[英]How to Select All CheckBox of a Column on DataGrid Header CheckBox in WPF DataGrid
[英]How to Select All CheckBox of a Column by DataGrid Header CheckBox in WPF DataGrid
我有一个带有一个 CheckBoxColumn 的 DataGrid。 在 CheckBoxColumn 的标题中,我添加了一个 CheckBox 来选择该 Datagrid 行的所有复选框。
我怎样才能做到这一点?
我的 WPF 数据网格 XAML 代码:
<DataGrid AutoGenerateColumns="False" CanUserAddRows="False" Grid.RowSpan="2" Height="130" HorizontalAlignment="Left" IsReadOnly="False" Margin="189,340,0,0" Name="dgCandidate" TabIndex="7" VerticalAlignment="Top" Width="466" Grid.Row="1" >
<DataGrid.Columns>
<DataGridTextColumn x:Name="colCandidateID" Binding="{Binding CandidateID}" Header="SlNo" MinWidth="20" IsReadOnly="True" />
<DataGridTextColumn x:Name="colRegistraion" Binding="{Binding RegisterNo}" Header="Reg. No." IsReadOnly="True" />
<DataGridTextColumn x:Name="colCandidate" Binding="{Binding CandidateName}" Header="Name" MinWidth="250" IsReadOnly="True" />
<DataGridTemplateColumn>
<DataGridTemplateColumn.Header>
<CheckBox Name="chkSelectAll" Checked="chkSelectAll_Checked" Unchecked="chkSelectAll_Unchecked"></CheckBox>
</DataGridTemplateColumn.Header>
<DataGridTemplateColumn.CellTemplate >
<DataTemplate >
<CheckBox x:Name="colchkSelect1" Checked="colchkSelect1_Checked" Unchecked="colchkSelect1_Unchecked" ></CheckBox>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
将你的 Candidate 类转换成这样:
public class Candidate : DependencyObject
{
//CandidateID Dependency Property
public int CandidateID
{
get { return (int)GetValue(CandidateIDProperty); }
set { SetValue(CandidateIDProperty, value); }
}
public static readonly DependencyProperty CandidateIDProperty =
DependencyProperty.Register("CandidateID", typeof(int), typeof(Candidate), new UIPropertyMetadata(0));
//RegisterNo Dependency Property
public int RegisterNo
{
get { return (int)GetValue(RegisterNoProperty); }
set { SetValue(RegisterNoProperty, value); }
}
public static readonly DependencyProperty RegisterNoProperty =
DependencyProperty.Register("RegisterNo", typeof(int), typeof(Candidate), new UIPropertyMetadata(0));
//CandidateName Dependency Property
public string CandidateName
{
get { return (string)GetValue(CandidateNameProperty); }
set { SetValue(CandidateNameProperty, value); }
}
public static readonly DependencyProperty CandidateNameProperty =
DependencyProperty.Register("CandidateName", typeof(string), typeof(Candidate), new UIPropertyMetadata(""));
//BooleanFlag Dependency Property
public bool BooleanFlag
{
get { return (bool)GetValue(BooleanFlagProperty); }
set { SetValue(BooleanFlagProperty, value); }
}
public static readonly DependencyProperty BooleanFlagProperty =
DependencyProperty.Register("BooleanFlag", typeof(bool), typeof(Candidate), new UIPropertyMetadata(false));
}
在 MainWindow.xaml 中:
<DataGrid ItemsSource="{Binding CandidateList}">
<DataGrid.Columns>
<DataGridTextColumn Header="Id" Binding="{Binding CandidateID}"/>
<DataGridTextColumn Header="RegNr" Binding="{Binding RegisterNo}"/>
<DataGridTextColumn Header="Name" Binding="{Binding CandidateName}"/>
<DataGridTemplateColumn>
<DataGridTemplateColumn.Header>
<CheckBox Checked="CheckBox_Checked" Unchecked="CheckBox_Checked"></CheckBox>
</DataGridTemplateColumn.Header>
<DataGridTemplateColumn.CellTemplate >
<DataTemplate>
<CheckBox IsChecked="{Binding BooleanFlag}"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
在 MainWindow.xaml.cs 中:
public MainWindow()
{
DataContext = this;
CandidateList.Add(new Candidate()
{
CandidateID = 1,
CandidateName = "Jack",
RegisterNo = 123,
BooleanFlag = true
});
CandidateList.Add(new Candidate()
{
CandidateID = 2,
CandidateName = "Jim",
RegisterNo = 234,
BooleanFlag = false
});
InitializeComponent();
}
//List Observable Collection
private ObservableCollection<Candidate> _candidateList = new ObservableCollection<Candidate>();
public ObservableCollection<Candidate> CandidateList { get { return _candidateList; } }
private void CheckBox_Checked(object sender, RoutedEventArgs e)
{
foreach (var item in CandidateList)
{
item.BooleanFlag = true;
}
}
private void UnheckBox_Checked(object sender, RoutedEventArgs e)
{
foreach (var item in CandidateList)
{
item.BooleanFlag = false;
}
}
