Fer Fer - 3 days ago 5
Android Question

findViewById() returns null - tried EVERYTHING

I give up... not even my professor knows why this is happening.

The problem is: No matter where or how I call for this layout's components, they always return null.


LAYOUT: search_layout. 2 EdiText and 2 TextView children.


RUNTIME: setView(inflater.inflate(R.layout.search_layout, null)) // works fine, it displays the layout inside the dialog, yet, children are always returned as null by findViewById(R.id.some_search_layout_children)


EXCEPTION: Parsing exception of the XML, as resource not found, hence null.

TRIED: Cleaned my project around 1024 times, tried to implement another class for my dialog box, same result, called findViewById as a member of my main activity, inside the method initSearch() and inside an anonymous implementation of OnClickListener for my dialog, SAME RESULT. Broke the children into independent views and programmatically called them:

TextView text = (TextView) findResourceById(R.id.new_independant_textview); // same result


I think I tried everything.

This is my Code:

public class Xyz extends Activity {
public void onCreate(...) { // some listener will trigger initSearch() }

private void initSearch() {
AlertDialog.Builder searchDialog = new AlertDialog.Builder(this);
LayoutInflater inflater = this.getLayoutInflater();
searchDialog.setTitle("Search Photos");
searchDialog.setMessage("Specify tag and value...");
// R.layout.search_dialog is my custom layour, it displays fine, it works.
searchDialog.setView(inflater.inflate(R.layout.search_dialog, null));
EditText tagText = (EdiText) findViewById(R.id.tagField); // WILL RETURN NULL
searchDialog.setPositiveButton( ... ) ...
searchDialog.show();
}


Now, when I do:

EditText text = (EditText) findViewById(R.id.tagField); // returns null, ALWAYS
// no matter HOW, WHERE, global, local final, etc, it just returns null.


Here is the XML of my custom layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/search_dialog"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="@+id/tagText"
android:padding="7dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="14sp"
android:text="@string/tag" />
<EditText
android:id="@+id/tagField"
android:padding="7dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="text"/>
<TextView
android:id="@+id/valueText"
android:padding="7dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="14sp"
android:text="@string/value" />
<EditText
android:id="@+id/valueField"
android:padding="7dp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="text"/>
</LinearLayout>


This is my R.java file:

public static final class id {
public static final int action_settings=0x7f0a0011;
public static final int add_album=0x7f0a0001;
public static final int add_photo=0x7f0a000d;
public static final int albums_list=0x7f0a0003;
public static final int delete_album=0x7f0a000b;
public static final int exit_finder=0x7f0a000f;
public static final int new_directory=0x7f0a000e;
public static final int open_album=0x7f0a000a;
public static final int photos_grid=0x7f0a0000;
public static final int rename_album=0x7f0a000c;
public static final int search_dialog=0x7f0a0004;
public static final int search_icon=0x7f0a0002;
public static final int splash_rutgers=0x7f0a0009;
public static final int tagField=0x7f0a0006; // problematic
public static final int tagText=0x7f0a0005; / problematic
public static final int terminate_app=0x7f0a0010;
public static final int valueField=0x7f0a0008; // problematic
public static final int valueText=0x7f0a0007; // problematic
}


Thanks for your help, happy hunting.

Answer

Calling findViewById() will search for views within your Activity's layout and not your dialog's view. You need to call findViewById() on the specific View that you set as your dialog's layout.

Try this

private void initSearch() {
    AlertDialog.Builder searchDialog = new AlertDialog.Builder(this);
    LayoutInflater inflater = this.getLayoutInflater();
    searchDialog.setTitle("Search Photos");
    searchDialog.setMessage("Specify tag and value...");
    // R.layout.search_dialog is my custom layour, it displays fine, it works. 
    View dialogView = inflater.inflate(R.layout.search_dialog, null);
    searchDialog.setView(dialogView);
    EditText tagText = (EdiText) dialogView.findViewById(R.id.tagField); 
    searchDialog.setPositiveButton( ... ) ...
    AlertDialog myAlert = searchDialog.create(); //returns an AlertDialog from a Builder.
    myAlert.show();
}

Notice how I'm inflating the view and storing it in a View named dialogView. Then, to find your EditText named tagField, I'm using dialogView.findViewById(R.id.tagField);

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