# CustomRequestFormat `Get|Let {String}` 使用在[`WebHelpers.RegisterConverter`](RegisterConverter.md)中注册的转换器将`Body`转换为字符串并设置`Content-Type`标头。 (自动将`RequestFormat`设置为`WebFormat.Custom`) ~~~ WebHelpers.RegisterConverter "csv", "text/csv", "Module.ConvertToCSV", "Module.ParseCSV" Dim Request As New WebRequest Request.CustomRequestFormat = "csv" '// -> Content-Type: "text/csv" '// -> Body converted to string with Module.ConvertToCSV ~~~