android获取上一个activity返回值的方法

 
 

lt;!-- .表示上面 manifest 标签中 package属性的值 -->
              android:name=".DemoActivity"
         android:label="选择联系人" >
    

    xmlns:tools="http://schemas.android.com/tools"
    android:layout_
    android:layout_
    android:orientation="vertical" >

            android:id="@+id/lv"
        android:layout_
        android:layout_ >
   

package com.example.getresultdata;

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

public class MainActivity extends Activity {
    private TextView textView;
    private TextView textView2;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        textView = (TextView) findViewById(R.id.textView);
        textView2 = (TextView) findViewById(R.id.textView2);
    }

    /**
     * 第一个按钮的点击事件
     *
     * @param view
     */
    public void click(View view) {
        Intent intent = new Intent(this, DemoActivity.class);
        // startActivity(intent);
        startActivityForResult(intent, 1);// 请求码
                                            // 用于区分请求的数据,如果只有一个请求(按钮),这个code可以为0,可以不考虑他的值
    }

    /**
     * 第二个按钮的点击事件
     *
     * @param view
     */
    public void click2(View view) {
        Intent intent = new Intent(this, DemoActivity.class);
        // startActivity(intent);
        startActivityForResult(intent, 2);// 请求码
    }

    @Override
    /**
     * 当跳转的activity(被激活的activity)使用完毕,销毁的时候调用该方法
     */
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);
        if (data != null) {
            String name = data.getStringExtra("name");
            if (requestCode == 1) {// 因为有2个按钮,所以要区分是触发了那个按钮的单击事件,然后把返回的数据放到对应的EditText中
                textView.setText(name);
            } else if (requestCode == 2) {
                textView2.setText(name);
            }
        }

    }

}

package com.example.getresultdata;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.content.ContentResolver;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Color;
import android.net.Uri;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class DemoActivity extends Activity {
    private ListView listView;
    private List data;

    @Override  www.jb51.net
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.demo);
        listView = (ListView) findViewById(R.id.lv);// 初始化控件
        data = getAllContacts();// 获取所有的联系人姓名
        listView.setAdapter(new MyAdapter());
        listView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView parent, View view, int position, long id) {
                TextView textView = (TextView) view;
                String name = textView.getText().toString();
                Intent intent = new Intent();
                intent.putExtra("name", name);// 放入返回值
                setResult(0, intent);// 放入回传的值,并添加一个Code,方便区分返回的数据
                finish();// 结束当前的activity,等于点击返回按钮
            }

        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    /**
     * 内部类,为listview添加数据,构成联系人列表
     *
     * @author w
     *
     */
    public class MyAdapter extends BaseAdapter {

        @Override
        public int getCount() {
            // TODO Auto-generated method stub
            return data.size();// 返回listview的总长度
        }

        @Override
        public Object getItem(int position) {
            // TODO Auto-generated method stub
            return position;// 返回当前列表的位置
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return position;// 返回当前列表位置
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            TextView tv = new TextView(DemoActivity.this);
            tv.setTextSize(25);// 设置显示文本的大小,
            tv.setTextColor(Color.RED);// 设置显示文本的颜色
            tv.setText(data.get(position));// 在对应的位置设置联系人数据
            return tv;
        }

    }

    /**
     * 获取所有联系人的姓名
     *
     * @return
     */
    private List getAllContacts() {
        List list = new ArrayList();
        // 或者uri==ContactsContract.Contacts.CONTENT_URI
        Uri uri = Uri.parse("content://com.android.contacts/contacts");
        ContentResolver resolver = this.getContentResolver();
        Cursor cursor = resolver.query(uri, null, null, null, null);
        while (cursor.moveToNext()) {
            String name = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
            list.add(name);
        }
        cursor.close();
        return list;
    }
}