CODEWITHSUNDEEP
androidandroid-intent
Shri
Shri

Reputation: 159

How to restore values of a activity when i move to next activity and come back again?

I want the values of edit text restored when user comes back to my first activity? Please help me out.

Thanks in advance

this is my first activity code for getting user values in edit text

public class IntentActivity extends Activity {
EditText ed1, ed2;
float ed1_val, ed2_val;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    ed1 = (EditText) findViewById(R.id.editText1);
    ed2 = (EditText) findViewById(R.id.editText2);
    Button next = (Button) findViewById(R.id.button1);

    next.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            Intent intent = new Intent(getApplicationContext(),
                    Second_activity.class);
            startActivity(intent);
        }
    });
}

/** Called when the activity is first created. */
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
    super.onSaveInstanceState(savedInstanceState);

    ed1_val = Float.parseFloat(ed1.getText().toString());
    ed2_val = Float.parseFloat(ed2.getText().toString());

    Log.v("TAG", "inside saved instance");
    savedInstanceState.putFloat("ed1", +ed1_val);
    savedInstanceState.putFloat("ed2", +ed2_val);
}

@Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);

    Log.v("TAG", "inside on restore");
    float ed_val = savedInstanceState.getFloat("ed1");
    float ed2_val = savedInstanceState.getFloat("ed2");

    ed1.setText("" + ed_val);
    ed2.setText("" + ed2_val);
    }
}

this is my second activity code

public class Second_activity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.second_xml);

    Button back = (Button) findViewById(R.id.button1);
    back.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            Intent intent = new Intent(getApplicationContext(),
                    IntentActivity.class);
            startActivity(intent);
            }
        });
    }
}

Upvotes: 0

Views: 7186

Answers (6)

Patrick McCullagh
Patrick McCullagh

Reputation: 41

Its easy if you do not need to send data back to the first activity. How do send back data without using an intent.

Upvotes: 0

Samuil Yanovski
Samuil Yanovski

Reputation: 2867

You don't need neither onSaveInstanceState nor onRestoreInstanceState. Just call finish in the onClick listener for the button in the second Activity:

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class IntentActivity extends Activity {
    EditText ed1, ed2;
    float ed1_val, ed2_val;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        ed1 = (EditText) findViewById(R.id.editText1);
        ed2 = (EditText) findViewById(R.id.editText2);
        Button next = (Button) findViewById(R.id.button1);

        next.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                Intent intent = new Intent(getApplicationContext(),
                        Second_activity.class);
                startActivity(intent);
            }
        });
    }

}

This is the second one:

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class Second_activity extends Activity {
    // TODO Auto-generated method stub
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.second_xml);

        Button back = (Button) findViewById(R.id.button1);
        back.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                finish();
            }
        });
    }
}

That way you are resuming the previous Activity instead of starting new one. If you need to pass data between them you could use startActivityForResult / onActivityResult and setResult methods:

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class IntentActivity extends Activity {
    private static final int GET_VALUES_REQUEST_ID = 1;
    public static final String FIRST_VALUE_ID = "first_value_id";
    public static final String SECOND_VALUE_ID = "second_value_id";
    private static final float DEFAULT_VALUE = 0;

    EditText ed1, ed2;
    float ed1_val, ed2_val;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        ed1 = (EditText) findViewById(R.id.editText1);
        ed2 = (EditText) findViewById(R.id.editText2);
        Button next = (Button) findViewById(R.id.button1);

        next.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                Intent intent = new Intent(getApplicationContext(),
                        Second_activity.class);
                startActivityForResult(intent, GET_VALUES_REQUEST_ID);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch (requestCode) {
        case GET_VALUES_REQUEST_ID: {
            if (Activity.RESULT_OK == resultCode) {
                ed1_val = data.getFloatExtra(FIRST_VALUE_ID, DEFAULT_VALUE);
                ed2_val = data.getFloatExtra(SECOND_VALUE_ID, DEFAULT_VALUE);
                setValues();
            }
            break;
        }
        }
        super.onActivityResult(requestCode, resultCode, data);
    }


    protected void setValues() {
        ed1.setText(Float.toString(ed1_val));
        ed2.setText(Float.toString(ed2_val));
    }

}

The second activity could be something like that:

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class Second_activity extends Activity {
    // TODO Auto-generated method stub
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.second_xml);

        Button back = (Button) findViewById(R.id.button1);
        back.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                Intent data = new Intent();
                data.putExtra(IntentActivity.FIRST_VALUE_ID, 324f);
                data.putExtra(IntentActivity.SECOND_VALUE_ID, 32234f);
                setResult(Activity.RESULT_OK, data);
                finish();
            }
        });
    }
}

This is a very basic example so I just hardcoded some return values - please implement something more meaningful. Beside that you could avoid using underscores as word separator in class names - camel case is much more accepted as name convention.

Upvotes: 1

Android Killer
Android Killer

Reputation: 18489

you can go for overriding protected void onSaveInstanceState(Bundle outState) and protected void onRestoreInstanceState(Bundle savedInstanceState)

Here is an example

Remember it will work when you will not finish your previous activity.Do this in your first activity.

Upvotes: 1

Relsell
Relsell

Reputation: 771

You are starting a new activity by pressing back button on Second Activity. The new activity instance is not the previous one that has started the Second Activity hence onRestoreInstanceState callback is not getting called.

Upvotes: 0

Ashwin N Bhanushali
Ashwin N Bhanushali

Reputation: 3882

just finish the second activity don't start it via intent. When you finish the second activity first activity will be automatically resumed,

Upvotes: 1

user936414
user936414

Reputation: 7634

It is not a good idea to start the first activity again on back pressed. Call finish() in the second activity. This will lead to the resume of the first activity which is what you need.

back.setOnClickListener(new OnClickListener() {
    public void onClick(View v) {
        finish();            }
    });
}

Upvotes: 3

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