从ViewModel更改托管的Winform控件

时间:2013-08-08 20:58:21

标签: c# wpf

很抱歉是陈词滥调...但我对WPF和MVVM都很陌生,所以我不确定如何正确处理这个问题。我在其中一个视图中有一个WinForms控件,当我在ViewModel中引发一个事件时,我需要修改它的代码。我继承了我的视图的datacontext,因此viewmodel未在视图构造函数中定义。我该如何正确处理这个问题?我没有使用内置信使或聚合器的任何框架。我的相关代码如下。我需要从我的ViewModel中激活ChangeUrl方法。

编辑:根据HighCore的建议,我更新了我的代码。我仍然无法执行ChangeUrl方法,但是在我的ViewModel中引发了该事件。需要做哪些修改?

UserControl.xaml

<UserControl ...>
    <WindowsFormsHost>
        <vlc:AxVLCPlugin2 x:Name="VlcPlayerObject" />
    </WindowsFormsHost>
</UserControl>

UserControl.cs

public partial class VlcPlayer : UserControl
{
    public VlcPlayer()
    {
        InitializeComponent();
    }

    public string VlcUrl
    {
        get { return (string)GetValue(VlcUrlProperty); }
        set
        {
            ChangeVlcUrl(value);
            SetValue(VlcUrlProperty, value);
        }
    }

    public static readonly DependencyProperty VlcUrlProperty =
            DependencyProperty.Register("VlcUrl", typeof(string), typeof(VlcPlayer), new PropertyMetadata(null));

    private void ChangeVlcUrl(string newUrl)
    {
        //do stuff here
    }
}

view.xaml

<wuc:VlcPlayer VlcUrl="{Binding Path=ScreenVlcUrl}" />

视图模型

private string screenVlcUrl;
public string ScreenVlcUrl
{
    get { return screenVlcUrl; }
    set
    {
        screenVlcUrl = value;
        RaisePropertyChangedEvent("ScreenVlcUrl");
    }
}

1 个答案:

答案 0 :(得分:0)

绑定属性时,WPF不会执行属性设置器,而是必须在DependencyProperty声明中定义一个Callback方法:

public string VlcUrl
{
    get { return (string)GetValue(VlcUrlProperty); }
    set { SetValue(VlcUrlProperty, value); }
}

public static readonly DependencyProperty VlcUrlProperty =
        DependencyProperty.Register("VlcUrl", typeof(string), typeof(VlcPlayer), new PropertyMetadata(null, OnVlcUrlChanged));

private static void OnVlcUrlChanged(DependencyObject obj, DependencyPropertyChangedEventArgs e)
{
    var player = obj as VlcPlayer;
    if (obj == null)
       return;

    obj.ChangeVlcUrl(e.NewValue);
}

private void ChangeVlcUrl(string newUrl)
{
    //do stuff here
}