feat: fix oversize dialog.

demo/Ursa.Demo/Dialogs/PlainDialog.axaml

@@ -9,5 +9,6 @@
              x:Class="Ursa.Demo.Dialogs.PlainDialog">
     <StackPanel>
         <Calendar SelectedDate="{Binding Date}" ></Calendar>
+        <TextBlock TextWrapping="Wrap" Text="{Binding Text}"></TextBlock>
     </StackPanel>
 </UserControl>

demo/Ursa.Demo/Dialogs/PlainDialogViewModel.cs

@@ -12,4 +12,17 @@ public class PlainDialogViewModel: ObservableObject
         get => _date;
         set => SetProperty(ref _date, value);
     }
+
+    private string? _text;
+    public string? Text
+    {
+        get => _text;
+        set => SetProperty(ref _text, value);
+    }
+
+    public PlainDialogViewModel()
+    {
+        Text =
+            "千古悠悠 有多少冤魂嗟叹 空怅望人寰无限 丛生哀怨 泣血蝇虫笑苍天 孤帆叠影锁白链 残月升骤起烈烈风 尽吹散 尽吹散 尽吹散 滂沱雨无底涧 涉激流登彼岸 奋力拨云间消得雾患 社稷安抚臣子心 长驱鬼魅不休战 看斜阳照大地阡陌 从头转";
+    }
 }

src/Ursa/Controls/OverlayShared/OverlayDialogHost.Dialog.cs

@@ -22,6 +22,8 @@ public partial class OverlayDialogHost
             SetTop(control, 0);
             return;
         }
+        control.MaxWidth = newSize.Width;
+        control.MaxHeight = newSize.Height;
         var width = newSize.Width - control.Bounds.Width;
         var height = newSize.Height - control.Bounds.Height;
         var newLeft = width * control.HorizontalOffsetRatio??0;
@@ -97,6 +99,8 @@ public partial class OverlayDialogHost
             control.Width = Bounds.Width;
             control.Height = Bounds.Height;
         }
+        control.MaxWidth = Bounds.Width;
+        control.MaxHeight = Bounds.Height;
         control.Measure(this.Bounds.Size);
         control.Arrange(new Rect(control.DesiredSize));
         SetToPosition(control);
@@ -154,6 +158,8 @@ public partial class OverlayDialogHost
             control.Width = Bounds.Width;
             control.Height = Bounds.Height;
         }
+        control.MaxWidth = Bounds.Width;
+        control.MaxHeight = Bounds.Height;
         control.Measure(this.Bounds.Size);
         control.Arrange(new Rect(control.DesiredSize));
         SetToPosition(control);