How To Dynamically Disable Cells in the Grid?

[Steve]

I have a grid that represents six months of data, where each cell represents a day.  The grid has 6 rows and 33 columns (Month, Days 1 through 31, Total).  How would I dynamically disable those cells that do not represent a valid date (e.g. Feb 30, Feb 31, Apr 31, etc.) so that the user cannot enter data in them?  The grid will either show the first half of a year, or the second half of a year (Jan - Jun, or Jul - Dec).

[Maya]

Hi Steve Dentel,

A possible approach may be to use the IsReadOnlyBinding that can be set to True for those cells you do not want to edit. You may take a look at our online documentation for a reference.
 

All the best,
Maya
the Telerik team

[Steve]

I looked at the example (XAML).  How would I do this in the code behind?  What about the fact that I am trying to disable different cells (days), depending on the row (month).  Take a look at the screen shot showing my grid.  Each hand drawn red 'X' represents a date that I don't want to allow the user to edit.

[Maya]

Hello Steve Dentel,

You may define the IsReadOnlyBinding in the code-behind like follows:

GridViewDataColumn column = new GridViewDataColumn();
column.DataMemberBinding = new Binding("Name");
column.IsReadOnlyBinding = new Binding("IsActive");
this.clubsGrid.Columns.Add(column);

In this case IsActive is a property of the business object. You may take a look at this forum thread for a reference and a sample project demonstrating how you may use the IsReadOnlyBinding.
Another possible approach may be to use a CellStyleSelector and color those cells which do not have any values for example. You may take a look at our online documentation and demos for further information.

All the best,
Maya
the Telerik team

[Steve]

Hello Maya,

Can you make the TelerikSL2010Q2 solution available that was shown in the RadGridView - Style and Template Selectors video for Silverlight and WPF?

Thanks,

Steve

[Maya]

Hi Steve Dentel,

May you provide a bit more details which video are you referring to ? Do you require a sample demonstrating the usage of Style and Template Selectors ?
 

All the best,
Maya
the Telerik team

[Steve]

Hi Maya,

It is the video on this page:  http://www.telerik.com/help/silverlight/gridview-cell-style-selector.html

Thanks,

Steve

[Maya]

Hi Steve Dentel,

You may find a sample project attached.

All the best,
Maya
the Telerik team

[Steve]

Hi Maya,

That is not the solution displayed in the video...see attached screen shot.  A suggestion:  when training videos are published on your website that utilize a specific VS solution, please also publish the solutions shown in the video.

Thank you.

Steve

[Steve]

Hi Maya,

Would you please provide the solution referenced in the video?

Thanks,

Steve

[Maya]

Hello Steve Dentel,

I am sending you the sample project used in the video.
I hope that helps.
 

Kind regards,
Maya
the Telerik team

[Tyree]

If you set the IsReadOnlyBinding={Binding DateString,Converter={StaticResource IsInvalidDate}}
Where your DateString is not actually as obviously it would error, then in the converter you test if its a valid date...if not return true. Of course thats assuming your doing some sort of MVVM or add the property to your row item. If your trying to build a grid via the code behind you can do something more direct like {Binding Month /* 2/1/2011 */, Converter={StaticResource IsDateNotInMonth}, ConverterParamenter=29 /* day number */} checking if the parameter is valid for the month in question.

[Steve]

Thank you for providing the solution shown in the video.  After some trial and error, I am using the conditional style converter with three numeric converters.  Below is the xaml for the UserControl.Resources section

