vault backup: 2024-10-12 17:19:45

03-UnrealEngine/Gameplay/UObject/UnrealSpecifiers/Meta/Numeric/HideAlphaChannel/HideAlphaChannel.md

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+# HideAlphaChannel
+
+- **功能描述：** 使FColor或FLinearColor属性在编辑的时候隐藏Alpha通道。
+- **使用位置：** UPROPERTY
+- **引擎模块：** Numeric Property
+- **元数据类型：** bool
+- **限制类型：** FColor , FLinearColor 
+- **常用程度：** ★★★
+
+使FColor或FLinearColor属性在编辑的时候隐藏Alpha通道。
+
+## 测试代码：
+
+```cpp
+public:
+	UPROPERTY(EditAnywhere, Category = AlphaTest)
+	FColor MyColor;
+
+	UPROPERTY(EditAnywhere, Category = AlphaTest, meta = (HideAlphaChannel))
+	FColor MyColor_HideAlphaChannel;
+
+	UPROPERTY(EditAnywhere, Category = AlphaTest)
+	FLinearColor MyLinearColor;
+
+	UPROPERTY(EditAnywhere, Category = AlphaTest, meta = (HideAlphaChannel))
+	FLinearColor MyLinearColor_HideAlphaChannel;
+```
+
+## 测试结果：
+
+可见带有HideAlphaChannel的属性就没有了Alpha通道。
+
+![Untitled](Untitled.png)
+
+## 原理：
+
+```cpp
+void FColorStructCustomization::CustomizeHeader(TSharedRef<class IPropertyHandle> InStructPropertyHandle, class FDetailWidgetRow& InHeaderRow, IPropertyTypeCustomizationUtils& StructCustomizationUtils)
+{
+	bIgnoreAlpha = TypeSupportsAlpha() == false || StructPropertyHandle->GetProperty()->HasMetaData(TEXT("HideAlphaChannel"));
+}
+
+.AlphaDisplayMode(bIgnoreAlpha ? EColorBlockAlphaDisplayMode::Ignore : EColorBlockAlphaDisplayMode::Separate)
+
+```