From b00503fdc67e9ac637024449b6e8b06ebf9b2d7c Mon Sep 17 00:00:00 2001
From: BlueRose <378100977@qq.com>
Date: Wed, 3 Sep 2025 13:52:28 +0800
Subject: [PATCH] vault backup: 2025-09-03 13:52:28

---
 03-UnrealEngine/UI/CommonUI.md | 90 +++++++++++++++++++++++++++++++++-
 1 file changed, 89 insertions(+), 1 deletion(-)

diff --git a/03-UnrealEngine/UI/CommonUI.md b/03-UnrealEngine/UI/CommonUI.md
index 5723aa0..101bd6d 100644
--- a/03-UnrealEngine/UI/CommonUI.md
+++ b/03-UnrealEngine/UI/CommonUI.md
@@ -250,4 +250,92 @@ PS:
 
 
 ## 函数？
-KeyBoardFocus
\ No newline at end of file
+KeyBoardFocus
+
+```c++
+void UWidget::SetKeyboardFocus()
+{
+	TSharedPtr<SWidget> SafeWidget = GetCachedWidget();
+	if (SafeWidget.IsValid())
+	{
+#if !(UE_BUILD_SHIPPING || UE_BUILD_TEST)
+		if ( !SafeWidget->SupportsKeyboardFocus() )
+		{
+			FMessageLog("PIE").Warning(FText::Format(LOCTEXT("ThisWidgetDoesntSupportFocus", "The widget {0} does not support focus. If this is a UserWidget, you should set bIsFocusable to true."), FText::FromString(GetNameSafe(this))));
+		}
+#endif
+
+		if ( !FSlateApplication::Get().SetKeyboardFocus(SafeWidget) )
+		{
+			if ( UWorld* World = GetWorld() )
+			{
+				if ( ULocalPlayer* LocalPlayer = World->GetFirstLocalPlayerFromController() )
+				{
+					LocalPlayer->GetSlateOperations().SetUserFocus(SafeWidget.ToSharedRef(), EFocusCause::SetDirectly);
+				}
+			}
+		}
+	}
+}
+
+
+void UWidget::SetFocus()  
+{  
+    SetUserFocus(GetOwningPlayer());  
+}
+
+void UWidget::SetUserFocus(APlayerController* PlayerController)
+{
+	if ( PlayerController == nullptr || !PlayerController->IsLocalPlayerController() || PlayerController->Player == nullptr )
+	{
+#if !(UE_BUILD_SHIPPING || UE_BUILD_TEST)
+		FMessageLog("PIE").Error()->AddToken(FTextToken::Create(LOCTEXT("NoPlayerControllerToFocus", "The PlayerController is not a valid local player so it can't focus on ")))->AddToken(FUObjectToken::Create(this));
+#endif
+		return;
+	}
+
+	TSharedPtr<SWidget> SafeWidget = GetCachedWidget();
+	if ( SafeWidget.IsValid() )
+	{
+#if !(UE_BUILD_SHIPPING || UE_BUILD_TEST)
+		if ( !SafeWidget->SupportsKeyboardFocus() )
+		{
+			TSharedRef<FTokenizedMessage> Message = FMessageLog("PIE").Warning()->AddToken(FUObjectToken::Create(this));
+#if WITH_EDITORONLY_DATA
+			if(UObject* GeneratedBy = WidgetGeneratedBy.Get())
+			{
+				Message->AddToken(FTextToken::Create(FText::FromString(TEXT(" in "))))->AddToken(FUObjectToken::Create(GeneratedBy));
+			}
+#endif
+			if (IsA(UUserWidget::StaticClass()))
+			{
+				Message->AddToken(FTextToken::Create(LOCTEXT("UserWidgetDoesntSupportFocus", " does not support focus, you should set bIsFocusable to true.")));
+			}
+			else
+			{
+				Message->AddToken(FTextToken::Create(LOCTEXT("NonUserWidgetDoesntSupportFocus", " does not support focus.")));
+			}
+			
+		}
+#endif
+
+		if ( ULocalPlayer* LocalPlayer = PlayerController->GetLocalPlayer() )
+		{
+			TOptional<int32> UserIndex = FSlateApplication::Get().GetUserIndexForController(LocalPlayer->GetControllerId());
+			if (UserIndex.IsSet())
+			{
+				FReply& DelayedSlateOperations = LocalPlayer->GetSlateOperations();
+				if (FSlateApplication::Get().SetUserFocus(UserIndex.GetValue(), SafeWidget))
+				{
+					DelayedSlateOperations.CancelFocusRequest();
+				}
+				else
+				{
+					DelayedSlateOperations.SetUserFocus(SafeWidget.ToSharedRef());
+				}
+				
+			}
+		}
+	}
+}
+```
\ No newline at end of file