# Multiple

- **功能描述:** 指定数字的值必须是Mutliple提供的值的整数倍。
- **使用位置:** UPROPERTY
- **引擎模块:** Numeric Property
- **元数据类型:** int32
- **限制类型:** int32
- **常用程度:** ★★★

指定数字的值必须是Mutliple提供的值的整数倍。

## 测试代码:

```cpp
public:
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MultipleTest)
	int32 MyInt_NoMultiple = 100;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = MultipleTest, meta = (Multiple = 5))
	int32 MyInt_HasMultiple = 100;
```

## 蓝图效果:

可以看到,拥有Multiple 的只能按照5的倍数来增长。

![Multiple](Multiple.gif)

## 原理:

```cpp
template <typename Type>
static Type ClampIntegerValueFromMetaData(Type InValue, FPropertyHandleBase& InPropertyHandle, FPropertyNode& InPropertyNode)
{
	Type RetVal = ClampValueFromMetaData<Type>(InValue, InPropertyHandle);

	//if there is "Multiple" meta data, the selected number is a multiple
	const FString& MultipleString = InPropertyHandle.GetMetaData(TEXT("Multiple"));
	if (MultipleString.Len())
	{
		check(MultipleString.IsNumeric());
		Type MultipleValue;
		TTypeFromString<Type>::FromString(MultipleValue, *MultipleString);
		if (MultipleValue != 0)
		{
			RetVal -= Type(RetVal) % MultipleValue;
		}
	}

	return RetVal;
}
```