IllegalArgumentException:快速切换ActionBar Tabs时,没有为片段的id找到视图

Question

我正在为平板电脑开发Android应用,而不是使用兼容性库.

只有一个Activity,它使用带有3个选项卡的ActionBar.在TabListener中,我使用setContentView加载特定于该选项卡的布局,然后将相关片段添加到其框架中.这几乎与我想要的完全一样,除非你在选项卡之间切换得足够快,应用程序就会崩溃.

我使用三星Galaxy Tab作为我的调试设备,切换标签非常快.以正常速度,我可以在它们之间来回切换,页面立即加载.问题是当我在选项卡之间进行超级切换时.

起初我得到了一个

IllegalStateException: Fragment not added

如下所示:http: //code.google.com/p/android/issues/detail？ id = 17029根据onTabUnselected中使用try/catch块的建议,我使应用程序更加强大,但导致手头的问题:

IllegalArgumentException: No view found for id 0x... for fragment ...

我没有在网上找到任何其他有同样问题的案例,所以我担心我可能会做一些不受支持的事情.同样,我想要做的是在一个Activity中使用3种不同的布局 - 当你单击一个选项卡时,监听器将调用setContentView来更改布局,然后添加片段.除非您开始在标签之间积极切换,否则它的工作效果非常好

我从以下方面得到了这个想法:http://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/app/FragmentTabs.html 而不是TabListener保留对一个片段的引用,我有一系列的.此外,我没有使用附加/分离,因为这些只是在API 13中添加.

我的理论是setContentView还没有完成创建视图,这就是FragmentTransaction无法添加它们的原因,或者当选择另一个选项卡并调用setContentView时,为一个选项卡添加片段,从而破坏另一组视图.

我试图破解一些东西来减慢标签切换速度,但没有到达任何地方.

这是我的TabListener的代码:

private class BTabListener<T extends Fragment> implements ActionBar.TabListener{

    private int mLayout;
    private Fragment[] mFrags;
    private TabData mTabData;
    private Activity mAct;
    private boolean mNoNewFrags;


    public BTabListener(Activity act, int layout, TabData td, boolean frags){
        mLayout = layout;
        mTabData = td;
        mAct = act;
        mNoNewFrags = frags;

        mFrags = new Fragment[mTabData.fragTags.length];
        for(int i=0; i<mFrags.length; i++){
            //on an orientation change, this will find the fragments that were recreated by the system
            mFrags[i] = mAct.getFragmentManager().findFragmentByTag(mTabData.fragTags[i]);
        }

    }

    @Override
    public void onTabReselected(Tab tab, FragmentTransaction ft) {

    }

    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        //this gets called _after_ unselected
        //note: unselected wont have been called after an orientation change!
        //we also need to watch out because tab 0 always gets selected when adding the tabs

        //set the view for this tab
        mAct.setContentView(mLayout);

        for(int i=0; i<mFrags.length; i++){
            //this will be null when the tab is first selected
            if(mFrags[i]==null ){
                mFrags[i] = Fragment.instantiate(GUITablet.this, mTabData.classes[i].getName());                    
            }

            //if there was an orientation change when we were on this page, the fragment is already added
            if(!mNoNewFrags || mDefaultTab!=tab.getPosition()){
                ft.add(mTabData.containterIDs[i], mFrags[i], mTabData.fragTags[i]);
            }
        }
        mNoNewFrags = false;


    }

    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
        // this gets called when another tab is selected, before it's onSelected method 

        for(Fragment f : mFrags){
            try{ //extra safety measure
                ft.remove(f);
            }catch(Exception e){
                e.printStackTrace();
                System.out.println("unselect couldnt remove");
            }
        }
    }

}

最后,堆栈跟踪:

09-29 01:53:08.200: ERROR/AndroidRuntime(4611): java.lang.IllegalArgumentException: No view found for id 0x7f0b0078 for fragment Fraggle{40ab2230 #2 id=0x7f0b0078 dummy2}
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:729)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:926)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at android.app.BackStackRecord.run(BackStackRecord.java:578)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1226)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at android.app.FragmentManagerImpl$1.run(FragmentManager.java:374)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at android.os.Handler.handleCallback(Handler.java:587)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at android.os.Handler.dispatchMessage(Handler.java:92)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at android.os.Looper.loop(Looper.java:132)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at android.app.ActivityThread.main(ActivityThread.java:4028)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at java.lang.reflect.Method.invokeNative(Native Method)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at java.lang.reflect.Method.invoke(Method.java:491)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:844)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
09-29 01:53:08.200: ERROR/AndroidRuntime(4611):     at dalvik.system.NativeStart.main(Native Method)

谢谢!!

Answer 1

好的,找到了解决这个问题的方法:

将对片段的引用放在布局文件中,并在try/catch块中的onTabSelected中包围setContentView调用.

异常处理照顾它!