根据范围更改DataGrid单元WPF的颜色

Question

Hi I need to implement a function that if the value of the binding items is within the specific range cell color should be according to the range.

I have been using Changing Background Color Of DataGrid Cell WPF 4

this works fine but it is for only if that values are there.what if i want to add range ie from 10 - 20 it is red 21-30 it is blue

added everything and saw an example at the end but the color does not change here is the code

Class

 public class ConvertToBrush : IValueConverter
    {

        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            int tempValue = int.Parse(value.ToString());
            string tempString = "Red";
            if (tempValue >= 0 && tempValue <= 20)
                tempString = "#FF0000";

            if (tempValue > 20 && tempValue <= 40)
                tempString = "#F09300";

            if (tempValue > 40 && tempValue <= 60)
                tempString = "#EDDF00";

            if (tempValue > 60 && tempValue <= 80)
                tempString = "#FFFFFF";

            if (tempValue > 80 && tempValue <= 100)
                tempString = "#85AB00";


            SolidColorBrush brush = new SolidColorBrush();
            BrushConverter conv = new BrushConverter();
            brush = conv.ConvertFromString(tempString) as SolidColorBrush;
            return brush;

        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {

            return DependencyProperty.UnsetValue;
        }
    }

XMAL

  <DataGridTextColumn ElementStyle="{StaticResource CentreAlignStyle}" Binding="{Binding TestResults}" Header="Results" IsReadOnly="True" MaxWidth="60" MinWidth="60" >
                                        <DataGridTextColumn.CellStyle>
                                            <Style>
                                                <Setter Property="TextBlock.Background" Value="{Binding TestResults, Converter={StaticResource makeBrush}}" />
                                            </Style>
                                        </DataGridTextColumn.CellStyle>
                                    </DataGridTextColumn>

Answer 1

Don't use a DataTrigger but just bind the Background to the value and put in a ValueConverter to return the right brush (or no brush at all).

Edit: What the usage should look like:

<DataGridTextColumn.CellStyle>
    <Style>
         <Setter Property="Border.Background" Value="{Binding TestResults, Converter={StaticResource BrushConverter}}" />
    </Style>
</DataGridTextColumn.CellStyle>

Answer 2

I'm not sure i understood you right, but here goes:

So let's say that "TestResults" contains the value you're talking about. In XAML:

<DataGridTextColumn TextBlock.Background={Binding TestResults, Converter={StaticResource makeBrush}} />

Just to make sure we're on the same page here, you define the converter in your XAML like this:

    <Window.Resources>
        <local:makeBrush x:Key="makeBrush" />
    </Window.Resources>

In the makeBrush converter, you do this:

public class makeBrush : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        int theValueToConvertToColor = (int)value;
        if (theValueToConvertToColor > 10 && theValueToConvertToColor <= 20)
        {
            return Brushes.Red;
        }
        if (theValueToConvertToColor > 20 && theValueToConvertToColor <= 30)
        {
            return Brushes.Blue;
        }
        //More ifs...
        else return Brushes.Green;            
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        return value;
    }
}

The " object value " you get in the Convert method of your IValueConverter is actually the value of " TestResults "

Note: I didn't actually test it with a DataGridTextColumn , but i guess you get the point and can make the necessary adjustments if required.