我正在尝试选择DataGrid中的所有CheckBox,但是使用下面的代码没有得到任何结果
这是单击主CheckBox时我要调用的函数
private void CheckUnCheckAll(object sender, RoutedEventArgs e)
{
CheckBox chkSelectAll = ((CheckBox)sender);
if (chkSelectAll.IsChecked == true)
{
dgUsers.Items.OfType<CheckBox>().ToList().ForEach(x => x.IsChecked = true);
}
else
{
dgUsers.Items.OfType<CheckBox>().ToList().ForEach(x => x.IsChecked = false);
}
}
dgUsers是DataGrid,但据我所知,任何复选框都会被找到。
这是我用来在数据网格中创建CheckBox的XAML
<DataGrid.Columns>
<DataGridCheckBoxColumn x:Name="col0" HeaderStyle="{StaticResource ColumnHeaderGripperStyle}">
<DataGridCheckBoxColumn.HeaderTemplate>
<DataTemplate>
<CheckBox Click="CheckUnCheckAll" >
</CheckBox>
</DataTemplate>
</DataGridCheckBoxColumn.HeaderTemplate>
</DataGridCheckBoxColumn>
<DataGrid.Columns>
这是我的DataGrid的照片
有没有办法以编程方式选中所有复选框?
编辑我已经尝试关注this steps了
你可以看到我的代码在那里是一样的,但是对我不起作用
发布于 2018-02-26 21:52:33
TLDR;这就是你想要的,代码如下:
执行此操作的适当位置应该在ViewModel中。您的CheckBox可以有三种状态,您希望使用所有这些状态:
选中项目-每个项目都是checked
您可能希望在选中/取消选中某个项目时更新CheckBox,并在更改CheckBox时更新所有项目-仅以一种方式实现此操作将使CheckBox处于无效状态,这可能会对用户体验产生负面影响。我的建议是:一路走下去,正确地实现它。要做到这一点,您需要知道是哪个引起了更改-条目的CheckBox还是头中的CheckBox。
下面是我会怎么做:
首先,您需要为您的项目提供一个ViewModel,我在这里使用了一个非常简单的只包含IsChecked
属性的the。
public class Entry : INotifyPropertyChanged
{
private bool _isChecked;
public bool IsChecked
{
get => _isChecked;
set
{
if (value == _isChecked) return;
_isChecked = value;
OnPropertyChanged();
}
}
public event PropertyChangedEventHandler PropertyChanged;
[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
您的主ViewModel将拥有一个包含所有项的集合。每当项的IsChecked
属性更改时,您必须检查是否选中/取消选中所有项,并更新标题中的CheckBox (或者更确切地说,更新其数据源的值)。
public class ViewModel : INotifyPropertyChanged
{
public List<Entry> Entries
{
get => _entries;
set
{
if (Equals(value, _entries)) return;
_entries = value;
OnPropertyChanged();
}
}
public ViewModel()
{
// Just some demo data
Entries = new List<Entry>
{
new Entry(),
new Entry(),
new Entry(),
new Entry()
};
// Make sure to listen to changes.
// If you add/remove items, don't forgat to add/remove the event handlers too
foreach (Entry entry in Entries)
{
entry.PropertyChanged += EntryOnPropertyChanged;
}
}
private void EntryOnPropertyChanged(object sender, PropertyChangedEventArgs args)
{
// Only re-check if the IsChecked property changed
if(args.PropertyName == nameof(Entry.IsChecked))
RecheckAllSelected();
}
private void AllSelectedChanged()
{
// Has this change been caused by some other change?
// return so we don't mess things up
if (_allSelectedChanging) return;
try
{
_allSelectedChanging = true;
// this can of course be simplified
if (AllSelected == true)
{
foreach (Entry kommune in Entries)
kommune.IsChecked = true;
}
else if (AllSelected == false)
{
foreach (Entry kommune in Entries)
kommune.IsChecked = false;
}
}
finally
{
_allSelectedChanging = false;
}
}
private void RecheckAllSelected()
{
// Has this change been caused by some other change?
