0

[解决了]

我的代码中有以下结构:

ListView accountListView = (ListView) findViewById(R.id.accountListing);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.list_view_item, R.id.nameTextView, currentAccounts);
accountListView.setAdapter(adapter);

accountListView.performItemClick(null, 0, 0);

currentAccounts 是一个数组,上面有数据。

当我在设置适配器后尝试 performItemClick 时,我得到一个 NullPointerException。

我还覆盖了 OnKeyPress,运行“performItemClick”,它工作正常。

我想知道为什么在设置适配器后尝试执行单击时它不起作用。(经过一些调试,我看到 lastVisiblePosition 是-1)为什么?

[编辑]

使用((ListView)findViewById(R.id.accountListing)).performItemClick(null, 0, 0);工作,除了,如果在设置适配器后立即使用。(查看评论以获取更多信息)

[编辑 2]

堆栈跟踪:

07-24 13:07:56.710: E/AndroidRuntime(9455): FATAL EXCEPTION: main
07-24 13:07:56.710: E/AndroidRuntime(9455): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.app.device/com.app.device.WelcomeActivity}: java.lang.NullPointerException
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2097)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2122)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.app.ActivityThread.access$600(ActivityThread.java:140)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1228)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.os.Handler.dispatchMessage(Handler.java:99)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.os.Looper.loop(Looper.java:137)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.app.ActivityThread.main(ActivityThread.java:4895)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at java.lang.reflect.Method.invokeNative(Native Method)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at java.lang.reflect.Method.invoke(Method.java:511)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:994)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:761)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at dalvik.system.NativeStart.main(Native Method)
07-24 13:07:56.710: E/AndroidRuntime(9455): Caused by: java.lang.NullPointerException
07-24 13:07:56.710: E/AndroidRuntime(9455):     at com.app.device.WelcomeActivity.unselectViews(WelcomeActivity.java:1637)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at com.app.device.WelcomeActivity.access$24(WelcomeActivity.java:1632)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at com.app.device.WelcomeActivity$27.onItemClick(WelcomeActivity.java:1447)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.widget.AdapterView.performItemClick(AdapterView.java:298)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.widget.AbsListView.performItemClick(AbsListView.java:1280)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at com.app.device.WelcomeActivity.UpdateAccountList(WelcomeActivity.java:1653)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at com.app.device.WelcomeActivity.onCreate(WelcomeActivity.java:238)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.app.Activity.performCreate(Activity.java:5163)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
07-24 13:07:56.710: E/AndroidRuntime(9455):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2061)
07-24 13:07:56.710: E/AndroidRuntime(9455):     ... 11 more

提前致谢!

[解决方案]

我试图在该onCreate()方法上执行ItemClick,但屏幕对用户并不完全可见。使用onWindowFocusChanged()工作!Android 文档上的 onWindowFocusChanged()

谢谢大家。

4

3 回答 3

0

您将 null 作为 perfomItemClick 的参数传递,您是否尝试过:

ListView accountListView = (ListView) findViewById(R.id.accountListing);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.list_view_item,         R.id.nameTextView, currentAccounts);
accountListView.setAdapter(adapter);
accountListView.performItemClick(adapter, 0, 0);

希望这可以帮助...

问候!

于 2013-07-23T20:46:49.870 回答
0

我认为您必须将 accountListView 参数传递给 performItemClick 而不是 null 。

于 2013-07-23T21:12:49.737 回答
0

[解决了]

我试图在该onCreate()方法上执行ItemClick,但屏幕对用户并不完全可见。使用onWindowFocusChanged()工作!Android 文档上的 onWindowFocusChanged()

谢谢大家。

于 2013-07-24T17:03:36.853 回答