check datagrid.column s value - template

[Mathias123]

Hello!

I have a question.

I have a DataGrid with 3 columns binding (Article Quantity,Blocke d Quantity & a template named Input quantity). i want to check the input QTY value.

for example:
Article QTY = 100
Blocked QTY = 50

I want to input the input QTY, but the maximal value of the input QTY mustn't be over 50 because Article QTY - Blocked QTY is the maximal Value. How can I check that?

 <DataGrid AutoGenerateColumns="False" Grid.RowSpan="2" Grid.ColumnSpan="2" Grid.Row="4" Height="160" HorizontalAlignment="Left" Name="grd_Block_pos" VerticalAlignment="Top" Width="auto">
            <DataGrid.Columns>
                <DataGridTextColumn IsReadOnly="True" Width="auto" Header="Article" Binding="{Binding Article}" />
                <DataGridTextColumn IsReadOnly="True" Width="auto" Header="Product Descr1" Binding="{Binding ProdDescr1}" />
                <DataGridTextColumn IsReadOnly="True" Width="auto" Header="Article QTY" Binding="{Binding Article QTY}" />
                <DataGridTextColumn IsReadOnly="True" Width="auto" Header="Blocked QTY" Binding="{Binding Blocked_QTY}" />
                <DataGridTemplateColumn Header="input_QTY">
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <TextBox Text="{Binding input QTY}" MinWidth="50" Name="input_QTY" BorderThickness="0"/>
                        </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>
            </DataGrid.Columns>
        </DataGrid>
 
 

If I make a LostFocus or TextChanged event on the input_QTY, I get an error:

Private Sub input_QTY_TextChanged(ByVal sender As System.Object, ByVal e As System.Windows.Controls.TextChangedEventArgs) Handles input_QTY.TextChanged
 
    End Sub

Error 13 Handles clause requires a WithEvents variable defined in the containing type or one of its base types.

Can somebody help me?

[Frinavale]

If you want to use the TextChanged event, then keep that method but don't use "Handles". Instead, in your template, specify the function that should be called.

For example:

<DataGridTemplateColumn Header="input_QTY">
  <DataGridTemplateColumn.CellTemplate>
    <DataTemplate>
      <TextBox Text="{Binding input QTY}" TextChanged="input_QTY_TextChanged" MinWidth="50" Name="input_QTY" BorderThickness="0"/>
    </DataTemplate>
  </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

-Frinny

[Mathias123]

hi Frinny!

It works!!!!! Thx for your quick response. I like XAML :)
But the OnTextChanged dont work. In Visual Studio it is TextChanged="in put_QTY_TextCha nged"

thanks a lot!

Nice greets
Mathias

[Frinavale]

Hehe, I'm sorry!

I thought I was answering an asp.net question.
I've modified my response to be correct.

Glad it worked for you.

-Frinny

[Frinavale]

Mathias123, what are you binding to?
If you are binding to a class (like a view model class) you should put your validation in there.

In other words, when the user tries to change the value to something invalid...throw an exception.

You can modify your binding so that it catches exceptions and displays the TextBox with a red outline.

You can go even further and add a tooltip style for the TextBox, so that when there is an error with the data the TextBox is displaying it will be shown as a tool tip if the user hovers over it.

-Frinny

[Mathias123]

yeah thanks for the tip with the red outline... looks great! thx :)