ASP.NET WEB API - 从所有自定义验证属性收集模型状态错误

I am doing a project in ASP.NET Web API. I have written different custom Validation Attributes. Now the problem is, I am getting model state errors from only one Attribute which runs first. Please help me to combine the model state errors from all validationAttributes. I am doing a project in ASP.NET Web API. I have