如何从 AsyncTask 返回布尔值? [英] How do I return a boolean from AsyncTask?
问题描述
我有一些编辑文本,用户可以输入 ftp 地址、用户名、密码、端口和 testConnection 按钮.如果连接成功建立,则返回布尔值 true.
I have some EditTexts that a user enters an ftp address, username, password, port anda testConnection button. If a connection is successfully estabished it returns a boolean value of true.
boolean status = ftpConnect(_address, _username, _password,_port);
ftpDisconnect();
if (status == true) {
Toast.makeText(SiteManager.this, "Connection Succesful",
Toast.LENGTH_LONG).show();
} else {
Toast.makeText(SiteManager.this,
"Connection Failed:" + status, Toast.LENGTH_LONG).show();
}
我正在修改我的代码以使用 AsyncTasks 来执行各种 ftp 操作,但是如果成功建立连接,我如何传回一个布尔值?
I'm reworking my code to use AsyncTasks to perform the various ftp operations, but how can I pass back a boolean value if a connection is successfully made?
testConnection.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
_name = etSitename.getText().toString();
_address = etAddress.getText().toString();
_username = etUsername.getText().toString();
_password = etPassword.getText().toString();
_port = Integer.parseInt(etPort.getText().toString());
AsyncConnectTask task = new AsyncConnectTask(SiteManager.this,
_address, _username, _password, _port);
task.execute();
// boolean status = ftpConnect(_address, _username, _password,
// _port);
// ftpDisconnect();
// if (status == true) {
// Toast.makeText(SiteManager.this, "Connection Succesful",
// Toast.LENGTH_LONG).show();
// savesite.setVisibility(0);
// } else {
// Toast.makeText(SiteManager.this,
// "Connection Failed:" + status, Toast.LENGTH_LONG)
// .show();
// }
}
});
还有我的 AsyncTask
And my AsyncTask
public class AsyncConnectTask extends AsyncTask<Void, Void, Void> {
private Context mContext;
private FTPHelper ftpHelper = new FTPHelper();
private String _address;
private String _user;
private String _pass;
private int _port;
ProgressDialog progressDialog;
public AsyncConnectTask(Context context, String address, String user,
String pass, int port) {
mContext = context;
_address = address;
_user = user;
_pass = pass;
_port = port;
}
// declare other objects as per your need
@Override
protected void onPreExecute() {
progressDialog = ProgressDialog.show(mContext, "Please wait for ",
"Process Description Text", true);
// do initialization of required objects objects here
};
@Override
protected Void doInBackground(Void... params) {
boolean status = ftpHelper.ftpConnect(_address, _user, _pass, _port);
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
progressDialog.dismiss();
};
}
推荐答案
public interface MyInterface {
public void myMethod(boolean result);
}
public class AsyncConnectTask extends AsyncTask<Void, Void, Boolean> {
private MyInterface mListener;
public AsyncConnectTask(Context context, String address, String user,
String pass, int port, MyInterface mListener) {
mContext = context;
_address = address;
_user = user;
_pass = pass;
_port = port;
this.mListener = mListener;
}
@Override
protected Boolean doInBackground(Void... params) {
....
return result;
}
@Override
protected void onPostExecute(Boolean result) {
if (mListener != null)
mListener.myMethod(result);
}
}
AsyncConnectTask task = new AsyncConnectTask(SiteManager.this,
_address, _username, _password, _port, new MyInterface() {
@Override
public void myMethod(boolean result) {
if (result == true) {
Toast.makeText(SiteManager.this, "Connection Succesful",
Toast.LENGTH_LONG).show();
} else {
Toast.makeText(SiteManager.this, "Connection Failed:" + status, Toast.LENGTH_LONG).show();
}
}
});
task.execute();
如果您从 onPostExecute
调用 myMethod
,其中的代码将在 UI 线程上运行.否则你需要通过 Handler
If you call myMethod
from onPostExecute
the code inside it will run on the UI Thread. Otherwise you need to post a Runnable through a Handler
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