c# - 公开 WPF 用户控件的属性

Question

我在 WPF 中有一个用户控件，它基本上是在一个 Pane 中显示文件夹树，而另一个 Pane ( ListView )显示该目录中的文件。

现在我公开了一个名为 fileextensionfilter 的属性，它基本上只需要在 ListView 中显示特定文件。例如如果 fileextensionfilter= XML 它只显示 xml 文件。

现在在我的主应用程序中，我三次使用上述控件，但是使用不同的文件扩展文件，例如 1>xml 另一个实例 .pdf 等等......

现在我从 settings.default.xmlfilter、settings.default.PDFFilter 等获取扩展过滤器值......

这里的问题是当我加载 usercontrol 的控件属性时未初始化并且我在构造函数中有一些使用此属性的东西并且(当时为“null”)所以过滤器无法在第一次工作。接下来再次刷新，过滤器属性将得到应用，因​​此它可以工作。

Answer 1

您可以尝试使用您当前的属性并使用 Loaded运行您当前在构造函数中运行的代码的事件。这是一个小例子:

MainWindow.xaml

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525" xmlns:my="clr-namespace:WpfApplication1">
    <Grid>
        <my:UserControl1 FileExtensionFilter="RTF" HorizontalAlignment="Left" Margin="10,10,0,0" x:Name="userControl1" VerticalAlignment="Top" />
        <my:UserControl1 FileExtensionFilter="XML" HorizontalAlignment="Left" Margin="10,10,0,0" x:Name="userControl2" VerticalAlignment="Top" />
        <my:UserControl1 FileExtensionFilter="PDF" HorizontalAlignment="Left" Margin="10,10,0,0" x:Name="userControl3" VerticalAlignment="Top" />
    </Grid>
</Window>

用户控件

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;

namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for UserControl1.xaml
    /// </summary>
    public partial class UserControl1 : UserControl
    {
        string filter = "NULL";
        public UserControl1()
        {
            InitializeComponent();
            System.Diagnostics.Debug.WriteLine("Property" + filter + "Set during Constructor");
        }

        public string FileExtensionFilter
        {
            get { return filter; }
            set { filter = value; }
        }

        private void UserControl_Loaded(object sender, RoutedEventArgs e)
        {
            System.Diagnostics.Debug.WriteLine("Property" + filter + "Set during Loaded");
        }

        private void UserControl_Initialized(object sender, EventArgs e)
        {
            System.Diagnostics.Debug.WriteLine("Property" + filter + "Set during Initialized");
        }
    }
}

输出

PropertyNULLSet during Initialized
PropertyNULLSet during Constructor
PropertyNULLSet during Initialized
PropertyNULLSet during Constructor
PropertyNULLSet during Initialized
PropertyNULLSet during Constructor
PropertyRTFSet during Loaded
PropertyXMLSet during Loaded
PropertyPDFSet during Loaded