From 518f216f7729afc35f3358d7559d392a5bc6e006 Mon Sep 17 00:00:00 2001
From: Corvin <43533385+corvinsz@users.noreply.github.com>
Date: Tue, 8 Sep 2026 16:21:27 +0200
Subject: [PATCH] fix(combobox): allow dropdown toggle when clicking prefix or
 suffix text

---
 .../Themes/MaterialDesignTheme.ComboBox.xaml  |  2 ++
 .../WPF/ComboBoxes/ComboBoxTests.cs           | 35 +++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.ComboBox.xaml b/src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.ComboBox.xaml
index 5746b3ddd4..72a49c8da4 100644
--- a/src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.ComboBox.xaml
+++ b/src/MaterialDesignThemes.Wpf/Themes/MaterialDesignTheme.ComboBox.xaml
@@ -350,6 +350,7 @@
                          Grid.Column="1"
                          Margin="0,0,2,0"
                          FontSize="{TemplateBinding FontSize}"
+                         IsHitTestVisible="False"
                          Opacity="{TemplateBinding wpf:HintAssist.HintOpacity}"
                          Text="{TemplateBinding wpf:TextFieldAssist.PrefixText}"
                          VerticalAlignment="Center">
@@ -446,6 +447,7 @@
                          Grid.Column="3"
                          Margin="2,0,0,0"
                          FontSize="{TemplateBinding FontSize}"
+                         IsHitTestVisible="False"
                          Opacity="{TemplateBinding wpf:HintAssist.HintOpacity}"
                          Text="{TemplateBinding wpf:TextFieldAssist.SuffixText}"
                          VerticalAlignment="Center">
diff --git a/tests/MaterialDesignThemes.UITests/WPF/ComboBoxes/ComboBoxTests.cs b/tests/MaterialDesignThemes.UITests/WPF/ComboBoxes/ComboBoxTests.cs
index c784351d2e..6dec4654c4 100644
--- a/tests/MaterialDesignThemes.UITests/WPF/ComboBoxes/ComboBoxTests.cs
+++ b/tests/MaterialDesignThemes.UITests/WPF/ComboBoxes/ComboBoxTests.cs
@@ -299,4 +299,39 @@ public async Task ComboBox_UsesDropDownBackgroundResource_WhenBackgroundIsNotSet
         await Assert.That(popupBackground).IsNotNull();
         await Assert.That(popupBackground).IsEqualTo((Color)ColorConverter.ConvertFromString("#CC336699"));
     }
+
+    [Test]
+    [Description("https://github.com/MaterialDesignInXAML/MaterialDesignInXamlToolkit/issues/4090")]
+    public async Task ComboBox_OpensDropDown_WhenClickingOnPrefixOrSuffixTextBlock()
+    {
+        var comboBox = await LoadXaml<ComboBox>($"""
+            <ComboBox materialDesign:TextFieldAssist.PrefixText="Some prefix"
+                      materialDesign:TextFieldAssist.SuffixText="Some suffix"
+                      SelectedIndex="1">
+                <ComboBoxItem Content="Android" />
+                <ComboBoxItem Content="iOS" />
+                <ComboBoxItem Content="Linux" />
+                <ComboBoxItem Content="Windows" />
+            </ComboBox>
+            """);
+
+        await Assert.That(await comboBox.GetIsDropDownOpen()).IsFalse();
+
+        var prefixTextBlock = await comboBox.GetElement<TextBlock>("PrefixTextBlock");
+        await AssertOpensAndClosesDropDown(prefixTextBlock);
+
+        var suffixTextBlock = await comboBox.GetElement<TextBlock>("SuffixTextBlock");
+        await AssertOpensAndClosesDropDown(suffixTextBlock);
+
+        async Task AssertOpensAndClosesDropDown(IVisualElement<TextBlock> textBlock)
+        {
+            await textBlock.LeftClick();
+            await Task.Delay(50, TestContext.Current!.Execution.CancellationToken);
+            await Assert.That(await comboBox.GetIsDropDownOpen()).IsTrue();
+
+            await textBlock.LeftClick();
+            await Task.Delay(50, TestContext.Current!.Execution.CancellationToken);
+            await Assert.That(await comboBox.GetIsDropDownOpen()).IsFalse();
+        }
+    }
 }