webservice method repeats itself more than once when clicking on button - web-services

Question

i have created an android app via xamarin.android. i have a recyclerview that gets its data from an asmx webservice. the recyclerview is filled correctly. i also have a floatingActionButton that deletes rows from the recyclerview, and floatingActionButton save that saves the data that is in the recyclerview in a database table in sqlserver. this is the code:
private void Presave_Click(object sender, EventArgs e)
{
if (laborers_dt_total.Rows.Count == 0)
{
Toast.MakeText(this.Context, "select the laborers that you need!", ToastLength.Long).Show();
}
else
{
ws.get_labors_of_todayAsync(0, "", 3);
ws.get_labors_of_todayCompleted += Ws_get_labors_of_todayCompleted;
supp_status = 1;
}
}
private void Ws_get_labors_of_todayCompleted(object sender, WSattendane1.get_labors_of_todayCompletedEventArgs e)
{
AlertDialog.Builder alert = new AlertDialog.Builder(this.Context);
List<String> repeated_laborers = new List<String>();
DataTable labors_today = new DataTable();
labors_today = e.Result;
try
{
for(int i=0;i<laborers_dt_total.Rows.Count;i++)
{
for (int j = 0; j < labors_today.Rows.Count; j++)
{
if(laborers_dt_total.Rows[i]["laborerCode"].ToString() == labors_today.Rows[j]["laborerCode"].ToString())
{
repeated_laborers.Add(laborers_dt_total.Rows[i]["laborerName"].ToString());
}
}
}
string message = "";
if (repeated_laborers.Count > 0)
{
for (int i = 0; i < repeated_laborers.Count; i++)
{
message = message + repeated_laborers[i] + ", ";
}
alert.SetTitle(Resources.GetText(Resource.String.repeated_names));
alert.SetMessage(message + Resources.GetText(Resource.String.exits_else_where));
alert.SetPositiveButton(Resources.GetText(Resource.String.ok), (senderAlert, args) =>
{
_dialog.Dismiss();
});
_dialog = alert.Create();
_dialog.Show();
}
else if (repeated_laborers.Count==0)
{
Toast.MakeText(context, "uuydsa", ToastLength.Short).Show();
ws.presave_scheduleAsync(laborers_dt_total, user.sch_code, DateTime.Now.Hour.ToString(), project_code, int.Parse(phase_order), "SCH", "SCH", "", userid, int.Parse(department_code), int.Parse(department_code), 0, supp_status, user.create_update);
ws.presave_scheduleCompleted += Ws_presave_scheduleCompleted;
presave.ClearFocus();
}
}
catch (System.Reflection.TargetInvocationException exp)
{
System.Net.WebException exception = new System.Net.WebException("can't reach server", exp.InnerException);
Toast.MakeText(this.Context, exp.InnerException.Message, ToastLength.Long).Show();
Context context = this.Context;
alert.SetTitle("Connection failed");
alert.SetMessage("Please, Check your Internet Connection!");
alert.SetPositiveButton("Retry", (senderAlert, args) =>
{
ws.get_labors_of_todayAsync(0, "", 3);
ws.get_labors_of_todayCompleted += Ws_get_labors_of_todayCompleted;
alert.Dispose();
});
_dialog = alert.Create();
_dialog.Show();
}
}
the problem is that on each click on presave, the function ws.get_labors_of_todayCompleted += Ws_get_labors_of_todayCompleted; repeats itself "number of presave clicks" times. i removed all the code inside it and added just a toast. on each click, the toast is displayed "number of presave clicks" times. i click it for the first time, the toast appears once, then i click it again, the toast repeats itself twice, and so on. what is the problem? thanks in advance.

Answer 1

private void Presave_Click(object sender, EventArgs e)
{
if (laborers_dt_total.Rows.Count == 0)
{
Toast.MakeText(this.Context, "select the laborers that you need!", ToastLength.Long).Show();
}
else
{
ws.get_labors_of_todayAsync(0, "", 3);
ws.get_labors_of_todayCompleted += Ws_get_labors_of_todayCompleted;
supp_status = 1;
}
}
From your code ,we can find there is an if statement,if the first condition laborers_dt_total.Rows.Count == 0 does not satisfy the condition,then it will go to execute the following code:
{
ws.get_labors_of_todayAsync(0, "", 3);
ws.get_labors_of_todayCompleted += Ws_get_labors_of_todayCompleted;
supp_status = 1;
}
So, if the condition laborers_dt_total.Rows.Count == 0 is not always satisfied, it is nomal on each click on presave, the function ws.get_labors_of_todayCompleted += Ws_get_labors_of_todayCompleted; repeats itself "number of presave clicks" times.
In summary, you can recheck the value of laborers_dt_total.Rows.Count .
In addition, if you don't want to execute event Presave_Clickafter your first clicking this button, you can use Xamarin.Forms ActivityIndicator to achieve this. which displays an animation to show that the application is engaged in a lengthy activity.

Answer 2

I would just change:
{
ws.get_labors_of_todayAsync(0, "", 3);
ws.get_labors_of_todayCompleted += Ws_get_labors_of_todayCompleted;
supp_status = 1;
}
to:
{
ws.get_labors_of_todayAsync(0, "", 3);
ws.get_labors_of_todayCompleted -= Ws_get_labors_of_todayCompleted;
ws.get_labors_of_todayCompleted += Ws_get_labors_of_todayCompleted;
supp_status = 1;
}
This will ensure your don't keep accumulating method calls.