我正在学习如何在Android中处理和使用函数式编程。因此,我开发了以下代码。我想将HandlerThread视为可观察到的,但是当我尝试从以下位置调用.start()时 .map()运算符,我收到以下错误:
no instances of type variable(s) R exists so that void conforms to R
请让我知道为什么出现此错误以及如何解决它。
代码:
public Single<HandlerThread> getObsInitializedHandlerThread() {
this.mMyHandlerThread = new MyHandlerThread(NAME_MY_HANDLER_THREAD);
return Single.just(this.mMyHandlerThread);
}
@Override
protected void onResume() {
super.onResume();
String TAG_LOG = ActMain.TAG_LOG + "." + "onResume()";
Log.v(TAG_LOG, ":");
this.getObsInitializedHandlerThread()
.map(mMyHandlerThread -> mMyHandlerThread.start());
}
private class MyHandlerThread extends HandlerThread {
public MyHandlerThread(String name) {
super(name);
String TAG_LOG = ActMain.class.getSimpleName() + "." + "MyHandlerThread() Constructor";
Log.v(TAG_LOG, ":");
}
@Override
protected void onLooperPrepared() {
super.onLooperPrepared();
String TAG_LOG = ActMain.class.getSimpleName() + "." + onLoopPrepared()";
Log.v(TAG_LOG, ":");
}
}
答案 0 :(得分:0)
在地图中,您始终需要返回一个值(T),不能返回空值,所以您可以尝试
body = body.replace(/(?:href=(?:"|'))((?:(?:(?:\/)))?(?:(?:\.\.\/)*)?(?:(?:[a-zA-Z0-9-_]+\/?)+)?(?:(?:[a-zA-Z0-9-_])*(\.[a-zA-Z0-9-_]{1,})+)?)(?:"|')/g, (a, b) => {
return `href="${config.get('baseUrl')}api/preview?url=${new URL(b, target).href}"`;
});*/