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