title: button null object reference
body: <p>i have custom alert dialog with two button inside. but each button have error null object reference, i want to make my relativelayout clickable and here is my java code :</p>
  
  <pre><code>RelativeLayout relaCamera;
  RelativeLayout relaGallery;
  
  relaCamera = findViewById(R.id.relaCameraIntent);
  relaGallery = findViewById(R.id.relaGalleryIntent);
  ......
  ......
  private void pickFromGallery() {
      LayoutInflater layoutInflater = LayoutInflater.from(this);
      View view = layoutInflater.inflate(R.layout.upload_video_options, null);
  
      final AlertDialog alertD = new AlertDialog.Builder(this).create();
  
      relaCamera.setOnClickListener(new View.OnClickListener() { // error here
          public void onClick(View v) {
  
              Intent intent = new Intent();
              intent.setTypeAndNormalize("video/*");
              intent.setAction(Intent.ACTION_GET_CONTENT);
              intent.addCategory(Intent.CATEGORY_OPENABLE);
              startActivityForResult(Intent.createChooser(intent, "Select Video"), REQUEST_GET_VIDEO);
  
          }
      });
  
      relaGallery.setOnClickListener(new View.OnClickListener() {// error here
          public void onClick(View v) {
  
              Intent takeVideoIntent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
              if (takeVideoIntent.resolveActivity(getPackageManager()) != null) {
                  startActivityForResult(takeVideoIntent, REQUEST_VIDEO_CAPTURE);
              }
  
          }
      });
  
      alertD.setView(view);
  
      alertD.show();
  }
  </code></pre>
  
  <p>here is my upload_video_options.xml for customize the alert dialog:</p>
  
  <pre><code>&lt;RelativeLayout
          android:id="@+id/relaCameraIntent"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:layout_marginBottom="10dp"
          android:layout_marginLeft="10dp"
          android:layout_marginTop="20dp"
          android:clickable="true"
          android:gravity="center_horizontal"
          android:orientation="horizontal"&gt;
  &lt;RelativeLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:gravity="center_horizontal"
          android:id="@+id/relaGalleryIntent"
          android:clickable="true"
          android:layout_marginBottom="10dp"
          android:layout_marginTop="10dp"
          android:orientation="horizontal"&gt;
  </code></pre>