DataType vs UiHint

问题:

I have been using mvc2 for a while now, and when i need to set the template i use the DataType Attribute

    [DataType("DropDown")]
    public int Field { get; set; }

I see others using UiHint to achieve the same results

    [UiHint("DropDown")]
    public int Field { get; set; }

What is the difference between using these two attributes? Which attribute should I be normally using, or are they for different tasks?

回答1:

DataType is generally used to make it known that this is a very specific version of a property, such as price.

The most common example of DataType is the [DataType(DataTypes.EmailAddress)] which usually is a string but we're saying that this is a very specific type of string.

They're both helpful and the UIHint overrides the DataType. So if you have a certain DataType but you want to override the editor for that specific property you can use a UIHint.

回答2:

DataType attribute has two purposes

Provide additional type information for a data field. You do this by applying the DataTypeAttribute attribute to a data field in the data model and by specifying the additional type name from the DataType enumeration. Then the view engine uses the default template for displaying the property, like, a checkbox for a boolean.

If you want to override the default template, and wish to use a custom template, then it can be used to associate a custom field template with that data field. In this case you must provide a partial page[.cshtml, MVC 4] to describe the display.

The purpose of UIHint is exactly same as the second point above. Where to use what? The answer is: context, ie., what will make more sense, what is closer to the physical problem your code is trying to solve. What if both are applied to the same property? The answer is: UIHint has precedence, obviously. But why would you apply both?