[转]startActivityForResult的用法和demo

有时候我们需要把A activity提交数据给B  activity处理，然后把结果返回给A

这种方式在很多种情况需要用到，比如我应用的程序需要有拍照上传的功能。

一种解决方案是  我的应用程序 〉调用系统相机〉拍照〉关闭系统相机〉返回拍照后的照片到我的应用程序

启动一个ForResult的意图：

Intent intent = new Intent(MainAcitvity.this,
      RequestActivity.class);
    //发送意图标示为REQUSET=1
    startActivityForResult(intent, REQUSET);

B Activity处理数据：

Intent intent=new Intent();

intent.putExtra(KEY_USER_ID, et01.getText().toString());
    intent.putExtra(KEY_USER_PASSWORD, et02.getText().toString());
setResult(RESULT_OK, intent);
 finish();

那么startActivityForResult如何使用呢：

package com.cn.activityresult.demo;

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.TextView;

import android.widget.Toast;

public class MainAcitvity extends Activity {

    private Button btn01;

    private TextView tv01;

    public static final int REQUSET = 1;

    @Override

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        // TODO Auto-generated method stub

        super.onActivityResult(requestCode, resultCode, data);

        //requestCode标示请求的标示   resultCode表示有数据

        if (requestCode == MainAcitvity.REQUSET && resultCode == RESULT_OK) {

            String str = "账号"

                    + data.getStringExtra(RequestActivity.KEY_USER_ID) + "\n"

                    + "密码"

                    + data.getStringExtra(RequestActivity.KEY_USER_PASSWORD);

            tv01.setText(str);

        }

        Toast.makeText(

                this,

                "requestCode=" + requestCode + ":" + "resultCode=" + resultCode,

                Toast.LENGTH_LONG).show();

    }

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        btn01 = (Button) findViewById(R.id.btn01);

        tv01 = (TextView) findViewById(R.id.tv01);

        btn01.setOnClickListener(new OnClickListener() {

            @Override

            public void onClick(View v) {

                // TODO Auto-generated method stub

                Intent intent = new Intent(MainAcitvity.this,

                        RequestActivity.class);

                //发送意图标示为REQUSET=1

                startActivityForResult(intent, REQUSET);

            }

        });

    }

}  

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 RequestActivity extends Activity {

    private Button btn01;

    private EditText et01;

    private EditText et02;

    public static final String KEY_USER_ID="KEY_USER_ID";

    public static final String KEY_USER_PASSWORD="KEY_USER_PASSWORD";

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.request_activity);

        btn01=(Button)findViewById(R.id.btn01);

        et01=(EditText)findViewById(R.id.et01);

        et02=(EditText)findViewById(R.id.et02);

        btn01.setOnClickListener(new OnClickListener() {

            @Override

            public void onClick(View v) {

                // TODO Auto-generated method stub

                Intent intent=new Intent();

                intent.putExtra(KEY_USER_ID, et01.getText().toString());

                intent.putExtra(KEY_USER_PASSWORD, et02.getText().toString());

                setResult(RESULT_OK, intent);

                finish(); //此处一定要调用finish（）

            }

        });

    }

}