《Android应用开发详解》- Chapter05_Activity_TransData – Activity之间传递数据

在WEB开发中，我们常把数据放在某个Scope中（如request、session）来实现数据的共享，在Android系统中不同的Activity之间是如何传递数据的呢？这里要用到另一个对象Bundle，我们将要传递的信息封装到该对象里面，并通过Intent对象传递到另一个Intent中。

1. 布局文件main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" android:layout_width="fill_parent"
	android:layout_height="fill_parent">

	<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
		android:orientation="horizontal" android:layout_width="fill_parent"
		android:layout_height="wrap_content">
		
		<TextView 
		android:text="请输入用户名称：" 
		android:id="@+id/TextView01"
		android:layout_width="wrap_content" 
		android:layout_height="wrap_content"></TextView>
			
		<EditText 
		android:text="" 
		android:id="@+id/EditText01"
		android:layout_width="fill_parent" 
		android:layout_height="wrap_content"></EditText>
	</LinearLayout>
	
	<Button 
	android:text="查询" 
	android:id="@+id/Button01"
	android:layout_width="wrap_content" 
	android:layout_height="wrap_content"
	android:layout_gravity="right"></Button>
		
</LinearLayout>

2. 布局文件result.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    
    <TextView 
    android:text="" 
    android:id="@+id/TextView02" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content"></TextView>

</LinearLayout>

3. MainActivity.java

package com.amaker.test;

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 MainActivity extends Activity {
	private Button b1;
	private EditText myEditText;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
         b1 = (Button)findViewById(R.id.Button01);
         
         myEditText = (EditText)findViewById(R.id.EditText01);
         b1.setOnClickListener(new OnClickListener() {
			public void onClick(View v) {
				 String name = myEditText.getText().toString();
		         Bundle data = new Bundle();
		         data.putString("name", name);
		         
		         Intent intent = new Intent(MainActivity.this,ResultActivity.class);
		         intent.putExtras(data);
		         startActivity(intent);
			}
		});
         
    }
}

4. ResultActivity.java

package com.amaker.test;

import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.provider.ContactsContract.Contacts;
import android.widget.TextView;

public class ResultActivity extends Activity {
	private TextView tv;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		
		
		setContentView(R.layout.result);
        tv = (TextView)findViewById(R.id.TextView02);
		
		Intent intent = getIntent();
		Bundle b = intent.getExtras();
		String name = b.getString("name");

		String[] projection = new String[] { Contacts._ID,
				Contacts.DISPLAY_NAME};

		Uri contacts = Contacts.CONTENT_URI;
		String[] args = {name};
		
		Cursor managedCursor = managedQuery(contacts, projection, 																		
				"display_name=?", 
				args, 
				Contacts.DISPLAY_NAME + " ASC");
		
		
		if(managedCursor.moveToFirst()){
			Uri contacts_phone = ContactsContract.CommonDataKinds.Phone.CONTENT_URI;			
			String[] phone  = new String[] { ContactsContract.CommonDataKinds.Phone.CONTACT_ID,
					ContactsContract.CommonDataKinds.Phone.NUMBER};
			
			String ID = managedCursor.getString(0);
			String[] args1 = {ID};		
			Cursor managedCursor_phone = managedQuery(contacts_phone, phone, 																		
					"contact_id=?", 
					args1, 
					null);
			
			String number = ""; 			
			if(managedCursor_phone.moveToFirst()){
				number = managedCursor_phone.getString(1);				
			}
			
			String name1 = managedCursor.getString(1);
			tv.setText(name1+":"+number);
		}

	}
}

注：我对原书程序略作了修改，因为提取联系人号码现在的版本不能直接用Peopple.NUMBER了，要先获取到联系人ID，再用ID查ContactsContract.CommonDataKinds.Phone.NUMBER来获取。

5. 运行结果

Chapter05_Activity_TransData实例源码：