ajax post提交空字符串(string.Empty) MVC接收为null的问题

时间:2023-01-07 16:01:50

ajax post提交空字符串(string.Empty) MVC接收为null的问题

这个问题查了好多资料才知道原因:

if (bindingContext.ModelMetadata.ConvertEmptyStringToNull && Object.Equals(value, String.Empty)) {   return null; }

当Model的元数据ConvertEmptyStringToNull为true,并且form的值为空字串时,返回null.

 

解决方法:

  1、给对应的属性加上特性

[DisplayFormat(ConvertEmptyStringToNull = false)]

  2、覆写模型创建元数据的方法,

  

public class EmptyStringDataAnnotationsModelMetadataProvider : DataAnnotationsModelMetadataProvider
{
protected override ModelMetadata CreateMetadata(IEnumerable<Attribute> attributes, Type containerType, Func<object> modelAccessor, Type modelType, string propertyName)
{
var modelMetadata = base.CreateMetadata(attributes, containerType, modelAccessor, modelType, propertyName);
modelMetadata.ConvertEmptyStringToNull
= false;
return modelMetadata;
}
}

  并在Global.asax文件中进行设置

  

ModelMetadataProviders.Current = new EmptyStringDataAnnotationsModelMetadataProvider();

 

参考文章:

  1、https://*.com/questions/12734083/string-empty-converted-to-null-when-passing-json-object-to-mvc-controller

  2、https://www.cnblogs.com/lonelyxmas/p/5558885.html