Java Android:初始化意图时找不到类的符号
我正在编写一个简单的Android程序,它使用一个扩展Android的Java Android:初始化意图时找不到类的符号,java,android,broadcastreceiver,Java,Android,Broadcastreceiver,我正在编写一个简单的Android程序,它使用一个扩展Android的BroadcastReceiver的类来初始化Intent。但是,当我运行程序时,我收到以下错误: C:\Users\windows\AndroidStudioProjects\NotificationTest\app\src\main\java\com\example\notificationtest\MainActivity.java:60: error: cannot find symbol Intent
BroadcastReceiver
的类来初始化Intent
。但是,当我运行程序时,我收到以下错误:
C:\Users\windows\AndroidStudioProjects\NotificationTest\app\src\main\java\com\example\notificationtest\MainActivity.java:60: error: cannot find symbol
Intent notificationIntent = new Intent(this, MatchNotification.class);
^
symbol: class MatchNotification
location: class MainActivity
1 error
考虑到我在与MainActivity
相同的文件夹中明确定义了MatchNotification,这似乎有些奇怪。以下是我的main活动
课程:
package com.example.notificationtest;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent notificationIntent = new Intent(this, MatchNotification.class);
}
}
package com.example.notificationtest
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.media.MediaPlayer
import android.media.RingtoneManager
import android.net.Uri
class MatchNotification : BroadcastReceiver() {
private lateinit var player: MediaPlayer;
private lateinit var context: Context;
override fun onReceive(context: Context, intent: Intent) {
this.context = context
// Retrieve the URI of the alarm the user has set
var ringtoneUri:Uri? = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_RINGTONE)
player = MediaPlayer.create(context, ringtoneUri)
player.start()
}
}
下面是我的MatchNotification
课程:
package com.example.notificationtest;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Intent notificationIntent = new Intent(this, MatchNotification.class);
}
}
package com.example.notificationtest
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.media.MediaPlayer
import android.media.RingtoneManager
import android.net.Uri
class MatchNotification : BroadcastReceiver() {
private lateinit var player: MediaPlayer;
private lateinit var context: Context;
override fun onReceive(context: Context, intent: Intent) {
this.context = context
// Retrieve the URI of the alarm the user has set
var ringtoneUri:Uri? = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_RINGTONE)
player = MediaPlayer.create(context, ringtoneUri)
player.start()
}
}
下面是我的AndroidManifest.xml
:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.notificationtest">
<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/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver
android:name=".MatchNotification"
android:enabled="true"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
<action android:name="android.intent.action.QUICKBOOT_POWERON" />
</intent-filter>
</receiver>
</application>
</manifest>
发送一个意图
更像这样:
Intent intent = new Intent();
intent.setAction("com.example.notificationtest.ON_MATCH");
intent.putExtra("data", "Nothing to see here, move along.");
sendBroadcast(intent);
这需要在接收器中添加相应的意图过滤器
:
<receiver
android:name="com.example.notificationtest.MatchNotification"
android:enabled="true"
android:exported="true">
<intent-filter>
...
<action android:name="com.example.notificationtest.ON_MATCH" />
</intent-filter>
</receiver>
...
同时运行:lint
,然后修复它可能抱怨的所有Kotlin互操作性问题。我应该用MatchNotification替换ON_MATCH,对吗?如果这是正确的,我可能会这样写;只需将intent过滤器
添加到接收器
。意图操作与映射的类名完全无关;你可以叫它任何你喜欢的名字,除了已经采取行动的名字。我的意思是,如果仅限于类名,那么每个意图过滤器都需要一个额外的接收器
,这是没有意义的。