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c# - 如何在 MVVM-WPF 中获取选定的项目

转载 作者:太空狗 更新时间:2023-10-29 20:44:14 25 4
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您好,我正在使用 WPF 和 MVVM,我的应用程序中有“编辑/更新”面板,它更新网格中的选定数据。它工作正常。我想添加一个按钮“关闭按钮”和“检查用户是否选择了项目。如果他没有选择任何项目并单击“编辑按钮”,它将向用户显示一个消息框以选择一个项目编辑。我​​不清楚的是如何传递“选定的项目来做这两件事”并在关闭面板之前检查文本框字段中是否有任何文本。用户查看模型代码:

public class UserViewModel
{
private IList<User> _UsersList;
public UserViewModel()
{
_UsersList = new List<User>
{
new User { UserId = 1, FirstName = "Raj", LastName = "Beniwal", City = "Delhi", State = "DEL", Country = "INDIA" },
new User { UserId = 2, FirstName = "Mark", LastName = "henry", City = "New York", State = "NY", Country = "USA" },
new User { UserId = 3, FirstName = "Mahesh", LastName = "Chand", City = "Philadelphia", State = "PHL", Country = "USA" },
new User { UserId = 4, FirstName = "Vikash", LastName = "Nanda", City = "Noida", State = "UP", Country = "INDIA" },
new User { UserId = 5, FirstName = "Harsh", LastName = "Kumar", City = "Ghaziabad", State = "UP", Country = "INDIA" },
new User { UserId = 6, FirstName = "Reetesh", LastName = "Tomar", City = "Mumbai", State = "MP", Country = "INDIA" },
new User { UserId = 7, FirstName = "Deven", LastName = "Verma", City = "Palwal", State = "HP", Country = "INDIA" },
new User { UserId = 8, FirstName = "Ravi", LastName = "Taneja", City = "Delhi", State = "DEL", Country = "INDIA" }
};
}

public IList<User> Users
{
get { return _UsersList; }
set { _UsersList = value; }
}

private ICommand mUpdater;

public ICommand UpdateCommand
{
get
{
if (mUpdater == null)
{
mUpdater = new Updater();
}
return mUpdater;
}
set
{
mUpdater = value;
}
}

private class Updater : ICommand
{
#region ICommand Members

public bool CanExecute(object parameter)
{
return true;
}

public event EventHandler CanExecuteChanged;

public void Execute(object parameter)
{
}

#endregion
}
}

用户 View 窗口.Xaml面板 1

<dxdo:LayoutPanel Caption="Panel1" x:Name="Panel1">
<Grid Margin="0,0,0,20">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<ListView Name="UserGrid" Grid.Row="1" Margin="4,178,12,13" ItemsSource="{Binding Users}">
<ListView.View>
<GridView x:Name="grdTest">
<GridViewColumn Header="UserId" DisplayMemberBinding="{Binding UserId}" Width="50" />
<GridViewColumn Header="First Name" DisplayMemberBinding="{Binding FirstName}" Width="80" />
<GridViewColumn Header="Last Name" DisplayMemberBinding="{Binding LastName}" Width="100" />
<GridViewColumn Header="City" DisplayMemberBinding="{Binding City}" Width="80" />
<GridViewColumn Header="State" DisplayMemberBinding="{Binding State}" Width="80" />
<GridViewColumn Header="Country" DisplayMemberBinding="{Binding Country}" Width="100" />
</GridView>
</ListView.View>
</ListView>
</Grid>
</dxdo:LayoutPanel>
<dxdo:LayoutPanel x:Name="Panel3">
<Grid>
<StackPanel>
<Button Content="Edit" Height="23" HorizontalAlignment="Left" VerticalAlignment="Top" Width="141" Click="Button_Click_1" />
</StackPanel>
</Grid>
</dxdo:LayoutPanel>

面板 2:

