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javaandroidandroid-activitynullpointerexceptionandroid-dialogfragment

How to pass data from Activity to DialogFragment


I know there are some examples on how to pass data from a activity to a dialog (i.e. Bundle or Intent). However, everything I've tried doesn't work. I keep getting NPE's and the "Unable to find explicit activity class" error. Even when I build a superbasic activity with a dialog it doesn't work. What do I have to put in the code to make it work?

MainActivity:

public class MainActivity extends AppCompatActivity {

  Button button;
  String textIWantToSee;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

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

    textIWantToSee = "If this is the text I want to pass form this activity to the Fragment";

    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {


        }
    });
  }
}

Dialog:

public class Dialog extends DialogFragment {

  TextView textView;

  @Override
  public android.app.Dialog onCreateDialog(Bundle savedInstanceState) {

    LayoutInflater inflater = getActivity().getLayoutInflater();
    View v = inflater.inflate(R.layout.dialog_layout, null);

    textView = (TextView) v.findViewById(R.id.textView);

    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    builder.setView(v);

    return builder.create();
  }
}

Update

MainActivity:

public class MainActivity extends AppCompatActivity {

TextView tvIntent;
Button button;
String textIWantToSee;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    tvIntent = (TextView) findViewById(R.id.tvIntent);
    button = (Button) findViewById(R.id.button);

    textIWantToSee = "If this is the text I want to pass form this activity to the Fragment";
    tvIntent.setText(textIWantToSee);

    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            String intent = String.valueOf(tvIntent);
            Intent intentToDialog = new Intent(MainActivity.this, Dialog.class);
            intentToDialog.putExtra("keyForIntent", intent);
            startActivity(intentToDialog); //Here is the exception

        }
    });
}

} Dialog:

public class Dialog extends DialogFragment {

TextView textView;
String intent;

@Override
public android.app.Dialog onCreateDialog(Bundle savedInstanceState) {

    LayoutInflater inflater = getActivity().getLayoutInflater();
    View v = inflater.inflate(R.layout.dialog_layout, null);

    textView = (TextView) v.findViewById(R.id.textView);
    Intent intentFromDialog = new Intent(getActivity().getApplicationContext(),MainActivity.class);
    intent = intentFromDialog.getStringExtra("keyForIntent");
    textView.setText(intent);

    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    builder.setView(v);

    return builder.create();
}

}

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: nl.blogvandetoekomst.passdatafromactivitytodialog, PID: 2947
              android.content.ActivityNotFoundException: Unable to find explicit activity class {nl.blogvandetoekomst.passdatafromactivitytodialog/nl.blogvandetoekomst.passdatafromactivitytodialog.Dialog}; have you declared this activity in your AndroidManifest.xml?
                  at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1794)
                  at android.app.Instrumentation.execStartActivity(Instrumentation.java:1512)
                  at android.app.Activity.startActivityForResult(Activity.java:3917)
                  at android.app.Activity.startActivityForResult(Activity.java:3877)
                  at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:842)
                  at android.app.Activity.startActivity(Activity.java:4200)
                  at android.app.Activity.startActivity(Activity.java:4168)
                  at nl.blogvandetoekomst.passdatafromactivitytodialog.MainActivity$1.onClick(MainActivity.java:36)
                  at android.view.View.performClick(View.java:5198)
                  at android.view.View$PerformClick.run(View.java:21147)
                  at android.os.Handler.handleCallback(Handler.java:739)
                  at android.os.Handler.dispatchMessage(Handler.java:95)
                  at android.os.Looper.loop(Looper.java:148)
                  at android.app.ActivityThread.main(ActivityThread.java:5417)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

Manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="nl.blogvandetoekomst.passdatafromactivitytodialog">

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>


Solution

  • You can create the Dialog directly into your Activity:

    button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
            LayoutInflater inflater = MainActivity.this.getLayoutInflater();
            View v = inflater.inflate(R.layout.dialog_layout, null);
    
            TextView textView = (TextView) v.findViewById(R.id.textView);
            textView.setText(textIWantToSee);
    
            AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
            builder.setView(v);
            builder.show();
    
            }
        });