how to change combo box background color in WPF?

Question

I have a WPF project, I want to set its background color dynamically, this is my XAML code

<Window.Resources>
        <SolidColorBrush x:Key="TextBoxBorderColor" Color="#FFB4A5B4"/>
        <SolidColorBrush x:Key="TextBoxForegroundColor" Color="Black"/>
        <SolidColorBrush x:Key="TextBoxBackgroundColor" Color="White"/>
</Window.Resources>
<ComboBox x:Name="cmbUserFullName" Background="{DynamicResource TextBoxBackgroundColor}" Foreground="{DynamicResource TextBoxForegroundColor}" 
                          BorderBrush="{DynamicResource TextBoxBorderColor}">
</ComboBox>

And this is my code behind


 var brush7 = FindResource("TextBoxBackgroundColor") as SolidColorBrush;
            if (!string.IsNullOrEmpty(Default.clrPckerTextBoxBackground)) brush7.Color = (Color)ColorConverter.ConvertFromString(Default.clrPckerTextBoxBackground);

            var brush8 = FindResource("TextBoxForegroundColor") as SolidColorBrush;
            if (!string.IsNullOrEmpty(Default.clrPckerTextBoxForeground)) brush8.Color = (Color)ColorConverter.ConvertFromString(Default.clrPckerTextBoxForeground);

            var brush9 = FindResource("TextBoxBorderColor") as SolidColorBrush;
            if (!string.IsNullOrEmpty(Default.clrPckerTextBoxBorder)) brush9.Color = (Color)ColorConverter.ConvertFromString(Default.clrPckerTextBoxBorder);

But it makes no change in combo box background color and border brush color. Can anybody help me know where is wrong with my codes? Thanks...

To add or overwrite existing resource, you need to set the value to resources itself instread of the variable obtained from the resources. In this case, this.Resources["TextBoxBackgroundColor"] = new SolidColorBrush((Color)ColorConverter.ConvertFromString(Default.clrPckerTextBoxBackground)); — emoacht, Dec 20 '21 at 10:01

Apurv Kumar · Answer 1 · 2021-12-21T05:28:50.773

0

Try removing and adding into the current Resources like this:

this.Resources.Remove("KeyName");
this.Resources.Add("KeyName", (Color)ColorConverter.ConvertFromString("ColorValue"));

Ideally, you could group your brushes into different merged dictionaries (with repeated keys but different brush values for the SolidColorBrushes) and remove+ add them as a group to swap them at one go.

edited Dec 21 '21 at 05:28

answered Dec 21 '21 at 05:12

Apurv Kumar

56
4

Can you explain more، please? – bername saz Dec 21 '21 at 07:06
Try something like this:- var brush7 = this.Resources["TextBoxBackgroundColor"] as SolidColorBrush; if (!string.IsNullOrEmpty(Default.clrPckerTextBoxBackground)) { this.Resources.Remove("TextBoxBackgroundColor"); this.Resources.Add("TextBoxBackgroundColor", (Color)ColorConverter.ConvertFromString(Default.clrPckerTextBoxBackground)); } – Apurv Kumar Dec 21 '21 at 12:22
But since you have 3 brushes only, it's fine. But if you want to do it at a larger scale, then add brush resources in different Xamls and add/remove Merged Dictionaries at application level instead of resource level, checkout this [StackOverflow Link](https://stackoverflow.com/questions/9739032/set-up-application-resources-from-code) – Apurv Kumar Dec 21 '21 at 12:32

how to change combo box background color in WPF?

1 Answers1