尽管服务活动已放入清单文件中，但发生了此异常

Question

这是我的manifest文件。

<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">
    <service
        android:name=".DelayedMessageService"
        android:exported="false"></service>

    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

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

尽管服务活动已放入清单文件中，但发生了此异常

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.hfad.joke, PID: 11392
    android.content.ActivityNotFoundException: Unable to find explicit activity class {com.hfad.joke/com.hfad.joke.DelayedMessageService}; have you declared this activity in your AndroidManifest.xml?
        at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:2005)
        at android.app.Instrumentation.execStartActivity(Instrumentation.java:1673)
        at android.app.Activity.startActivityForResult(Activity.java:4586)
        at androidx.fragment.app.FragmentActivity.startActivityForResult(FragmentActivity.java:767)
        at android.app.Activity.startActivityForResult(Activity.java:4544)
        at androidx.fragment.app.FragmentActivity.startActivityForResult(FragmentActivity.java:754)
        at android.app.Activity.startActivity(Activity.java:4905)
        at android.app.Activity.startActivity(Activity.java:4873)
        at com.hfad.joke.MainActivity$1.onClick(MainActivity.java:24)
        at android.view.View.performClick(View.java:6597)
        at android.view.View.performClickInternal(View.java:6574)
        at android.view.View.access$3100(View.java:778)
        at android.view.View$PerformClick.run(View.java:25885)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6669)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

此按钮代码转到DelayedMessageService。

Button serviceButton = (Button)findViewById(R.id.button);
        serviceButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(MainActivity.this,DelayedMessageService.class);
                i.putExtra(DelayedMessageService.EXTRA_MESSAGE,getResources().getText(R.string.button_response));
                startActivity(i);
            }
        });

这是服务活动。

public class DelayedMessageService extends IntentService {

    public static final String EXTRA_MESSAGE = "message";

    public DelayedMessageService() {
        super("DelayedMessageService");
    }

    @Override
    protected void onHandleIntent(Intent intent) {
        try{
            synchronized (this){
                wait(10000);
            }
        }catch (InterruptedException ie){
            ie.printStackTrace();
        }
        String text = intent.getStringExtra(EXTRA_MESSAGE);
        showText(text);
    }
    private void showText(final String text) {
        Log.v("DelayedMessageService", "The message is: " + text);
    }
}

Answer 1

在您的按钮中，您将作为活动开始服务。