我有一个带有每个行删除按钮的数据，挂在删除命令上。需要单击两次按钮才能删除该行，这不是我想要的。
根据Snoop最初，根据按钮的IsEnabled == false，第一个点击可以启用它。这似乎是问题所在，那么如何在用户点击之前启用按钮？
我尝试使用触发器更改IsEnabled，在下面的代码中注释，它无效。
window1.xaml
<Window x:Class="WpfApp1.Window1"
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:WpfApp1"
mc:Ignorable="d"
Title="Window1" Height="450" Width="800">
<Grid>
<DataGrid HorizontalAlignment="Left" Height="399" Margin="10,10,0,0"
VerticalAlignment="Top" Width="772"
x:Name="dataGrid1"
ItemsSource="{Binding ProxyServers}"
CanUserAddRows="True"
CanUserDeleteRows="True"
>
<DataGrid.Columns>
<DataGridTemplateColumn Width="SizeToCells">
<DataGridTemplateColumn.CellStyle>
<Style TargetType="{x:Type DataGridCell}"
BasedOn="{StaticResource {x:Type DataGridCell}}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type DataGridCell}">
<Button Command="DataGrid.DeleteCommand"
IsEnabled="True" x:Name="deleteButton"
Content="X">
<!-- Make the button enable on mouse over?
Didn't work.
<Button.Style>
<Style TargetType="Button">
<Style.Triggers>
<Trigger Property="IsMouseOver"
Value="true">
<Setter Property="IsEnabled"
Value="true" />
</Trigger>
</Style.Triggers>
</Style>
</Button.Style>-->
</Button>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="IsEnabled" Value="True"/>
</Style>
</DataGridTemplateColumn.CellStyle>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
</Grid>
</Window>
window1.xaml.cs
using System.ComponentModel;
using System.Windows;
namespace WpfApp1
{
public partial class Window1 : Window
{
BindingList<Proxy> proxyServers;
public Window1()
{
InitializeComponent();
dataGrid1.DataContext = this;
proxyServers = new BindingList<Proxy>();
proxyServers.Add(new Proxy() { LocalURL = "http://localhost" });
}
public BindingList<Proxy> ProxyServers { get => proxyServers; set => proxyServers = value; }
}
public class Proxy
{
string localURL;
public string LocalURL { get => localURL; set => localURL = value; }
}
}
您是否考虑过类似的东西：
<DataGridTemplateColumn Header="Delete">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<Button Command="{Binding Deletecommand}"
，如果您希望在父视图的daracontext中使用该命令，则可以使用私人。用命令参数传递绑定的行对象。
详细说明 @andy的答案。这就是我要做的。
-
添加relayCommand(此实现在互联网周围漂浮，我相信它来自mvvmlite(：
using System; using System.Windows.Input; namespace WpfApp1 { public class RelayCommand<T> : ICommand { #region Fields readonly Action<T> _execute = null; readonly Predicate<T> _canExecute = null; #endregion #region Constructors /// <summary> /// Initializes a new instance of <see cref="DelegateCommand{T}"/>. /// </summary> /// <param name="execute">Delegate to execute when Execute is called on the command. This can be null to just hook up a CanExecute delegate.</param> /// <remarks><seealso cref="CanExecute"/> will always return true.</remarks> public RelayCommand(Action<T> execute) : this(execute, null) { } /// <summary> /// Creates a new command. /// </summary> /// <param name="execute">The execution logic.</param> /// <param name="canExecute">The execution status logic.</param> public RelayCommand(Action<T> execute, Predicate<T> canExecute) { if (execute == null) throw new ArgumentNullException("execute"); _execute = execute; _canExecute = canExecute; } #endregion #region ICommand Members ///<summary> ///Defines the method that determines whether the command can execute in its current state. ///</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> ///<returns> ///true if this command can be executed; otherwise, false. ///</returns> public bool CanExecute(object parameter) { return _canExecute == null ? true : _canExecute((T)parameter); } ///<summary> ///Occurs when changes occur that affect whether or not the command should execute. ///</summary> public event EventHandler CanExecuteChanged { add { CommandManager.RequerySuggested += value; } remove { CommandManager.RequerySuggested -= value; } } ///<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 <see langword="null" />.</param> public void Execute(object parameter) { _execute((T)parameter); } #endregion } } -
定义我自己的DeleteCommand，而不是使用DataGrid的Build-In-In-In。我在代码方面做到了这一点，但是在我的真实项目中，它正在视图模型中。
private RelayCommand<object> _DeleteCommand; public RelayCommand<object> DeleteCommand => _DeleteCommand ?? (_DeleteCommand = new RelayCommand<object>((object o) => { var proxy = o as Proxy; proxyServers.Remove(proxy); }, (object o) => { if (o is Proxy) { return true; } else { return false; } }));
我无法使用RelayCommand<Proxy>，因为新项目行不是代理对象。如果我没有新项目行，我可以使用RelayCommand<Proxy>。
-
在XAML中删除此模板定义(因为它是
ControlTemplate而不是DataTemplate，并且如果要以CommandParameter的形式将网格项目传递给命令，则似乎需要DataTemplate(<DataGridTemplateColumn.CellStyle> <Style TargetType="{x:Type DataGridCell}" BasedOn="{StaticResource {x:Type DataGridCell}}"> <Setter Property="Template"> <Setter.Value> <ControlTemplate > <Button Command="{Binding DeleteCommand,RelativeSource={RelativeSource AncestorType={x:Type Window}}}" CommandParameter="{Binding RelativeSource={RelativeSource AncestorType={x:Type local:Proxy}}}" IsEnabled="True" x:Name="deleteButton" Content="X"> </Button> </ControlTemplate> </Setter.Value> </Setter> <Setter Property="IsEnabled" Value="True"/> </Style> </DataGridTemplateColumn.CellStyle> -
添加此改为
<DataGridTemplateColumn.CellTemplate> <DataTemplate> <Button Command="{Binding DeleteCommand,RelativeSource={RelativeSource AncestorType={x:Type Window}}}" CommandParameter="{Binding}" IsEnabled="True" x:Name="deleteButton" Content="X"> </Button> </DataTemplate> </DataGridTemplateColumn.CellTemplate> </DataGridTemplateColumn>