我正在开发我的第一个Android应用程序,希望在用户单击登录按钮时显示进度对话框。因此,我将asynctask集成到应用程序中,所有操作如登录注销都已成功完成,但问题是成功登录后会出现错误,例如LoginActivity由于进度对话框而泄漏窗口。如何关闭进度对话框并更新UI。
请参考以下代码并告诉我需要做哪些更改:
以下是 LoginActivity:
public class LoginActivity extends SherlockActivity {
.................
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
sessionmngr = new SessionManager(this);
//check the user login or not
if (sessionmngr.isLoggedIn()) {
Intent checkLoginIntnt = new Intent(this,ProjectFragActivity.class);
startActivity(checkLoginIntnt);
}
setContentView(R.layout.activity_login);
........
}
// onclick listener when click on login activity
public void LoginToBookingScape(View v) throws JSONException {
username = edtTxtUserName.getText().toString();
userpsw = edtTxtUserPsw.getText().toString();
if ((username.trim().length() > 0)&&(userpsw.trim().length() > 0)) {
JsonWebService jsonWebs = new JsonWebService();
jsonWebs.execute(loginUrl);
}else {
............
}
}
以下是LoginActivity中扩展AsyncTask的内部类。
private class JsonWebService extends AsyncTask<String,Void,String> {
private ProgressDialog dialogLogin;
@Override
protected String doInBackground(String... url) {
httpPost.setEntity(new UrlEncodedFormEntity(params));
....
inStream = httpEntity.getContent();
.........
return jsonResp;
}
@Override
protected void onPostExecute(String jsonData) {
//get string data from doinBackground
try {
JSONObject jsonObj = new JSONObject(jsonData);
String key_login = jsonObj.getString(KEY_LOGIN);
if (key_login.equalsIgnoreCase("0")) {
.............
}else {
....
sessionmngr = new SessionManager(getApplicationContext());
sessionmngr.createLoginSession(id,jsonObj.getString(KEY_UNAME),
jsonObj.getString(KEY_UEMAIL));
dialogLogin = ProgressDialog.show(LoginActivity.this, "Bookingscape",
"Please Wait",true);
dialogLogin.setIcon(R.drawable.icon);
new Thread(new Runnable() {
@Override
public void run() {
try {
Thread.sleep(4000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}).start();
Intent inteProj = new Intent(getApplicationContext(),
ProjectFragActivity.class);
startActivity(inteProj);
finish();
}
........
}
@Override
protected void onCancelled() {
dialogLogin.dismiss();
dialogLogin = null;
super.onCancelled();
}
}
我希望在这里问一个问题:
以上代码是否优化并且可重用?
提前致谢!