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我对 ViewPager 有疑问。当 Activity 启动时，我运行 AsyncTask 从服务器下载数据，我调用的是带有ViewPageIndicator.TabPageIndicatorpager.setAdapter(currentPager) currentPager标签的空 Fragment 

pager = (ViewPager) findViewById(R.id.pager);
        pager.setAdapter(currentPager);

indicator = (TabPageIndicator) findViewById(R.id.indicator);
        indicator.setViewPager(pager);

当 AsyncTask 完成我调用的下载数据pager.setAdapter(currentPager);并且前 2 页为空时，其他页面都可以。如何首先刷新到具有适当数据的页面？我不能调用 setContentViewpager.setAdapter(currentPager);因为我有一个 NULL 指针

E/AndroidRuntime(23263): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.windmobile.rbt.android/com.windmobile.rbt.android.category.CategoryActivity}: java.lang.IllegalStateException: ViewPage
r does not have adapter instance.
E/AndroidRuntime(23263):        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
E/AndroidRuntime(23263):        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
E/AndroidRuntime(23263):        at android.app.ActivityThread.access$2200(ActivityThread.java:119)
E/AndroidRuntime(23263):        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
E/AndroidRuntime(23263):        at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime(23263):        at android.os.Looper.loop(Looper.java:123)
E/AndroidRuntime(23263):        at android.app.ActivityThread.main(ActivityThread.java:4363)
E/AndroidRuntime(23263):        at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(23263):        at java.lang.reflect.Method.invoke(Method.java:521)
E/AndroidRuntime(23263):        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
E/AndroidRuntime(23263):        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
E/AndroidRuntime(23263):        at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime(23263): Caused by: java.lang.IllegalStateException: ViewPager does not have adapter instance.
E/AndroidRuntime(23263):        at com.viewpagerindicator.TabPageIndicator.setViewPager(TabPageIndicator.java:205)
E/AndroidRuntime(23263):        at com.windmobile.rbt.android.category.CategoryActivity.onCreate(CategoryActivity.java:115)
E/AndroidRuntime(23263):        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
E/AndroidRuntime(23263):        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
E/AndroidRuntime(23263):        ... 11 more
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1 回答 1

1

不要重置您的适配器。而不是这样，当您的异步任务完成时更新适配器中的数据源，然后调用notifyDataSetChanged()适配器。

于 2012-11-20T08:56:14.980 回答