Not able to update TextView's text in custom dialog box
<p>Please help. I have tried everything but failed every time. I am building an android app where I need to update text of a TextView in dialog box programmatically.
This dialog box is created using a custom layout. Posting code below, Please help in updating value of tv1 to "It's the new text". In XML layout file text was set to "old text".
After I run this program, the value of tv1 in 'dialogabt', is still seen as "old text".</p>

<pre><code>public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button b1 = (Button) findViewById(R.id.b1);

        //generating first dialog box 
        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Dialog dialog1 = new Dialog(MainActivity.this);
                dialog1.requestWindowFeature(Window.FEATURE_NO_TITLE);
                dialog1.setContentView(R.layout.setings);
                dialog1.show();
            }
        });
    }
}
</code></pre>

<p>function to generate the second dialog box and update TextView's text in it</p>

<pre><code>public void abtit(View view) {
    Dialog dialogabt = new Dialog(this);
    dialogabt.requestWindowFeature(Window.FEATURE_NO_TITLE);

    LayoutInflater inflater = this.getLayoutInflater();
    View dialogView = inflater.inflate(R.layout.custom2, null);
    TextView tv1 = (TextView) dialogView.findViewById(R.id.firstapp);

    System.out.println("Going to set new value");
    tv1.setText("Its new text");
    System.out.println("done setting new value");

    dialogabt.setContentView(R.layout.custom2);
    dialogabt.show();
}
</code></pre>

<p><strong>settings.xml</strong></p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="300dp"
    android:layout_height="wrap_content"
    android:orientation="vertical"&gt;

    &lt;TextView
        android:id="@+id/set3"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:onClick="abtit"
        android:text="About app" /&gt;
&lt;/RelativeLayout&gt;
</code></pre>

<p><strong>custom2.xml</strong></p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="315dp"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:background="@drawable/custom_alert2"
    android:orientation="vertical"&gt;

    &lt;TextView
        android:id="@+id/firstapp"
        android:layout_width="wrap_content"
        android:layout_height="100dp"
        android:onClick="openapp2"
        android:text="old text" /&gt;
&lt;/RelativeLayout&gt;
</code></pre>