Android: findviewbyid: finding view by id when vie

2019-01-21 22:18发布

I have an activity MyActivity that extends from MapActivity. In the .xml file containing the layout I can only include the MapView

<com.google.android.maps.MapView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/trail_map_view"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:clickable="true"
    android:apiKey="key"
/>

However I do need to find another view that is located in another .xml file. Unfortunately, findViewById returns null. How can I get the view I am looking for?

Thanks a lot!

4条回答
爱情/是我丢掉的垃圾
2楼-- · 2019-01-21 22:29

Thanks for commenting, I understand what you mean but I didn't want to check old values. I just wanted to get a pointer to that view.

Looking at someone else's code I have just found a workaround, you can access the root of a layout using LayoutInflater.

The code is the following, where this is an Activity:

final LayoutInflater factory = getLayoutInflater();

final View textEntryView = factory.inflate(R.layout.landmark_new_dialog, null);

landmarkEditNameView = (EditText) textEntryView.findViewById(R.id.landmark_name_dialog_edit);

You need to get the inflater for this context, access the root view through the inflate method and finally call findViewById on the root view of the layout.

Hope this is useful for someone! Bye

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Evening l夕情丶
3楼-- · 2019-01-21 22:33

try:

Activity parentActivity = this.getParent();
if (parentActivity != null)
{
    View landmarkEditNameView = (EditText) parentActivity.findViewById(R.id. landmark_name_dialog_edit);
}
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Deceive 欺骗
4楼-- · 2019-01-21 22:34

I have changed in my activity but effected. Here is my code:

View layout = getLayoutInflater().inflate(R.layout.list_group,null);
        try {
            LinearLayout linearLayout = (LinearLayout) layout.findViewById(R.id.ldrawernav);
            linearLayout.setBackgroundColor(Color.parseColor("#ffffff"));
        }
        catch (Exception e) {

        }

    }
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Luminary・发光体
5楼-- · 2019-01-21 22:34

It's impossible. You can only find and access views that are currently running. If you want to check the value of ex. TextView used in previus activity you must save the value is SharedPreferences, database, file or pass by Intent.

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