如何使用WPF为DataGrid上的每个记录添加删除按钮？ [英] How to add a delete button for every record on a DataGrid using WPF?
本文介绍了如何使用WPF为DataGrid上的每个记录添加删除按钮？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我试图在DataGrid中显示记录，并且对于网格上的每一行，我想显示一个删除记录的按钮。
I am trying to display record in a DataGrid and for each row on the grid, I want to show a button to delete that record.
我添加了按钮成功到dataGrid。但是，在加载视图时，将为每个记录调用删除命令。换句话说，我确认对话框出现10次，因为我要显示10条记录。
I added the button successfully to the dataGrid. However, when the view is loaded, the "delete" command is called for every record. In another word, I the confirm dialog appears 10 time because I have 10 records to display.
问题
如何防止从每次执行该命令，只允许它在单击按钮时运行？
另外，如何将最后两列一直移到最右边，使它们垂直对齐？
Questions How to I prevent the command from being executed each time and only allow it to run on button click? Also, how can I move the last 2 column all the way to the far right so they are vertically aligned?
在我的ViewModel中，添加了以下命令
In my ViewModel, I added the following command
public ICommand DeleteVendor
{
get
{
MessageBoxResult confirmation = MessageBox.Show("Are you sure?", "Delete Confirmation", MessageBoxButton.YesNo);
bool processDelete = (confirmation == MessageBoxResult.Yes);
return new ActionCommand(p => HandleDeleteVendor(), p => processDelete);
}
}
private void HandleDeleteVendor()
{
if (SelectedVendor == null)
{
throw new Exception("No vendor was selected");
}
UnitOfWork.Vendors.Remove(SelectedVendor);
UnitOfWork.Save();
}
然后在我看来，我添加了以下 XAML 代码
Then in my view I added the following XAML code
<DataGrid ItemsSource="{Binding Vendors}"
SelectedItem="{Binding SelectedVendor}"
AutoGenerateColumns="False"
HorizontalAlignment="Stretch"
VerticalAlignment="Center"
CanUserAddRows="False">
<DataGrid.Columns>
<DataGridTextColumn Header="Name"
Binding="{Binding Name}" />
<DataGridTextColumn Header="Account Number"
Binding="{Binding AccountCode}" />
<DataGridTemplateColumn>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Button VerticalAlignment="Center"
Command="{Binding RelativeSource={RelativeSource AncestorType={x:Type DataGrid}},
Path=DataContext.ShowVendor}">
<StackPanel Orientation="Horizontal">
<fa:FontAwesome Icon="Eye"
FontSize="18" />
<Label Content="Details"
Padding="7 0 0 0" />
</StackPanel>
</Button>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Button VerticalAlignment="Center"
Command="{Binding RelativeSource={RelativeSource AncestorType={x:Type DataGrid}},
Path=DataContext.DeleteVendor}">
<StackPanel Orientation="Horizontal">
<fa:FontAwesome Icon="Trash"
FontSize="18" />
<Label Content="Delete"
Padding="7 0 0 0" />
</StackPanel>
</Button>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
如果需要，这是我的 ICommand 实现
If needed here is my ICommand implementation
public sealed class ActionCommand : ICommand
{
private readonly Action<Object> Action;
private readonly Predicate<Object> Allowed;
/// <summary>
/// Initializes a new instance of the <see cref="ActionCommand"/> class.
/// </summary>
/// <param name="action">The <see cref="Action"/> delegate to wrap.</param>
public ActionCommand(Action<Object> action)
: this(action, null)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="ActionCommand"/> class.
/// </summary>
/// <param name="action">The <see cref="Action"/> delegate to wrap.</param>
/// <param name="predicate">The <see cref="Predicate{Object}"/> that determines whether the action delegate may be invoked.</param>
public ActionCommand(Action<Object> action, Predicate<Object> allowed)
{
if (action == null)
{
throw new ArgumentNullException("action", "You must specify an Action<T>.");
}
Action = action;
Allowed = allowed;
}
/// <summary>
/// Defines the method that determines whether the command can execute in its current state.
/// </summary>
/// <returns>
/// true if this command can be executed; otherwise, false.
/// </returns>
/// <param name="parameter">Data used by the command. If the command does not require data to be passed, this object can be set to null.</param>
public bool CanExecute(object parameter)
{
if (Allowed == null)
{
return true;
}
return Allowed(parameter);
}
/// <summary>
/// Defines the method to be called when the command is invoked.
/// </summary>
/// <param name="parameter">Data used by the command. If the command does not require data to be passed, this object can be set to null.</param>
public void Execute(object parameter)
{
Action(parameter);
}
/// <summary>
/// Executes the action delegate without any parameters.
/// </summary>
public void Execute()
{
Execute(null);
}
/// <summary>
/// Occurs when changes occur that affect whether the command should execute.
/// </summary>
public event EventHandler CanExecuteChanged
{
add
{
if (Allowed != null)
{
CommandManager.RequerySuggested += value;
}
}
remove
{
if (Allowed != null)
{
CommandManager.RequerySuggested -= value;
}
}
}
/// <summary>
/// Raises the <see cref="CanExecuteChanged" /> event.
/// </summary>
public void RaiseCanExecuteChanged()
{
CommandManager.InvalidateRequerySuggested();
}
}
推荐答案
确认应该是删除方法的一部分，而不是命令定义的一部分：
confirmation should be a part of delete method, not a part of command definition:
public ICommand DeleteVendor
{
get
{
return new ActionCommand(p => HandleDeleteVendor(), p => SelectedVendor != null);
}
}
private void HandleDeleteVendor()
{
MessageBoxResult confirmation = MessageBox.Show("Are you sure?", "Delete Confirmation", MessageBoxButton.YesNo);
if (confirmation != MessageBoxResult.Yes);
return;
if (SelectedVendor == null)
{
// IMO, it is better to handle this situation gracefully and show messageBox with a warning
throw new Exception("No vendor was selected");
}
UnitOfWork.Vendors.Remove(SelectedVendor);
UnitOfWork.Save();
}
这篇关于如何使用WPF为DataGrid上的每个记录添加删除按钮？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！
查看全文
