列表视图绑定不更新视图 [英] Listview binding doesn't update the view

问题描述

我有这种设置为我的的ListView ，我试图做的绑定的在我的MVVM结构工作。

I have this setup for my ListView and I am trying to make Binding to work in my MVVM structure.

这是 XAML code：

<Window.Resources>
    <CollectionViewSource
        x:Key="DeviceList"
        Source="{Binding Path=DiscoveredDevicesList}">

    </CollectionViewSource>
</Window.Resources>
    <ListView
    Grid.Row="1" 
    Width="500"
    HorizontalAlignment="Left"
    Margin="10"
    Grid.Column="1"
    DataContext="{StaticResource DeviceList}"
    ItemsSource="{Binding}">
        <ListView.View>
            <GridView>
                <GridViewColumn Header="Device name" DisplayMemberBinding="{Binding Path=DeviceName}"/>
                <GridViewColumn Header="Rssi" DisplayMemberBinding="{Binding Path=Rssi}"/>
                <GridViewColumn Header="GPS Row" DisplayMemberBinding="{Binding Path=GpsSignal}"/>
            </GridView>
        </ListView.View>
    </ListView>

和下面是code来实现结合

And the following is the code to implement the binding

    //Constructor 
    public MainWindowViewModel()
    {
        DiscoveredDevicesList = new ObservableCollection<MyDeviceInfo>();
    }

    private ObservableCollection<MyDeviceInfo> _DiscoveredDevicesList;
    public ObservableCollection<MyDeviceInfo> DiscoveredDevicesList
    {
        get
        {
            return _DiscoveredDevicesList;
        }
        set
        {
            _DiscoveredDevicesList = value;
            OnPropertyChanged("DiscoveredDevicesList");
        }
    }

使用添加（）和清除（）更新视图如下使用时就好了：

Using Add() and Clear() updates the view just fine when used as below:

        var client = new BluetoothClient();
        DiscoveredDevicesList.Clear();
        IEnumerable<MyDeviceInfo> csaDevices = null;
        csaDevices = await DiscoverCsaDevicesAsync(client);

        foreach (var csaDevice in csaDevices)
        {
            DiscoveredDevicesList.Add(csaDevice);
            DiscoveredDevicesList.First().GpsSignal = true;
        }

所以，我可以看到从在我看来，最初的对面更改为 TURE 的 GpsSignal 的值。

不过，如果我把下面的同一行中的的OnClick 按钮不会做同样的和值保持的假，因为我没有使用任何添加（）或清除（）和我单纯依靠 OnPropertyChanged 这样的伎俩对我来说。

However, if I put the following same line in the OnClick of a button doesn't do the same and the value stays false since I am not using any Add() or Clear() and I simply rely on the OnPropertyChanged to do the trick for me.

            DiscoveredDevicesList.First().GpsSignal = true;

绑定，如按钮点击和文本块信息做工精细的休息，那么我认为它不应该与实施在舞台背面的结合问题。

The rest of the bindings such as button clicks and textblock information work fine, then I would assume it shouldn't be the problem with implementation of the binding on the back of the stage.

应该AP preciate你对这个建议。

Would appreciate your suggestions on this.

推荐答案

如果您MyDeviceInfo类实现INotifyPropertyChanged和你的财产GpsSignal提高OnPropertyChanged（），你应该看到所有的变化，当你绑定是正确的。

if your MyDeviceInfo class implement INotifyPropertyChanged and your property GpsSignal raise OnPropertyChanged() you should see all changes when your bindings are right.

不过我会改变你的code是这样的：

nevertheless i would change your code in this way:

从资源删除CollectionViewSource和使用简单的结合

remove CollectionViewSource from your resources and use simple binding

<Window.Resources>

</Window.Resources>
<ListView ItemsSource="{Binding DeviceList}">
    <ListView.View>
        <GridView>
            <GridViewColumn Header="Device name" DisplayMemberBinding="{Binding Path=DeviceName}"/>
            <GridViewColumn Header="Rssi" DisplayMemberBinding="{Binding Path=Rssi}"/>
            <GridViewColumn Header="GPS Row" DisplayMemberBinding="{Binding Path=GpsSignal}"/>
        </GridView>
    </ListView.View>
</ListView>

为你的窗口在DataContext设置为codebehind或XAML的MainWindowViewModel。
而不是使用的OnClick，请用个ICommand（RelayCommand或DelegateCommand）

set the datacontext for your window to your MainWindowViewModel in codebehind or xaml. instead of using OnClick, pls use ICommands (RelayCommand or DelegateCommand)

<Button Command="{Binding MyCommand4GpsSignalIsTrue}" />

这篇关于列表视图绑定不更新视图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！