Android -- 在一个Activity开启另一个Activity 并 获取他的返回值。

1. 视图示例， 按选择弹出 2界面， 选择选项  回显到1

  

2. 示例代码

MainActivity.java， 第一个activity

public class MainActivity extends Activity {
	private EditText et_number;
	private EditText et_number2;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		et_number = (EditText) findViewById(R.id.et_number);
		et_number2 = (EditText) findViewById(R.id.et_number2);
	}

	/**
	 * 激活一个新的界面 让用户选择联系人
	 * 
	 * @param view
	 */
	public void selectContact(View view) {
		Intent intent = new Intent(this, SelectContactActivity.class);
		// 开启一个新的activity
		// startActivity(intent);
		// 开启一个新的activity 并且获取这个新开启的activity执行完毕后返回的结果
		startActivityForResult(intent, 1);
	}

	/**
	 * 激活一个新的界面 让用户选择第二个联系人
	 * 
	 * @param view
	 */
	public void selectContact2(View view) {
		Intent intent = new Intent(this, SelectContactActivity.class);
		// 开启一个新的activity
		// startActivity(intent);
		// 开启一个新的activity 并且获取这个新开启的activity执行完毕后返回的结果
		startActivityForResult(intent, 2);
	}

	// 当新开启的activity 关闭的时候 调用的方法.
	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		System.out.println("onActivityResult");

		if (data != null) {
			String number = data.getStringExtra("number");
			if (requestCode == 1) {
				et_number.setText(number);
			}else if(requestCode==2){
				et_number2.setText(number);
			}
		}

		super.onActivityResult(requestCode, resultCode, data);
	}

}

SelectContactActivity.java 第二个activity

public class SelectContactActivity extends Activity {
	private ListView lv_select_contact;
	private List contactInfos;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_select_contact);
		lv_select_contact = (ListView) findViewById(R.id.lv_select_contact);
		contactInfos = ContactInfoService.getContactInfos(this);
		lv_select_contact.setAdapter(new ContactAdapter());
		
		//给listview的条目设置 一下点击事件
		lv_select_contact.setOnItemClickListener(new OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView arg0, View arg1, int position,
					long arg3) {
				ContactInfo info = contactInfos.get(position);
				String number = info.getNumber();
				
				//传递数据给调用他的activity
				Intent data = new Intent();
				data.putExtra("number", number);
				setResult(100, data);
				
				//关闭当前的activity 然后传递数据给 调用者 调用者就会执行 onactivityResult的方法
				finish();
			}
		});
		
	}
	
	
	private class ContactAdapter extends BaseAdapter{

		@Override
		public int getCount() {
			return contactInfos.size();
		}

		@Override
		public Object getItem(int position) {
			return null;
		}

		@Override
		public long getItemId(int position) {
			return 0;
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			ContactInfo info = contactInfos.get(position);
			View view = View.inflate(getApplicationContext(), R.layout.contact_item, null);
			TextView tv_name = (TextView) view.findViewById(R.id.tv_contact_name);
			TextView tv_number = (TextView) view.findViewById(R.id.tv_contact_number);
			tv_name.setText(info.getName());
			tv_number.setText(info.getNumber());
			return view;
		}
		
	}
	
}

ContactInfoService.java, 从db获取所有联系人信息

public class ContactInfoService {
	/**
	 * 返回系统所有的联系人的信息
	 * @return
	 */
	public static List getContactInfos(Context context){
		//创建一个系统所有联系人的集合
		List contactInfos = new ArrayList();
		ContentResolver resolver = context.getContentResolver();
		// raw_contact 表的uri
		Uri uri = Uri.parse("content://com.android.contacts/raw_contacts");
		// data 表的uri
		Uri dataUri = Uri.parse("content://com.android.contacts/data");
		Cursor cursor = resolver.query(uri, new String[] { "contact_id" },
				null, null, null);
		while (cursor.moveToNext()) {
			String id = cursor.getString(0);
			if (id != null) {
				Cursor dataCursor = resolver.query(dataUri, new String[] {
						"data1", "mimetype" }, "raw_contact_id=?",
						new String[] { id }, null);
				ContactInfo contactInfo = new ContactInfo();
				while (dataCursor.moveToNext()) {
					String data = dataCursor.getString(0);
					String mimetype = dataCursor.getString(1);
					if("vnd.android.cursor.item/name".equals(mimetype)){
						contactInfo.setName(data);
					}else if("vnd.android.cursor.item/phone_v2".equals(mimetype)){
						contactInfo.setNumber(data);
					}
				}
				contactInfos.add(contactInfo);
				dataCursor.close();
			}
		}
		cursor.close();
		return contactInfos;
	}
}

ContactInfo.java， 联系人javabean

public class ContactInfo {
	private String name;
	private String number;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getNumber() {
		return number;
	}
	public void setNumber(String number) {
		this.number = number;
	}
	
}

activity_main.xml, 第一个activity布局

activity_select_contact.xml， 第二个activity布局

contact_item.xml， ListView布局

AndroidManifest.xml