53 lines
1.3 KiB
Markdown
53 lines
1.3 KiB
Markdown
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# Multiple
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- **功能描述：** 指定数字的值必须是Mutliple提供的值的整数倍。
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- **使用位置：** UPROPERTY
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- **引擎模块：** Numeric Property
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- **元数据类型：** int32
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- **限制类型：** int32
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- **常用程度：** ★★★
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指定数字的值必须是Mutliple提供的值的整数倍。
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## 测试代码：
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```cpp
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public:
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UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MultipleTest)
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int32 MyInt_NoMultiple = 100;
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UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MultipleTest, meta = (Multiple = 5))
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int32 MyInt_HasMultiple = 100;
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```
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## 蓝图效果：
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可以看到，拥有Multiple 的只能按照5的倍数来增长。
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## 原理：
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```cpp
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template <typename Type>
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static Type ClampIntegerValueFromMetaData(Type InValue, FPropertyHandleBase& InPropertyHandle, FPropertyNode& InPropertyNode)
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{
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Type RetVal = ClampValueFromMetaData<Type>(InValue, InPropertyHandle);
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//if there is "Multiple" meta data, the selected number is a multiple
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const FString& MultipleString = InPropertyHandle.GetMetaData(TEXT("Multiple"));
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if (MultipleString.Len())
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{
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check(MultipleString.IsNumeric());
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Type MultipleValue;
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TTypeFromString<Type>::FromString(MultipleValue, *MultipleString);
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if (MultipleValue != 0)
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{
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RetVal -= Type(RetVal) % MultipleValue;
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}
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}
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return RetVal;
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}
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```
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