部分声明，不得指定不同的基类

Question

我知道互联网上有这方面的信息，我已经搜索过了。但我仍然收到错误，谁能指出我做错了什么？

基类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Controls;

namespace ProgramManagementV2.screens
{
    public abstract class AScreenUserControl : UserControl
    {
        public string GetScreenDescriptionName()
        {
            return "No name yet!";
        }
    }
}

MainUserControl.xaml

<UserControl x:Class="ProgramManagementV2.screens.MainUserControl"
             xmlns:we="clr-namespace:ProgramManagementV2.screens"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <TextBlock Height="23" HorizontalAlignment="Center" Name="textBlock1" Text="asdfasdf" VerticalAlignment="Center" />
    </Grid>
</UserControl>

MainUserControl.xaml.cs：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.ComponentModel;

namespace ProgramManagementV2.screens
{
    /// <summary>
    /// Interaction logic for MainUserControl.xaml
    /// </summary>
    public partial class MainUserControl : AScreenUserControl
    {
        public MainUserControl()
        {
            InitializeComponent();
        }
    }
}

如你所见，我正在添加

xmlns:we="clr-namespace:ProgramManagementV2.screens"

到用户控件 xml，但我仍然收到错误：

“ProgramManagementV2.screens.MainUserControl”的部分声明不得指定不同的基类

谁能向我解释我做错了什么？

Answer 1

通过使用<UserControl ...，您将基类声明为UserControl，您需要将其更改为

<we:AScreenUserControl x:Class="ProgramManagementV2.screens.MainUserControl" ...

但是我认为UserControls 只允许一级继承，至少如果AScreenUserControl 有 XAML，这肯定行不通。

Answer 2

这样做：

<we:AScreenUserControl x:Class="ProgramManagementV2.screens.MainUserControl"
             xmlns:we="clr-namespace:ProgramManagementV2.screens"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <TextBlock Height="23" HorizontalAlignment="Center" Name="textBlock1" Text="asdfasdf" VerticalAlignment="Center" />
    </Grid>
</we:AScreenUserControl>