startActivityForResult的用法和demo代码

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,A中处理。

流程如下：

1.A调用B activity，

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

2.B执行操作后将结果返回去：

 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();

3.A得到结果后覆写protected void onActivityResult(int requestCode, int resultCode, Intent data)方法对结果处理。

 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();
     }

 

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

 

 

 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();
             }
         });
     }
 }