BUG：BiLevel.Threshold

[waydalee]

DocumentFormat.OpenXml.Drawing.BiLevel.Threshold属性不应该是int类型，应该是string类型；（50%）
这是官方文档关于该属性的说明：

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The property should not be of type int, it should be of type string; (50%) This is the explanation of this property in the official documentation.

https://learn.microsoft.com/zh-cn/dotnet/api/documentformat.openxml.drawing.bilevel?view=openxml-3.0.1

https://learn.microsoft.com/en-us/openspecs/office_standards/ms-oi29500/1c25f0ef-b879-47f0-af0c-b1b0d40f7d05

这是真实案例：

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Here is a real-life case:

这是程序的异常信息：

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This is the program's exception information

System.FormatException: The input string '50%' was not in a correct format.

[mkaszewiak]

Hi @waydalee thank you for reporting this.
Could you please share code snippet which is causing System.FormatException?

We reviewed the issue you have reported and SDK is behaving the same way the MS Office does - Allow to read trailing percentage and allow to write as a 1000th only.

Office will read percentages formatted with a trailing percent sign or formatted as 1000th of a percent without a trailing percent sign, but only write percentages as 1000th's of a percent without a trailing percent sign.
https://learn.microsoft.com/en-us/openspecs/office_standards/ms-oi29500/1c25f0ef-b879-47f0-af0c-b1b0d40f7d05

Please share code sample so we can investigate it further. Thanks