WPF DatePicker UpdateSourceTrigger PropertyChanged not working

updatesourcetriggerwpf

I am using MVVM and want to enable a button on text change of datepicker control..

XAML Code:
Binding on DatePicker

SelectedDate="{Binding InactiveDate, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
DisplayDate="{Binding InactiveDate, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}">

Binding on Button:

<Button Margin="10" Command="{Binding SubmitCommand}"

View Model Code:
I am using a DelegateCommand for button click

View Model Delegate Initialization

SubmitCommand = new DelegateCommand(OnSubmitRequested, AllowSubmit, Controller);

The AllowSubmit implementation

private bool AllowSubmit()
{
    return InactiveDate != null;
}

InactiveDate Property implementation

    public DateTime? InactiveDate
    {
        get
        {
            return _inactiveDate;
        }

        set
        {
            _inactiveDate = value;
            SubmitCommand.RaiseCanExecuteChanged();
            PropertyChanged(this, new PropertyChangedEventArgs("InactiveDate"));
        }
    }

SubmitCommand.RaiseCanExecuteChanged() should enable the button once I enter any character on DateTimePicker but it is not happening.

Best Answer

Selected Date property does not work properly. I might be a bit late now, but you can use CurrentDateTimeText property of RadDatePicker

Related Solutions

C# – WPF Datepicker returns previously selected Date using MVVM

I'm not sure what you are trying to achieve by binding the change to the event and command. Is there a reason why you don't bind the SelectedDate Property of your DatePicker (using TwoWay mode)? Currently you're binding it to a static DateTime.Today.

<DatePicker x:Name="dpEventDate" Grid.Row="1" Grid.Column="2" HorizontalAlignment="Stretch" Margin="150,0,150,0" 
      VerticalAlignment="Center" SelectedDateFormat="Long" 
      SelectedDate="{Binding MyDateTimeProperty, Mode=TwoWay}">

and in your ViewModel having a

private Nullable<DateTime> myDateTimeProperty = null;
public Nullable<DateTime> MyDateTimeProperty {
    get {
        if(myDateTimeProperty == null) {
            myDateTimeProperty = DateTime.Today;
        }
        return myDateTimeProperty;
    }
    set {
        myDateTimeProperty = value;
        RaisePropertyChangedEvent("MyDateTimeProperty");
    }
}

This way your ViewModel will return the current date and set it in the DatePicker, if the date is null previously and if the DatePicker is changed, it will bind it's new way back to the property.

Gnuplot: using custom point shapes, with legend entry

This won't be an answer because I'm going to tell you to change your terminal ... I know...

There is no way to add user-defined point shape in gnuplot yet, but the PostScript terminal allows about 70 different : Postscript point types http://www.cp.cmc.osaka-u.ac.jp/~fumiko/tips/gnuplot_pt.jpg

In the following discussion, they state that there's no general mechanism to add user defined point type. And they come with the solution you gave in your question. https://groups.google.com/forum/?fromgroups=#!topic/comp.graphics.apps.gnuplot/in57UNxG2o0

I think a way to achieve your objective may be to

Use postscript to process a "human-readable" .ps file, using default point types.
"post-process" (=parse) the .ps file (it sounds like Inception to me) to change the old fashion ugly default point type into something you like, from unicode chars to home drawn shapes.
ps2pdf or ps2somethingyoulike the processed .ps file.

I'm afraid I will have to face the same problem, so let the world know if you find an easier solution :)

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