Changed null checks to make use of nameof()

src/Avalonia.Base/Threading/Dispatcher.Invoke.cs

@@ -90,7 +90,7 @@ public partial class Dispatcher
     {
         if (callback == null)
         {
-            throw new ArgumentNullException("callback");
+            throw new ArgumentNullException(nameof(callback));
         }
 
         DispatcherPriority.Validate(priority, "priority");
@@ -212,7 +212,7 @@ public partial class Dispatcher
     {
         if (callback == null)
         {
-            throw new ArgumentNullException("callback");
+            throw new ArgumentNullException(nameof(callback));
         }
 
         DispatcherPriority.Validate(priority, "priority");
@@ -304,7 +304,7 @@ public partial class Dispatcher
     {
         if (callback == null)
         {
-            throw new ArgumentNullException("callback");
+            throw new ArgumentNullException(nameof(callback));
         }
 
         DispatcherPriority.Validate(priority, "priority");
@@ -379,7 +379,7 @@ public partial class Dispatcher
     {
         if (callback == null)
         {
-            throw new ArgumentNullException("callback");
+            throw new ArgumentNullException(nameof(callback));
         }
 
         DispatcherPriority.Validate(priority, "priority");

src/Avalonia.Base/Threading/DispatcherTimer.cs

@@ -62,7 +62,7 @@ public partial class DispatcherTimer
     {
         if (callback == null)
         {
-            throw new ArgumentNullException("callback");
+            throw new ArgumentNullException(nameof(callback));
         }
 
         Tick += callback;
@@ -253,7 +253,7 @@ public partial class DispatcherTimer
     {
         if (dispatcher == null)
         {
-            throw new ArgumentNullException("dispatcher");
+            throw new ArgumentNullException(nameof(dispatcher));
         }
 
         DispatcherPriority.Validate(priority, "priority");

src/Avalonia.Controls.DataGrid/DataGridCheckBoxColumn.cs

@@ -222,7 +222,7 @@ namespace Avalonia.Controls
         {
             if (element == null)
             {
-                throw new ArgumentNullException("element");
+                throw new ArgumentNullException(nameof(element));
             }
             if (element is CheckBox checkBox)
             {

src/Avalonia.Controls.DataGrid/DataGridColumnCollection.cs

@@ -191,7 +191,7 @@ namespace Avalonia.Controls
                 }
                 if (dataGridColumn == null)
                 {
-                    throw new ArgumentNullException("dataGridColumn");
+                    throw new ArgumentNullException(nameof(dataGridColumn));
                 }
 
                 int columnIndexWithFiller = columnIndex;

src/Avalonia.Controls.DataGrid/DataGridLength.cs

@@ -499,7 +499,7 @@ namespace Avalonia.Controls
         {
             if (destinationType == null)
             {
-                throw new ArgumentNullException("destinationType");
+                throw new ArgumentNullException(nameof(destinationType));
             }
             if (destinationType != typeof(string))
             {

src/Avalonia.Controls/Automation/Peers/ControlAutomationPeer.cs

@@ -18,7 +18,7 @@ namespace Avalonia.Automation.Peers
 
         public ControlAutomationPeer(Control owner)
         {
-            Owner = owner ?? throw new ArgumentNullException("owner");
+            Owner = owner ?? throw new ArgumentNullException(nameof(owner));
             Initialize();
         }