检查 PropertyDescriptor 是否有属性

Question

I'm trying to check if a property has the DataMemberAttribute applied (using TypeDescriptor)

this is what I have now:

PropertyDescriptor targetProp = targetProps[i];

var has = argetProp.Attributes.Contains(
Attribute.GetCustomAttribute(typeof(DataMemberAttribute).Assembly,typeof(DataMemberAttribute)));

the problem is that

Attribute.GetCustomAttribute(typeof(DataMemberAttribute).Assembly,typeof(DataMemberAttribute))

returns null

Answer 1

You could use LINQ. A chain of the .OfType<T>() and .Any() extension methods would do the job just fine:

PropertyDescriptor targetProp = targetProps[i];
bool hasDataMember = targetProp.Attributes.OfType<DataMemberAttribute>().Any();

Answer 2

Found a much nicer answer in there: https://stackoverflow.com/a/2051116/605586

Basically you can just use:

bool hasDataMember = Attribute.IsDefined(property, typeof(DataMemberAttribute));

Answer 3

There are 3 ways:

• First:

   PropertyDescriptor targetProp = targetProps[i]; bool hasDataMember = targetProp.Attributes.Contains(new DataMemberAttribute());

• Second:

   PropertyDescriptor targetProp = targetProps[i]; bool hasDataMember = targetProp.Attributes.OfType<DataMemberAttribute>().Any();

• Third:

   PropertyDescriptor targetProp = targetProps[i]; bool hasDataMember = targetProp.Attributes.Matches(new DataMemberAttribute());

Best Regard!