safer walking of ancestory for #234

ButchersBoy · ButchersBoy · commit 383381052a2d · 2016-01-27T17:03:31.000Z
diff --git a/MaterialDesignThemes.Wpf/DataGridAssist.cs b/MaterialDesignThemes.Wpf/DataGridAssist.cs
@@ -5,6 +5,7 @@
 using System.Windows.Data;
 using System.Windows.Input;
 using System.Windows.Media;
+using System.Windows.Media.Media3D;
 using System.Windows.Threading;
 
 namespace MaterialDesignThemes.Wpf
@@ -191,7 +192,9 @@ private static void DataGridOnPreviewMouseLeftButtonDown(object sender,
                     return;
                 }
 
-                inputHitTest = VisualTreeHelper.GetParent(inputHitTest);
+                inputHitTest = (inputHitTest is Visual || inputHitTest is Visual3D)
+                    ? VisualTreeHelper.GetParent(inputHitTest)
+                    : null;                
             }
         }
 

Original file line number	Diff line number	Diff line change
`@@ -5,6 +5,7 @@`
`5`	`5`	`using System.Windows.Data;`
`6`	`6`	`using System.Windows.Input;`
`7`	`7`	`using System.Windows.Media;`
	`8`	`+using System.Windows.Media.Media3D;`
`8`	`9`	`using System.Windows.Threading;`
`9`	`10`
`10`	`11`	`namespace MaterialDesignThemes.Wpf`
`@@ -191,7 +192,9 @@ private static void DataGridOnPreviewMouseLeftButtonDown(object sender,`
`191`	`192`	`return;`
`192`	`193`	`}`
`193`	`194`
`194`		`- inputHitTest = VisualTreeHelper.GetParent(inputHitTest);`
	`195`	`+ inputHitTest = (inputHitTest is Visual \|\| inputHitTest is Visual3D)`
	`196`	`+ ? VisualTreeHelper.GetParent(inputHitTest)`
	`197`	`+ : null;`
`195`	`198`	`}`
`196`	`199`	`}`
`197`	`200`