<UserControl.Resources>
    <Style x:Key="Day29StyleIsValid"
           TargetType="rgv:GridViewCell">
        <Setter Property="IsEnabled" Value="True" />
    </Style>
    <Style x:Key="Day29StyleIsNotValid"
           TargetType="rgv:GridViewCell">
        <Setter Property="IsEnabled" Value="False" />
    </Style>
    <local:Day29Converter x:Key="zDay29Converter" />
    <local:ConditionalStyleSelector x:Key="Day29StyleSelector"
                ConditionConverter="{StaticResource zDay29Converter}">
        <local:ConditionalStyleSelector.Rules>
            <local:ConditionalStyleRule Style="{StaticResource Day29StyleIsValid}">
                <local:ConditionalStyleRule.Value>
                    <sys:Boolean>True</sys:Boolean>
                </local:ConditionalStyleRule.Value>
            </local:ConditionalStyleRule>
            <local:ConditionalStyleRule Style="{StaticResource Day29StyleIsNotValid}">
                <local:ConditionalStyleRule.Value>
                    <sys:Boolean>False</sys:Boolean>
                </local:ConditionalStyleRule.Value>
            </local:ConditionalStyleRule>
        </local:ConditionalStyleSelector.Rules>
    </local:ConditionalStyleSelector>
    <Style x:Key="Day30StyleIsValid"
           TargetType="rgv:GridViewCell">
        <Setter Property="IsEnabled" Value="True" />
    </Style>
    <Style x:Key="Day30StyleIsNotValid"
           TargetType="rgv:GridViewCell">
        <Setter Property="IsEnabled" Value="False" />
    </Style>
    <local:Day30Converter x:Key="zDay30Converter" />
    <local:ConditionalStyleSelector x:Key="Day30StyleSelector"
                ConditionConverter="{StaticResource zDay30Converter}">
        <local:ConditionalStyleSelector.Rules>
            <local:ConditionalStyleRule Style="{StaticResource Day30StyleIsValid}">
                <local:ConditionalStyleRule.Value>
                    <sys:Boolean>True</sys:Boolean>
                </local:ConditionalStyleRule.Value>
            </local:ConditionalStyleRule>
            <local:ConditionalStyleRule Style="{StaticResource Day30StyleIsNotValid}">
                <local:ConditionalStyleRule.Value>
                    <sys:Boolean>False</sys:Boolean>
                </local:ConditionalStyleRule.Value>
            </local:ConditionalStyleRule>
        </local:ConditionalStyleSelector.Rules>
    </local:ConditionalStyleSelector>
    <Style x:Key="Day31StyleIsValid"
           TargetType="rgv:GridViewCell">
        <Setter Property="IsEnabled" Value="True" />
    </Style>
    <Style x:Key="Day31StyleIsNotValid"
           TargetType="rgv:GridViewCell">
        <Setter Property="IsEnabled" Value="False" />
    </Style>
    <local:Day31Converter x:Key="zDay31Converter" />
    <local:ConditionalStyleSelector x:Key="Day31StyleSelector"
                ConditionConverter="{StaticResource zDay31Converter}">
        <local:ConditionalStyleSelector.Rules>
            <local:ConditionalStyleRule Style="{StaticResource Day31StyleIsValid}">
                <local:ConditionalStyleRule.Value>
                    <sys:Boolean>True</sys:Boolean>
                </local:ConditionalStyleRule.Value>
            </local:ConditionalStyleRule>
            <local:ConditionalStyleRule Style="{StaticResource Day31StyleIsNotValid}">
                <local:ConditionalStyleRule.Value>
                    <sys:Boolean>False</sys:Boolean>
                </local:ConditionalStyleRule.Value>
            </local:ConditionalStyleRule>
        </local:ConditionalStyleSelector.Rules>
    </local:ConditionalStyleSelector>
</UserControl.Resources>

Here's the xaml on the grid for the three days that I want to check:

<telerik:GridViewDataColumn x:Name="Day29Col"
    DataMemberBinding="{Binding Path=Day29, Mode=TwoWay}"
    Header="29" IsFilterable="False" IsSortable="False"
    CellStyleSelector="{StaticResource Day29StyleSelector }" />

<telerik:GridViewDataColumn x:Name="Day30Col"
    DataMemberBinding="{Binding Path=Day30, Mode=TwoWay}"
    Header="30" IsFilterable="False" IsSortable="False"
    CellStyleSelector="{StaticResource Day30StyleSelector }" />

<telerik:GridViewDataColumn x:Name="Day31Col"
    DataMemberBinding="{Binding Path=Day31, Mode=TwoWay}"
    Header="31" IsFilterable="False" IsSortable="False"
    CellStyleSelector="{StaticResource Day31StyleSelector }" />

And here is the first converter...the others are similar.  In the code below, ExerciseDate is always set to the first day of the month...e.g. 2/1/2011

public class Day29Converter : IValueConverter
{
    public object Convert(object value,
        Type targetType,
        object parameter,
        System.Globalization.CultureInfo culture)
    {
        ParticipantExerciseDetail ped = value as ParticipantExerciseDetail;
        if (ped != null)
        {
            // Add 28 days to the ExerciseDate, which is always day 1.
            // If the 29th is a valid date, then the month
            // component of day will not have changed.
            DateTime day = new DateTime();
            day = ped.ExerciseDate.AddDays(28);
            return day.Month == ped.ExerciseDate.Month ? true : false;
        }
        return null;
    }
    public object ConvertBack(object value,
        Type targetType,
        object parameter,
        System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

[Jerry T.]

How would one setup a CellStyleSelector using the MVVM method?

I was looking at the attached project from the Posted on Jan 20, 2011 post and it looks like the general idea I need to use but we're using MVVM so I don't have direct access from the codebehind.

Or, is there some way to access the grid's data thru the grid's properties/methods?