how to send a string from activity2 to activity1?

I have a little/big problem in my app in android.I have 2 activity:Activity1 and Activity2. Activity1 has a TextView and a Button and Activity2 has an EditText and a Button. From Activity1 I go to Acvity2 and 开发者_C百科I want to send the text from EditText from Activity2 to Activity 1. I get force close because I don't know the order in code. What should I do? Thanks

Here is my code :

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

public class Activity1 extends Activity {
    TextView txt;
 public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

       txt = (TextView) findViewById(R.id.txt);

        Button next=(Button)findViewById(R.id.btn);
        next.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                Intent intent = new Intent(Activity1.this,Activity2.class);
                startActivityForResult(intent, 0);
            }

        });
    }

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

public class Activity2 extends Activity {
    EditText txt2;
 public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main2);

        txt2 = (EditText)findViewById(R.id.txt2);
        final Bundle bundle = new Bundle();
        String x=txt2.getText().toString();
        bundle.putString("param",x);
        Button btn2=(Button)findViewById(R.id.btn2);
        btn2.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                Intent intent = new Intent(Activity2.this,Activity1.class);
                intent.putExtra(bundle)
                finish();

            }

        });
          }
}

One problem with your code is that you don't have anything handling the result of the second activity. (There's no onActivityResult in the first activity.)

The notepad tutorial includes a decent example of calling a second activity and getting a result.

In Activity1 @override onActivityResult.

and In Activity2 write this.

txt2 = (EditText)findViewById(R.id.txt2);

final Bundle bundle = new Bundle();
String x=txt2.getText().toString();
Button btn2=(Button)findViewById(R.id.btn2);
btn2.setOnClickListener(new View.OnClickListener() {
    public void onClick(View view) {
        Intent intent = new Intent();
        intent.putExtra("param",x);
        setResult(RESULT_OK, intent);
        finish();
    }

In Activity1 @override onActivityResult.

and In Activity2 write this.

txt2 = (EditText)findViewById(R.id.txt2);
    final Bundle bundle = new Bundle();
    String x=txt2.getText().toString();
    bundle.putString("param",x);
    Button btn2=(Button)findViewById(R.id.btn2);
    btn2.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {
            Intent intent = new Intent();
            intent.putExtra("param",x);
            setResult(RESULT_OK, intent);
            finish();

        }
    });