当您点击我的活动中的按钮时,它会启动/显示DatePickerDialog
。当用户选择日期并点击" ok"我想在原始类中运行AsyncTask
(单击按钮的活动)。一切正常但我希望在AsyncTask完成时向用户显示一个TOAST,但是这样做时仍然会出错。
继承我的代码:
BuyerHomePage.java中的Button方法
public void MeetingCreator(){
CalenderImageButton = (ImageButton)findViewById(R.id.CalenderImageButton);
CalenderImageButton.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
DialogFragment picker = new DatePickerFragment();
picker.show(getFragmentManager(), "datePicker");
}
}
);
}
DatePickerFragment.java代码
public class DatePickerFragment extends DialogFragment
implements DatePickerDialog.OnDateSetListener {
public static String formattedDate;
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
// Use the current date as the default date in the picker
final Calendar c = Calendar.getInstance();
int year = c.get(Calendar.YEAR);
int month = c.get(Calendar.MONTH);
int day = c.get(Calendar.DAY_OF_MONTH);
// Create a new instance of DatePickerDialog and return it
return new DatePickerDialog(getActivity(), this, year, month, day);
}
@Override
public void onDateSet(DatePicker view, int year, int month, int day) {
Calendar c = Calendar.getInstance();
c.set(year, month, day);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
formattedDate = sdf.format(c.getTime());
BuyerHomePage Meeting = new BuyerHomePage();
Meeting.new MeetingSender().execute();
}
}
BuyerHomePage.java(AsyncTask中的post方法)
@Override
protected void onPostExecute (String result){
if (result.equals("email sent")) {
//This is where i get the error
Toast.makeText(BuyerHomePage.this, "Email sent!", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(BuyerHomePage.this, "Can't send email", Toast.LENGTH_LONG).show();
}
}
错误日志:
04-23 02:25:31.631 22071-22071/com.wilsapp.wilsapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.wilsapp.wilsapp, PID: 22071
java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
at android.content.ContextWrapper.getResources(ContextWrapper.java:87)
at android.view.ContextThemeWrapper.getResources(ContextThemeWrapper.java:81)
at android.widget.Toast.<init>(Toast.java:102)
at android.widget.Toast.makeText(Toast.java:259)
at com.wilsapp.wilsapp.BuyerHomePage$MeetingSender.onPostExecute(BuyerHomePage.java:930)
at com.wilsapp.wilsapp.BuyerHomePage$MeetingSender.onPostExecute(BuyerHomePage.java:836)
at android.os.AsyncTask.finish(AsyncTask.java:651)
at android.os.AsyncTask.-wrap1(AsyncTask.java)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:668)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
如果有任何混淆或我需要解释任何事情请评论!谢谢!
答案 0 :(得分:0)
试试这个。
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sessionStorage.closedLastTab = '2';
$(window).on('unload beforeunload', function() {
sessionStorage.closedLastTab = '1';
});