android学习记录(七)

2021-03-04 19:03:29 阅读：205 来源： 互联网

标签：Toast content 记录学习 Intent import android BroadcastReceiver

动态注册监听时间变化.

MainActivity.kt

package com.example.broadcasttest

import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.content.IntentFilter
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.os.ResultReceiver
import android.widget.Toast

class MainActivity : AppCompatActivity() {
    lateinit var  timeChangeReceiver: TimeChangeReceiver
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val intentFilter=IntentFilter()
        intentFilter.addAction("android.intent.action.TIME_TICK")
        timeChangeReceiver=TimeChangeReceiver()
        registerReceiver(timeChangeReceiver,intentFilter)
    }
    override fun onDestroy() {
        super.onDestroy()
        unregisterReceiver(timeChangeReceiver)
    }
    inner  class TimeChangeReceiver : BroadcastReceiver(){
        override fun onReceive(context: Context?, intent: Intent?) {
            Toast.makeText(context,"Time has changed" ,Toast.LENGTH_SHORT).show()
        }
    }
}

静态注册实现开机启动

BootCompieteReciever.kt

package com.example.broadcasttest

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

class BootCompieteReceiver : BroadcastReceiver() {

    override fun onReceive(context: Context, intent: Intent) {
        // This method is called when the BroadcastReceiver is receiving an Intent broadcast.
        Toast.makeText(context,"Boot Complete",Toast.LENGTH_SHORT).show()
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.broadcasttest">
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.BroadcastTest">
        <receiver
            android:name=".BootCompieteReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED"/>
            </intent-filter>
        </receiver>
        <receiver
            android:name=".MyBroadcastReceiver"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="com.example.broadcasttest.MY_BROADCAST" />
            </intent-filter>
        </receiver>
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

发送标准广播

先写一个接收广播的 MyBroadcastReceiver

package com.example.broadcasttest

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

class MyBroadcastReceiver : BroadcastReceiver() {
    override fun onReceive(context: Context, intent: Intent) {
        // This method is called when the BroadcastReceiver is receiving an Intent broadcast.
        Toast.makeText(context,"received in MyBroadcastReceiver",Toast.LENGTH_SHORT).show()
    }
}

在AndroidManifest.xml中添加相关配置.

  <intent-filter>
                <action android:name="com.example.broadcasttest.MY_BROADCAST" />
            </intent-filter>

用来接收广播.
接着在主界面处添加一个按钮用来触发广播.

<Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/button"
        android:text="Send Broadcast"/>

接着在MainActivity中添加相应的响应来发送广播.

package com.example.broadcasttest

import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.content.IntentFilter
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.os.ResultReceiver
import android.widget.Button
import android.widget.Toast

class MainActivity : AppCompatActivity() {
    lateinit var  timeChangeReceiver: TimeChangeReceiver
    lateinit var  button : Button
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        val intentFilter=IntentFilter()
        intentFilter.addAction("android.intent.action.TIME_TICK")
        timeChangeReceiver=TimeChangeReceiver()
        registerReceiver(timeChangeReceiver,intentFilter)
        button=findViewById(R.id.button)
        button.setOnClickListener {
            val intent =Intent("com.example.broadcasttest.MY_BROADCAST")
            intent.setPackage(packageName)
            sendBroadcast(intent)
        }
    }
    override fun onDestroy() {
        super.onDestroy()
        unregisterReceiver(timeChangeReceiver)
    }
    inner  class TimeChangeReceiver : BroadcastReceiver(){
        override fun onReceive(context: Context?, intent: Intent?) {
            Toast.makeText(context,"Time has changed" ,Toast.LENGTH_SHORT).show()
        }
    }
}

发送有序广播.

另建一个Receiver

AnotherBroadcastReceiver

package com.example.broadcasttest

import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.widget.Toast
class AnotherBroadcastReceiver : BroadcastReceiver() {
    override fun onReceive(context: Context, intent: Intent) {
        // This method is called when the BroadcastReceiver is receiving an Intent broadcast.
        Toast.makeText(context,"recevied in AnotherBroadcastReceiver",Toast.LENGTH_SHORT).show()
    }
}

将广播发送方式换成有序广播.

button.setOnClickListener {
            val intent =Intent("com.example.broadcasttest.MY_BROADCAST")
            intent.setPackage(packageName)
            sendOrderedBroadcast(intent,null)//第二个参数和权限有关.
        }

接着为了显示先后关系可以在AndroidManifest.xml中修改优先级.

<intent-filter android:priority="100">
                <action android:name="com.example.broadcasttest.MY_BROADCAST" />
            </intent-filter>

标签：Toast,content,记录,学习,Intent,import,android,BroadcastReceiver
来源： https://blog.csdn.net/weixin_44110537/article/details/113482201

本站声明： 1. iCode9 技术分享网（下文简称本站）提供的所有内容，仅供技术学习、探讨和分享；
2. 关于本站的所有留言、评论、转载及引用，纯属内容发起人的个人观点，与本站观点和立场无关；
3. 关于本站的所有言论和文字，纯属内容发起人的个人观点，与本站观点和立场无关；
4. 本站文章均是网友提供，不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属；如您发现该文章侵犯了您的权益，可联系我们第一时间进行删除；
5. 本站为非盈利性的个人网站，所有内容不会用来进行牟利，也不会利用任何形式的广告来间接获益，纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。

ICode9