严格来说,模型不应该知道视图,因此,blinmeis 提出的解决方案,其中模型更改是更新数据网格中的每一行,打破了 MVVM/演示设计模式。 请记住,在 MVVM 中,依赖流是视图 -> 视图模型 -> 模型,因此如果您在视图模型(或控件代码隐藏)中引用控件,那么您已经有效地打破了模式,并且可能会进一步遇到问题。
我添加了 CheckBox 以选择 Datagrid Row 中的所有 CheckBox
如果您的意思是选择 datagrid列中的所有复选框,那么我会说:只需使用选中/未选中状态更新您的 itemssource 集合。
public bool SelectAll
{
get{return this._selectAll;}
set
{
this._selectAll = value;
this.MyItemsSourceCollection.ForEach(x=>x.MyRowCheckProperty=value);
this.OnPropertyChanged("SelectAll");
}
}
xml
<DataGridTemplateColumn>
<DataGridTemplateColumn.Header>
<CheckBox isChecked="{Binding SelectAll}"></CheckBox>
</DataGridTemplateColumn.Header>
<DataGridTemplateColumn.CellTemplate >
<DataTemplate >
<CheckBox IsChecked="{Binding MyRowCheckProperty}"></CheckBox>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
我不知道 xaml 绑定是否正确,但我希望你能看到我的意图
事实证明,要做到这一点比人们希望的要困难得多。
第一个问题是你不能仅仅将视图模型绑定到列标题,因为它没有视图模型作为它的数据上下文,所以你需要一个绑定代理来正确地将绑定路由到视图模型。
public class BindingProxy : Freezable
{
public static readonly DependencyProperty DataProperty = DependencyProperty.Register(
"Data",
typeof(object),
typeof(BindingProxy),
new UIPropertyMetadata(null));
public object Data
{
get { return this.GetValue(DataProperty); }
set { this.SetValue(DataProperty, value); }
}
protected override Freezable CreateInstanceCore()
{
return new BindingProxy();
}
}
现在在数据网格的资源中创建一个绑定代理:
<DataGrid.Resources>
<aon:BindingProxy
x:Key="DataContextProxy"
Data="{Binding}" />
</DataGrid.Resources>
然后需要将列定义为:
<DataGridTemplateColumn>
<DataGridTemplateColumn.HeaderTemplate>
<DataTemplate>
<CheckBox
Command="{Binding
Data.SelectAllCommand,
Source={StaticResource DataContextProxy}}"
IsChecked="{Binding
Data.AreAllSelected,
Mode=OneWay,
Source={StaticResource DataContextProxy},
UpdateSourceTrigger=PropertyChanged}"
IsThreeState="True" />
</DataTemplate>
</DataGridTemplateColumn.HeaderTemplate>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<CheckBox
IsChecked="{Binding
Path=IsSelected,
UpdateSourceTrigger=PropertyChanged}" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
请注意,需要绑定到复选框的IsChecked
依赖项属性及其Command
属性,并且IsChecked
绑定是OneWay
。 IsChecked
绑定获取复选框以显示项目的当前状态,而Command
绑定执行批量选择。 你需要两者。
现在在视图模型中:
public bool? AreAllSelected
{
get
{
return this.Items.All(candidate => candidate.IsSelected)
? true
: this.Items.All(candidate => !candidate.IsSelected)
? (bool?)false
: null;
}
set
{
if (value != null)
{
foreach (var item in this.Items)
{
item.IsSelected = value.Value;
}
}
this.RaisePropertyChanged();
}
}
SelectAllCommand
属性是ICommand
一个实现,其中Execute
方法是:
public void Execute(object parameter)
{
var allSelected = this.AreAllSelected;
switch (allSelected)
{
case true:
this.AreAllSelected = false;
break;
case false:
case null:
this.AreAllSelected = true;
break;
}
}
最后,每次IsSelected
的值更改时,您的行项目视图模型(即Items
)需要在主视图模型上引发PropertyChanged
。 你如何做到这一点完全取决于你。
Xaml文件
<DataGrid Grid.Row="1" AutoGenerateColumns="False" ColumnWidth="auto" ItemsSource="{Binding DataPoints}">
<DataGrid.Columns>
<DataGridCheckBoxColumn Binding="{Binding IsEnable, UpdateSourceTrigger=PropertyChanged}">
<DataGridCheckBoxColumn.Header>
<StackPanel Orientation="Horizontal">
<TextBlock Margin="2">启用</TextBlock>
<CheckBox IsChecked="{Binding Data.SelectAll,Source={StaticResource EquipmentPointConfigBindingProxy}}" />
</StackPanel>
</DataGridCheckBoxColumn.Header>
</DataGridCheckBoxColumn>
</DataGrid.Columns>
</DataGrid>
.cs文件
public class BindingProxy : Freezable
{
#region Overrides of Freezable
protected override Freezable CreateInstanceCore()
{
return new BindingProxy();
}
#endregion
public object Data
{
get { return (object)GetValue(DataProperty); }
set { SetValue(DataProperty, value); }
}
// Using a DependencyProperty as the backing store for Data. This enables animation, styling, binding, etc...
public static readonly DependencyProperty DataProperty =
DependencyProperty.Register("Data", typeof(object), typeof(BindingProxy), new UIPropertyMetadata(null));
}
.cs业务
public ObservableCollection<EquipmentDataPointViewModel> DataPoints { get; set; }
private bool selectAll;
public bool SelectAll
{
get { return selectAll; }
set
{
selectAll = value;
foreach (var item in DataPoints)
{
item.IsEnable = value;
}
this.RaisePropertyChanged("SelectAll");
}
}
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