Android的/的ListView：选择loading DATAS后第一项 [英] Android/ListView : Select first item after loading datas

问题描述

修改
我必须告诉你，我的ListView是由AsyncTask的填充。

EDIT I must tell you that my ListView is populate by an AsyncTask.

当我在onPostExecute方法做的code以下正常工作：

The code below works fine when I do in onPostExecute method :

synchronized (mListView) {
            if(mFeeds==null || mFeeds.size()==0){
                Utils.Log("mFeeds empty");
                _this.setListShown(false);
            }else{
                Utils.Log("mFeeds Full");
                _this.setListShown(true);
                mListView.setAdapter(new ListFeedsAdapter(mActivity,mFeeds));
                mListView.notifyAll();

                NewsFeedsDetailViewPagerFragment fragment = (NewsFeedsDetailViewPagerFragment) getFragmentManager()
                        .findFragmentById(R.id.feeddetailViewPagerFragment);

                if(fragment!=null){
                    mListView.performItemClick(null, 0, mListView.getFirstVisiblePosition());

                }
            }

        }

该项目被点击，我的详细视图是填充...

The item is clicked and my detail view is populate...

我尝试我的片段改变改变了ListFragment但没有...

I try to change my Fragment to a ListFragment but nothing changed...

编辑结束

有关我的应用程序，我在屏幕左侧的ListView并在合适的一个细节视图中创建（平板）的用户界面。
我想自动选择负载DATAS后的第一个项目，并查看详细信息。

For my application, I created an UI (for tablet) with ListView at left screen and a detail view at the right. I would like to automatically select the first item after loading datas, and view the detail.

我能够通过调用做到这一点 mListView.performItemClick（NULL，0，mListView.getFirstVisiblePosition（））; 和

I am able to do this by calling mListView.performItemClick(null, 0, mListView.getFirstVisiblePosition()); and

mListView.setOnItemClickListener(new OnItemClickListener() {

    @Override
    public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
            long arg3) {
    // TODO Auto-generated method stub

    NewsFeedsDetailViewPagerFragment fragment = (NewsFeedsDetailViewPagerFragment)
            getFragmentManager().findFragmentById(R.id.feeddetailViewPagerFragment);
    if(fragment!=null){
        fragment.setFeedDetail(mFeeds, arg2);
    }
});

现在，我想要做的就是要突出Gmail等应用程序的平板电脑中的第一项。
我用一个选择的背景上的每一行，如：

Now, what I want to do is to highlight the first item like Gmail application for tablet. I use a selector background on each row like :

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/selected_item_background" android:state_activated="true"/>
    <item android:drawable="@drawable/pressed_item_background" android:state_activated="false" android:state_pressed="true"/>
    <item android:drawable="@drawable/pressed_item_background" android:state_focused="true"/>
    <item android:drawable="@drawable/unselected_item_background"/>
</selector>

当我使用 mListView.getChildAt（ARG2）.setActivated（真）; 在onItemClick监听器，我有一个NullPointerException异常，因为 mListView.getChildAt （ARG2）为空，只有当我把perforItemClick。如果我只是注释此行，然后单击某行，此行的亮点是在Gmail应用程序。

When I use mListView.getChildAt(arg2).setActivated(true); in the onItemClick listener, I have a NullPointerException because mListView.getChildAt(arg2) is null, only if I keep the perforItemClick. If I just comment this line, and click on a row, this row is highlight as in Gmail application.

您可以帮我，告诉我什么，我做错了吗？

Can you help me and tell me what I'm doing wrong ?

感谢提前

推荐答案

我找到了解决我的问题，我张贴在这里解决，如果有一个开发商是在同样的情况。

I found a solution to my problem and I post here the solution if there is a developer that is in the same situation.

我创造了我的适配器方法，它标志至极位置必须被激活，并在我的getView方法，我只是当前位置比较标志并激活与否行：

I created a method in my adapter that flag wich position must be activated and in my getView method, I just compare the current position to the flag and activate or not the row :

((ListFeedsAdapter) mListView.getAdapter()).setItemSelected(mOldPosition);

和在适配器：

private int mItemSelected = -1 ;
public void setItemSelected(int position){
mItemSelected=position;
}

public View getView(int position, View convertView, ViewGroup parent){
       //some code ....
    if(mItemSelected==position){
        convertView.setActivated(true);
    }else{
        convertView.setActivated(false);
    }
}

感谢您！

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