Android Master Detail Flow - Select first item in list on tablet only

问题

I created a new app relying on the default "Master Detail Flow" template, chosen in the "New Project..." dialog of Android Studio. Then I adapted the application to fit my needs and my data. Works like a charm on handhelds and tablets.

The only thing I want to achive ist to autoselect the first item in the list, showing the detail view and setting the list item as selected.

In the "ItemListFragment" I called the "onListItemClick(...)" method in the overwritten "onStart()" method. This had following behaviours:

When rotating the device, the first item in the list gets selected (not the previously selected one)
The list item does not get marked as selected in the list

Could someone point me in the right direction on how to achieve this. Because I only want this behaviour in "Tablet-Mode" I guess I have to put it into the ItemListActivity?

Thanks

EDIT: This is my "onCreate" method of the "ItemListActivity"

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_item_list);
    if (findViewById(R.id.item_detail_container) != null) {
        mTwoPane = true;
        ((ItemListFragment) getFragmentManager()
                .findFragmentById(R.id.item_list))
                .setActivateOnItemClick(true);
    }
}

回答1:

You could resolve this by removing the onListItemClick(...) call in the onStart(...) of ItemListFragment and instead adding this below snippet to the end of setActivateOnItemClick(...):

    // If on dual-pane view, pre-select the first item from the chapter list
    if (activateOnItemClick && mActivatedPosition == ListView.INVALID_POSITION) {
        getListView().performItemClick(getListView(), 0, getListView().getItemIdAtPosition(0));
    }

Also, add this one line of code if it is not already there in onListItemClick(...) in ItemListFragment:

    mActivatedPosition = position;

Please check the diff on the file ChapterListFragment from these commits yesterday on my GH repo to get a little more context to my solution - https://github.com/floydpink/BhagavadGita/compare/047de35c39f01c6341a7f677aa5b7cc47a7144a3...b1b45d15cd68290e2ebe909ca920bd7aefd2805e#diff-1

Hope this helps

来源：https://stackoverflow.com/questions/24798838/android-master-detail-flow-select-first-item-in-list-on-tablet-only

标签

android

listview

orientation

tablet