How to set Default value as Empty string in Model in asp.net mvc application
Is there any way that can I set default value as开发者_如何转开发 Empty.string in Model.
I have a column Name in the Model its not null field in the database with default value is Empty.string
is there any way that I can set this default property in the Model for this column?
Thanks
There is a setting for this which you can configure by overriding the default model binder as follows:
public sealed class EmptyStringModelBinder : DefaultModelBinder
{
public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
bindingContext.ModelMetadata.ConvertEmptyStringToNull = false;
return base.BindModel(controllerContext, bindingContext);
}
}
then configure this as the default model binder in application start in the global.asax:
ModelBinders.Binders.DefaultBinder = new EmptyStringModelBinder();
and there you go, no more null strings.
MyProperty {get{return myProperty??""}}
A cleaner alternative is to provide a custom ModelMetadataProvider instead of creating a ModelBinder which modifies the ModelMetadata.
public class EmptyStringDataAnnotationsModelMetadataProvider : System.Web.Mvc.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;
}
}
Then in Application_Start()
ModelMetadataProviders.Current = new EmptyStringDataAnnotationsModelMetadataProvider();
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