Android 如何在AsyncTask';结束?
我有一个Android 如何在AsyncTask';结束?,android,android-asynctask,android-progressbar,Android,Android Asynctask,Android Progressbar,我有一个AsyncTask查询数据库,然后返回boolean 我试图在onPostExecute方法上关闭progressbars可见性。我要走了 nullpointerexception: Attempt to invoke virtual method 'void android.widget.ProgressBar.setVisibility(int)' on a null object reference 因为我不能正确地引用它 我该怎么做 异步任务: public class Tar
AsyncTask
查询数据库,然后返回boolean
我试图在onPostExecute
方法上关闭progressbars可见性。我要走了
nullpointerexception: Attempt to invoke virtual method 'void android.widget.ProgressBar.setVisibility(int)' on a null object reference
因为我不能正确地引用它
我该怎么做
异步任务:
public class TarefaValidaEmail extends AsyncTask<String, Void, Boolean> {
private Context context;
private Cadastro cadastro = new Cadastro();
public TarefaValidaEmail(Context context){
this.context = context;
}
@Override
protected Boolean doInBackground(String... params) {
String email = params[0];
Log.d("STRING BACKGROUND: ", email);
UsuarioDAO dao = new UsuarioDAO();
boolean isEmailValido = dao.isEmailValido(email);
return isEmailValido;
}
@Override
protected void onPostExecute(Boolean isEmailValido){
cadastro.isEmailValido(isEmailValido);
cadastro.progress.setVisibility(View.INVISIBLE);
}
}
已在Cadastro活动和Tarefa AsyncTask类上尝试了
Cadastro.this.progress.setVisib..
。谢谢 关闭onpostexecute()方法中的进度条
在这里:
导致问题的线路
因为您正在将Cadastro.this
发送到TarefaValidaEmail
类,所以访问进度
为:
public TarefaValidaEmail(Context context){
this.context = context;
this.cadastro=((Cadastro)context);
}
progress.dismiss();
private Cadastro cadastro = new Cadastro();
public TarefaValidaEmail(Context context){
this.context = context;
this.cadastro=((Cadastro)context);
}