<dxdo:LayoutPanel Caption="Panel2" x:Name="Panel2">
<Grid>
<StackPanel Margin="0,0,0,10">
<Grid Margin="0,0,0,20">
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<TextBox Grid.Row="1" Height="23" HorizontalAlignment="Left" Margin="80,7,0,0" Name="txtUserId" VerticalAlignment="Top" Width="178" Text="{Binding ElementName=UserGrid, Path=SelectedItem.UserId}" />
<TextBox Grid.Row="1" Height="23" HorizontalAlignment="Left" Margin="80,35,0,0" Name="txtFirstName" VerticalAlignment="Top" Width="178" Text="{Binding ElementName=UserGrid, Path=SelectedItem.FirstName}" />
<TextBox Grid.Row="1" Height="23" HorizontalAlignment="Left" Margin="80,62,0,0" Name="txtLastName" VerticalAlignment="Top" Width="178" Text="{Binding ElementName=UserGrid, Path=SelectedItem.LastName}" />
<Label Content="UserId" Grid.Row="1" HorizontalAlignment="Left" Margin="12,12,0,274" Name="label1" />
<Label Content="Last Name" Grid.Row="1" Height="28" HorizontalAlignment="Left" Margin="12,60,0,0" Name="label2" VerticalAlignment="Top" />
<Label Content="First Name" Grid.Row="1" Height="28" HorizontalAlignment="Left" Margin="12,35,0,0" Name="label3" VerticalAlignment="Top" />
<TextBox Grid.Row="1" Height="23" HorizontalAlignment="Left" Margin="80,143,0,0" x:Name="txtCity" VerticalAlignment="Top" Width="178" Text="{Binding SelectedItem.City, ElementName=UserGrid}" />
<Label Content="Country" Grid.Row="1" Height="28" HorizontalAlignment="Left" Margin="12,141,0,0" x:Name="label2_Copy" VerticalAlignment="Top" />
<TextBox Grid.Row="1" Height="23" HorizontalAlignment="Left" Margin="80,88,0,0" x:Name="txtCountry" VerticalAlignment="Top" Width="178" Text="{Binding SelectedItem.Country, ElementName=UserGrid}" />
<Label Content="City" Grid.Row="1" Height="28" HorizontalAlignment="Left" Margin="12,86,0,0" x:Name="label2_Copy1" VerticalAlignment="Top" />
<TextBox Grid.Row="1" Height="23" HorizontalAlignment="Left" Margin="80,115,0,0" x:Name="txtSTate" VerticalAlignment="Top" Width="178" Text="{Binding SelectedItem.State, ElementName=UserGrid}" />
<Label Content="State" Grid.Row="1" Height="28" HorizontalAlignment="Left" Margin="12,113,0,0" x:Name="label2_Copy2" VerticalAlignment="Top" />
</Grid>
<Button Content="Update" Grid.Row="1" Height="23" HorizontalAlignment="Left" Margin="310,40,0,0" Name="btnUpdate" VerticalAlignment="Top" Width="141" Command="{Binding Path=UpdateCommad}" />
<Button Content="Close" Grid.Row="1" Height="23" HorizontalAlignment="Right" VerticalAlignment="Top" Width="141" Click="Button_Click_2" />
<TextBox Width="166" Background="White" Height="33" HorizontalAlignment="Right" VerticalAlignment="Bottom" Text="{Binding Path=SelectedCustomer.LastName,Mode=OneWay,UpdateSourceTrigger=PropertyChanged}" />
</StackPanel>
</Grid>
</dxdo:LayoutPanel>

(如果您不清楚我的问题,请问我。谢谢)

最佳答案

在 ViewModel 中创建一个属性以保存选定的用户:

public User SelectedUser { get; set; }

将 ListView 的 SelectedItem 绑定(bind)到这个属性:

<ListView Name="UserGrid" ItemsSource="{Binding Users}" SelectedItem="{Binding SelectedUser}">

现在您只需检查 SelectedUser 属性是否为 null。

关于c# - 如何在 MVVM-WPF 中获取选定的项目,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18461914/

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