一个WPF用户控件如何继承一个WPF用户控件？ [英] How can a WPF UserControl inherit a WPF UserControl?

问题描述

下面的WPF用户控件名为 DataTypeWholeNumber 这工作。

现在我想打一个叫做用户控件的 DataTypeDateTime 和 DataTypeEmail 等。

许多依赖属性将被所有这些控制共享的，所以我想提出的他们共同的方法到BaseDataType 并有每个用户控件从这个基类继承。

然而，当我这样做，我得到的的错误：部分声明可能不会有不同的基类的

所以，我怎么能实现与用户控件，以便共享的功能继承所有基类？

 使用System.Windows;
使用System.Windows.Controls的;命名空间TestDependencyProperty827.DataTypes
{
    公共部分类DataTypeWholeNumber：BaseDataType
    {
        公共DataTypeWholeNumber（）
        {
            的InitializeComponent（）;
            的DataContext =这一点;            //默认
            TheWidth = 200;
        }        公共字符串TheLabel
        {
            得到
            {
                返回（串）的GetValue（TheLabelProperty）;
            }
            组
            {
                的SetValue（TheLabelProperty，值）;
            }
        }        公共静态只读的DependencyProperty TheLabelProperty =
            DependencyProperty.Register（TheLabel的typeof（串）的typeof（BaseDataType）
            新FrameworkPropertyMetadata（））;
        公共字符串TheContent
        {
            得到
            {
                返回（串）的GetValue（TheContentProperty）;
            }
            组
            {
                的SetValue（TheContentProperty，值）;
            }
        }        公共静态只读的DependencyProperty TheContentProperty =
            DependencyProperty.Register（TheContent的typeof（串）的typeof（BaseDataType）
            新FrameworkPropertyMetadata（））;
        公众诠释TheWidth
        {
            得到
            {
                返回（INT）的GetValue（TheWidthProperty）;
            }
            组
            {
                的SetValue（TheWidthProperty，值）;
            }
        }        公共静态只读的DependencyProperty TheWidthProperty =
            DependencyProperty.Register（TheWidth的typeof（INT）的typeof（DataTypeWholeNumber）
            新FrameworkPropertyMetadata（））;    }
}
 

解决方案

确保您已在XAML改变了首个标记也将从新的基本类型继承

所以

 ＆LT;用户控件X：类=TestDependencyProperty827.DataTypes.DataTypeWholeNumber
    的xmlns =htt​​p://schemas.microsoft.com/winfx/2006/xaml/$p$psentation
    的xmlns：X =htt​​p://schemas.microsoft.com/winfx/2006/xaml
    的xmlns：S =CLR的命名空间：系统;装配= mscorlib程序
    ＆GT;
 

变为

 ＆LT; myTypes：BaseDataType X：类=TestDependencyProperty827.DataTypes.DataTypeWholeNumber
    的xmlns =htt​​p://schemas.microsoft.com/winfx/2006/xaml/$p$psentation
    的xmlns：X =htt​​p://schemas.microsoft.com/winfx/2006/xaml
    的xmlns：S =CLR的命名空间：系统;装配= mscorlib程序
    的xmlns：myTypes =CLR的命名空间：TestDependencyProperty827.DataTypes
    ＆GT;
 

---

所以，总结一下完整的答案，包括从下面的评论中额外的细节：

• 的基类不应该包括XAML文件。它定义在一个单一的（非局部）CS文件并定义它直接从用户控件继承。


• 确保从子类无论在CS code隐藏文件和XAML的第一个标签的基类继承（如上图所示）。

The following WPF UserControl called DataTypeWholeNumber which works.

Now I want to make a UserControl called DataTypeDateTime and DataTypeEmail, etc.

Many of the Dependency Properties will be shared by all these controls and therefore I want to put their common methods into a BaseDataType and have each of these UserControls inherit from this base type.

However, when I do that, I get the error: Partial Declaration may not have different base classes.

So how can I implement inheritance with UserControls so shared functionality is all in the base class?

using System.Windows;
using System.Windows.Controls;

namespace TestDependencyProperty827.DataTypes
{
    public partial class DataTypeWholeNumber : BaseDataType
    {
        public DataTypeWholeNumber()
        {
            InitializeComponent();
            DataContext = this;

            //defaults
            TheWidth = 200;
        }

        public string TheLabel
        {
            get
            {
                return (string)GetValue(TheLabelProperty);
            }
            set
            {
                SetValue(TheLabelProperty, value);
            }
        }

        public static readonly DependencyProperty TheLabelProperty =
            DependencyProperty.Register("TheLabel", typeof(string), typeof(BaseDataType),
            new FrameworkPropertyMetadata());


        public string TheContent
        {
            get
            {
                return (string)GetValue(TheContentProperty);
            }
            set
            {
                SetValue(TheContentProperty, value);
            }
        }

        public static readonly DependencyProperty TheContentProperty =
            DependencyProperty.Register("TheContent", typeof(string), typeof(BaseDataType),
            new FrameworkPropertyMetadata());


        public int TheWidth
        {
            get
            {
                return (int)GetValue(TheWidthProperty);
            }
            set
            {
                SetValue(TheWidthProperty, value);
            }
        }

        public static readonly DependencyProperty TheWidthProperty =
            DependencyProperty.Register("TheWidth", typeof(int), typeof(DataTypeWholeNumber),
            new FrameworkPropertyMetadata());



    }
}

解决方案

Ensure that you have changed the first tag in the xaml to also inherit from your new basetype

So

<UserControl x:Class="TestDependencyProperty827.DataTypes.DataTypeWholeNumber"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"        
    xmlns:s="clr-namespace:System;assembly=mscorlib"
    >

becomes

<myTypes:BaseDataType x:Class="TestDependencyProperty827.DataTypes.DataTypeWholeNumber"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"        
    xmlns:s="clr-namespace:System;assembly=mscorlib"
    xmlns:myTypes="clr-namespace:TestDependencyProperty827.DataTypes"
    >

---

So, to summarise the complete answer including the extra details from the comments below:

• The base class should not include a xaml file. Define it in a single (non-partial) cs file and define it to inherit directly from Usercontrol.
• Ensure that the subclass inherits from the base class both in the cs code-behind file and in the first tag of the xaml (as shown above).

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