创建UserControl DependencyProperty，可以在下拉列表中选择其值（如组合框） [英] Create UserControl DependencyProperty of which value can be chosen in dropdown list (as combo box)

问题描述

我是WPF的入门者，现在我想制作一个WPF userControl库，其中包括一个评级栏userControl。创建评级栏的所有步骤均已完成，但是我想添加一个属性RatingValue：

I'm a starter at WPF, now i would like to make a WPF userControl library which include a Rating bar userControl. All the steps of creating the rating Bar has been done, however i would like to add a property RatingValue:

public static readonly DependencyProperty RatingValueProperty =
            DependencyProperty.Register("RatingValue", typeof(int), typeof(RatingControl),
            new FrameworkPropertyMetadata(0, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault, new PropertyChangedCallback(RatingValueChanged)));

public int RatingValue
        {
            get { return (int)GetValue(RatingValueProperty); }
            set
            {               
                SetValue(RatingValueProperty, value);                
            }
        }

private static void RatingValueChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
        {
         //... change the rating value
        }

我的UserControl的用户可以修改0到5之间的值，如下所示属性窗口中的下拉列表（组合框）（某些用户控件的属性如可见性，Windows样式，背景...）

that the user of my UserControl can modify by a value from 0 to 5 that are shown in a dropdown list (combo box) in the Properties windows (as some exist properties of Usercontrols like Visibility, windows style, background ...)

我该怎么办？
非常感谢，

How can i do? Thank you very much in advance,

越南语

推荐答案

1. 创建一个从TypeConverter派生的类。


2. 覆盖GetStandardValues和GetStandardValuesSupported（以及可选的GetStandardValuesExclusive）。


3. 从GetStandardValues ，返回一个包含要显示在组合框中的值的集合。


4. 将TypeConverterAttribute应用于RatingValue属性，指定类型转换器的类型。

1. Create a class derived from TypeConverter.
2. Override GetStandardValues and GetStandardValuesSupported (and optionally GetStandardValuesExclusive).
3. From GetStandardValues, return a collection containing the values you want to appear in the combo box.
4. Apply TypeConverterAttribute to the RatingValue property, specifying the type of your type converter.

或者，根据RatingValue的语义，您可以考虑将其设为枚举。因为值是数字，所以感觉有点奇怪-但这将具有在类型级别上约束值的优势，并且它会自动为您提供一个组合框，而无需您实现类型转换器。

Alternatively, depending on the semantics of RatingValue, you might consider making it an enum. This feels a bit weird because the values are numeric -- but it would have the advantage of constraining the values at a type level, and it would automatically give you a combo box with no need for you to implement a type converter.

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