我有两个WPF窗口,我想将上下文设置为ViewModel,但是如果我写:
this.DataContext = new myViewModel()
在我的第二个Windows CS中,这在我的代码中不起作用。我试图在XAML中放置一个绑定并连接上下文,但是当我尝试对其进行调试时,我得到了错误代码,此断点将无法运行。
BrowseDialog.xaml
<Window x:Class="TextalkApi.BrowseDialog"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:TextalkApi"
mc:Ignorable="d"
Title="BrowseDialog" Height="248.361" Width="427.459">
<Grid>
<Button Content="Browse" HorizontalAlignment="Left" Margin="267,11,0,0" VerticalAlignment="Top" Width="75"/>
<TextBox x:Name="FileDialog" HorizontalAlignment="Left" Height="23" Margin="10,10,0,0" TextWrapping="Wrap" Text="{Binding webUrl}" VerticalAlignment="Top" Width="244"/>
<Button Content="Save" HorizontalAlignment="Left" Margin="267,166,0,0" VerticalAlignment="Top" Width="75" Command="{Binding SaveCommand}" />
<TextBox HorizontalAlignment="Left" Height="23" Margin="10,38,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>
<Label Content="{Binding errorMessage}" HorizontalAlignment="Left" Margin="10,167,0,0" VerticalAlignment="Top" RenderTransformOrigin="-5.611,10.822" Width="207" Height="19"/>
</Grid>
</Window>
BrowseViewModel
using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Input;
using System.Threading;
using System.Threading.Tasks;
using System.Configuration;
using System.Collections.Specialized;
using System.IO;
namespace Data
{
public class BrowseViewModel : BaseViewModel
{
#region public variables
public string webUrl { get; set; }
public string errorMessage { get; set; }
#endregion
#region Public Commands
public ICommand SaveCommand { get; set; }
#endregion
#region Constructor
public BrowseViewModel()
{
this.SaveCommand = new RelayCommand(SaveFilePath);
}
#endregion
#region Private methods
private void SaveFilePath()
{
if (File.Exists(webUrl))
{
ConfigurationManager.AppSettings.Add("WebUrl", webUrl);
}
else
{
errorMessage = "Filen existerar ej";
}
}
#endregion
}
}
BrowseDialog.xaml.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
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.Shapes;
using System.IO;
using Data;
namespace TextalkApi
{
/// <summary>
/// Interaction logic for BrowseDialog.xaml
/// </summary>
public partial class BrowseDialog : Window
{
public BrowseDialog()
{
InitializeComponent();
this.DataContext = new BrowseViewModel();
}
}
}
BaseViewModel
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;
using PropertyChanged;
namespace Data
{
[AddINotifyPropertyChangedInterface]
public class BaseViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
}
}
您的XAML看起来正确,我高度怀疑这是ViewModel导致其无法正常工作。这样的事情应该起作用。
请注意,这在很大程度上取决于BaseViewModel的实现方式。如果可以的话,您可以分享一下,以便我将我的答案更新为正确的吗?
#region Properties
private string _webUrl;
public string WebUrl
{
get => _webUrl;
set
{
//This will change based on how you have implemented your BaseViewModel!
//The method name might be different, or have different parameters!
this.SetProperty(ref _webUrl, value, nameof(WebUrl));
//Call the save file path validation method...
SaveFilePath();
}
}
private string _errorMessage;
public string ErrorMessage
{
get => _errorMessage;
private set
{
//This will change based on how you have implemented your BaseViewModel!
//This method should call NotifyPropertyChange to notify the UI to update...
this.SetProperty(ref _errorMessage, value, nameof(ErrorMessage));
}
}
#endregion