Android:如何从AsyncTask获取布尔结果?

Question

我想在我的应用程序中检查互联网连接。我找到了一个代码，但我不知道如何使用，因为我真的是一个初学者。

我的代码 ：

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//I want something like this.
if(InternetCheck==true){
Toast("You are connected to internet")
}
else{
Toast("Connection Failed")
}
}
static class InternetCheck extends AsyncTask<Void,Void,Boolean> {
private Consumer mConsumer;
public  interface Consumer { void accept(Boolean internet); }
public  InternetCheck(Consumer consumer) { mConsumer = consumer; execute(); }
@Override protected Boolean doInBackground(Void... voids) { try {
Socket sock = new Socket();
sock.connect(new InetSocketAddress("8.8.8.8", 53), 1500);
sock.close();
return true;
} catch (IOException e) { return false; } }
@Override protected void onPostExecute(Boolean internet) { mConsumer.accept(internet); }
}

但是我不知道如何从AsyncTask获得布尔结果。请教我。

Answer 1

new InternetCheck(new InternetCheck.Consumer() {
@Override
public void accept(Boolean connected) {
if (connected) {
Log.d("TAG", "Internet is connected");
} else {
Log.d("TAG", "Internet is not connected");
}     
}
}).execute();

Answer 2

您可以使用get()从AsyncTask中获取结果：

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Boolean result = new InternetCheck().execute().get();
if (result == true) {
Toast.makeText(this, "You are connected to internet", Toast.LENGTH_LONG).show();
} else { 
Toast.makeText(this, "Connection Failed", Toast.LENGTH_LONG).show();
}
}

或者您可以在onPostExecute()中检查AsyncTask的布尔结果：

@Override 
protected void onPostExecute(Boolean internet) { 
mConsumer.accept(internet);
if (internet == true) {
Toast.makeText(YourActivity.this, "You are connected to internet", Toast.LENGTH_LONG).show();
} else { 
Toast.makeText(YourActivity.this, "Connection Failed", Toast.LENGTH_LONG).show();
}
}