android基础：广播BroadCast简单案例

运行效果

string.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">TestBroadcast</string>
    <string name="param_input">请输入发送参数</string>
    <string name="send_button">发送广播</string>
    <string name="action_settings">Settings</string>
</resources>

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.mytest.testbroadcast.MainActivity" >

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:hint="@string/param_input"
        android:id="@+id/param_input"/>
    <Button
        android:id="@+id/send_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@id/param_input"
        android:text="@string/send_button"
        android:onClick="SendBroadCast" /> 

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/param_input"
        android:text="@null"
        android:id="@+id/view_result"
       />    

</RelativeLayout>

MainActivity　

package com.mytest.testbroadcast;

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

public class MainActivity extends Activity {

	private EditText paramText;
	private TextView resultView;
	private final String ACTION_INTENT_TEST="com.mytest.testbroad.intent";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		paramText = (EditText) this.findViewById(R.id.param_input);
		resultView = (TextView) this.findViewById(R.id.view_result);
	}

	/**
	 * 发送广播按钮onclick事件
	 * @param view
	 */
	public void SendBroadCast(View view){
		String param = paramText.getText().toString();

		//创建发送intent
		Intent intent = new Intent(this.ACTION_INTENT_TEST);
		//绑定参数
		intent.putExtra("user_input", param);
		//发送广播
		this.sendBroadcast(intent); 

		resultView.setText("发送广播成功，参数值为:"+param);

	}

}

创建广播接听对象

package com.mytest.testbroadcast;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

public class MyBroadCastReceiver extends BroadcastReceiver {

	@Override
	public void onReceive(Context context, Intent intent) {
		// TODO Auto-generated method stub
		String user_input = intent.getStringExtra("user_input");
		Toast.makeText(context,"接收到广播，得到参数值为"+user_input,Toast.LENGTH_SHORT).show();

	}

}

　AndroidMainfest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.mytest.testbroadcast"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="14"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <!-- 注册广播接收类 -->
        <receiver android:name=".MyBroadCastReceiver">
            <intent-filter>
                <action android:name="com.mytest.testbroad.intent"/>
            </intent-filter>

        </receiver>
    </application>

</manifest>

案例实现小结：
1、定义ACTION,并建立发送Intent，调用sendBroadcast方法发送广播；
2、创建广播接收类。类要继承BroadcastReceiver，并重写onReceive方法；
3、在AndroidManifest.xml中注册广播接收对象，在intent-filter中添加ACTION。