// return so we don't mess things up
if (_allSelectedChanging) return;
try
{
_allSelectedChanging = true;
if (Entries.All(e => e.IsChecked))
AllSelected = true;
else if (Entries.All(e => !e.IsChecked))
AllSelected = false;
else
AllSelected = null;
}
finally
{
_allSelectedChanging = false;
}
}
public bool? AllSelected
{
get => _allSelected;
set
{
if (value == _allSelected) return;
_allSelected = value;
// Set all other CheckBoxes
AllSelectedChanged();
OnPropertyChanged();
}
}
private bool _allSelectedChanging;
private List<Entry> _entries;
private bool? _allSelected;
public event PropertyChangedEventHandler PropertyChanged;
[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
演示XAML:
<DataGrid ItemsSource="{Binding Entries}" AutoGenerateColumns="False" IsReadOnly="False" CanUserAddRows="False">
<DataGrid.Columns>
<DataGridCheckBoxColumn Binding="{Binding IsChecked, UpdateSourceTrigger=PropertyChanged}">
<DataGridCheckBoxColumn.HeaderTemplate>
<DataTemplate>
<CheckBox IsChecked="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=local:MainWindow}, Path=ViewModel.AllSelected}">Select All</CheckBox>
</DataTemplate>
</DataGridCheckBoxColumn.HeaderTemplate>
</DataGridCheckBoxColumn>
</DataGrid.Columns>
</DataGrid>
发布于 2018-02-26 21:28:10
您在示例中所做的是遍历数据项,而不是遍历控件(我假设您没有作为ItemsSource的控件)。
在您发布的链接中,YourClass
是来自ViewModel的类,即网格行的数据对象。
这种方法只需对您的CommandParameter
):进行最少的代码更改即可工作(但我更喜欢在ViewModel中使用类似于将 IsChecked
绑定到 CheckUncheckCommand的CheckUncheckCommand+绑定的方式来处理它
<DataGridCheckBoxColumn x:Name="col0" HeaderStyle="{StaticResource ColumnHeaderGripperStyle}" DisplayIndex="0">
private void CheckUnCheckAll(object sender, RoutedEventArgs e)
{
var chkSelectAll = sender as CheckBox;
var firstCol = dgUsers.Columns.OfType<DataGridCheckBoxColumn>().FirstOrDefault(c => c.DisplayIndex == 0);
if (chkSelectAll == null || firstCol == null || dgUsers?.Items == null)
{
return;
}
foreach (var item in dgUsers.Items)
{
var chBx = firstCol.GetCellContent(item) as CheckBox;
if (chBx == null)
{
continue;
}
chBx.IsChecked = chkSelectAll.IsChecked;
}
}
发布于 2019-05-23 23:54:32
这是基于@Manfred的solution的修改。我使用Command
而不是event
。
XAML:
<DataGrid ItemsSource="{Binding Students}" AutoGenerateColumns="True" CanUserAddRows="False">
<DataGrid.Columns>
<DataGridTemplateColumn>
<DataGridTemplateColumn.HeaderTemplate>
<DataTemplate>
<CheckBox IsChecked="{Binding DataContext.IsAllSelected, RelativeSource={RelativeSource AncestorType=DataGrid}}" Command="{Binding DataContext.CheckAllStudentsCommand, RelativeSource={RelativeSource AncestorType=DataGrid}}" />
</DataTemplate>
</DataGridTemplateColumn.HeaderTemplate>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<CheckBox IsChecked="{Binding IsChecked, UpdateSourceTrigger=PropertyChanged}" Command="{Binding DataContext.CheckStudentCommand, RelativeSource={RelativeSource AncestorType=DataGrid}}" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
ViewModel:
public class MainWindowViewModel : INotifyPropertyChanged
{
private List<Student> students;
public List<Student> Students
{
get { return students; }
set { students = value; OnPropertyChanged(); }
}
private bool? isAllSelected;
public bool? IsAllSelected
{
get { return isAllSelected; }
set { isAllSelected = value; OnPropertyChanged(); }
}
public RelayCommand CheckStudentCommand { get; private set; }
public RelayCommand CheckAllStudentsCommand { get; private set; }
public MainWindowViewModel()
{
Students = new List<Student>() { new Student { Name = "Walter" }, new Student { Name = "Jenny" }, new Student { Name = "Joe" } };
CheckStudentCommand = new RelayCommand(OnCheckStudent);
CheckAllStudentsCommand = new RelayCommand(OnCheckAllStudents);
IsAllSelected = false;
}
private void OnCheckAllStudents()
{
if (IsAllSelected == true)
Students.ForEach(x => x.IsChecked = true);
else
Students.ForEach(x => x.IsChecked = false);
}
private void OnCheckStudent()
{
if (Students.All(x => x.IsChecked))
IsAllSelected = true;
else if (Students.All(x => !x.IsChecked))
IsAllSelected = false;
else
IsAllSelected = null;
}
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
源代码可在here上找到
https://stackoverflow.com/questions/48955781
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