线程中执行此代码。这在 Android HoneyComb 及更高版本中是被禁止的。您应该考虑使用 AsyncTask 或 Android Service 来执行此请求。可以使用不同的选项来帮助您。作为RoboSpice的贡献者，我相信这个库会有所帮助。

于 2013-03-23T07:11:44.917 回答