是否可以在 mvvm 模式中获取 wpf 数据网格上的动态列? [英] Is it possible to get dynamic columns on wpf datagrid in mvvm pattern?
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问题描述
我正在 wpf 中开发产品(使用 MVVM 模式).根据用户的自定义(用户将选择列)，我必须将一组数据显示到数据网格中.目前，我正在将具有一组属性的 ObservableCollection 绑定到数据网格的 ItemSource.这将我限制为固定的列大小.
I'm developing a product in wpf (using the MVVM pattern). According to the user's customization (user ll select the columns) I have to display a set of data into a datagrid. Currently I'm binding an ObservableCollection with set of properties to the ItemSource of the datagrid. This limits me to fixed column size.
注:列名列n列供用户选择.
Note: The n number of columns name is listed out for user's selection.
如果它在后面的代码中完成，datagrid.columns.add()"很容易.在这种情况下，任何人都可以帮助我.
If its done in code behind it is easy by "datagrid.columns.add()". Can any one out there help me in this scenario.
我的 xaml:
<my:DataGrid
AutoGenerateColumns="False"
Margin="357,121.723,82,41"
Name="dataGrid3"
c:DataGridExtension.Columns="{Binding ColumnCollection}"
/>
我的命令类:
public static class DataGridExtension
{
public static ObservableCollection<DataGridColumn> GetColumns(DependencyObject obj)
{
return (ObservableCollection<DataGridColumn>)obj.GetValue(ColumnsProperty);
}
public static void SetColumns(
DependencyObject obj, ObservableCollection<DataGridColumn> value)
{
obj.SetValue(ColumnsProperty, value);
}
public static readonly DependencyProperty ColumnsProperty =
DependencyProperty.RegisterAttached(
"Columns",
typeof(ObservableCollection<DataGridColumn>),typeof(DataGridExtension),
new UIPropertyMetadata(new ObservableCollection<DataGridColumn>(),
OnDataGridColumnsPropertyChanged));
private static void OnDataGridColumnsPropertyChanged(DependencyObject d,
DependencyPropertyChangedEventArgs e)
{
if (d.GetType() == typeof(DataGrid))
{
DataGrid myGrid = d as DataGrid;
var Columns = (ObservableCollection<DataGridColumn>)e.NewValue;
if (Columns != null)
{
myGrid.Columns.Clear();
if (Columns != null && Columns.Count > 0)
{
foreach (DataGridColumn dataGridColumn in Columns)
{
myGrid.Columns.Add(dataGridColumn);
}
}
Columns.CollectionChanged +=
(object sender, NotifyCollectionChangedEventArgs args)
{
if (args.NewItems != null)
{
//foreach (DataGridColumn column in args.NewItems.Cast<DataGridColumn>())
// myGrid.Columns.Add(column);
}
if (args.OldItems != null)
{
//foreach (DataGridColumn column in args.OldItems.Cast<DataGridColumn>())
// myGrid.Columns.Remove(column);
}
};
}
}
}
}
和我在视图模型中的属性:
and my property in viewmodel:
private ObservableCollection<DataGridColumn> _columnCollection =
new ObservableCollection<DataGridColumn>();
public ObservableCollection<DataGridColumn> ColumnCollection
{
get
{
return this._columnCollection;
}
set
{
_columnCollection = value;
base.OnPropertyChanged("ColumnCollection");
//Error
//base.OnPropertyChanged<ObservableCollection<DataGridColumn>>(
// () => this.ColumnCollection);
}
}
推荐答案
感谢您的努力……终于我找到了解决方案……
Thanks for your effort guy's... finally i have found the solution....
这里是..(full wpf mvvm)
here its..(full wpf mvvm)
在我的命令文件中:
public class DataGridColumnsBehavior
{
public static readonly DependencyProperty BindableColumnsProperty =
DependencyProperty.RegisterAttached("BindableColumns",
typeof(ObservableCollection<DataGridColumn>),
typeof(DataGridColumnsBehavior),
new UIPropertyMetadata(null, BindableColumnsPropertyChanged));
private static void BindableColumnsPropertyChanged(DependencyObject source, DependencyPropertyChangedEventArgs e)
{
DataGrid dataGrid = source as DataGrid;
ObservableCollection<DataGridColumn> columns = e.NewValue as ObservableCollection<DataGridColumn>;
dataGrid.Columns.Clear();
if (columns == null)
{
return;
}
foreach (DataGridColumn column in columns)
{
dataGrid.Columns.Add(column);
}
columns.CollectionChanged += (sender, e2) =>
{
NotifyCollectionChangedEventArgs ne = e2 as NotifyCollectionChangedEventArgs;
if (ne.Action == NotifyCollectionChangedAction.Reset)
{
dataGrid.Columns.Clear();
if (ne.NewItems != null)
{
foreach (DataGridColumn column in ne.NewItems)
{
dataGrid.Columns.Add(column);
}
}
}
else if (ne.Action == NotifyCollectionChangedAction.Add)
{
if (ne.NewItems != null)
{
foreach (DataGridColumn column in ne.NewItems)
{
dataGrid.Columns.Add(column);
}
}
}
else if (ne.Action == NotifyCollectionChangedAction.Move)
{
dataGrid.Columns.Move(ne.OldStartingIndex, ne.NewStartingIndex);
}
else if (ne.Action == NotifyCollectionChangedAction.Remove)
{
if (ne.OldItems != null)
{
foreach (DataGridColumn column in ne.OldItems)
{
dataGrid.Columns.Remove(column);
}
}
}
else if (ne.Action == NotifyCollectionChangedAction.Replace)
{
dataGrid.Columns[ne.NewStartingIndex] = ne.NewItems[0] as DataGridColumn;
}
};
}
public static void SetBindableColumns(DependencyObject element, ObservableCollection<DataGridColumn> value)
{
element.SetValue(BindableColumnsProperty, value);
}
public static ObservableCollection<DataGridColumn> GetBindableColumns(DependencyObject element)
{
return (ObservableCollection<DataGridColumn>)element.GetValue(BindableColumnsProperty);
}
}
在我的 xaml 中:
in my xaml:
<my:DataGrid AutoGenerateColumns="False" Margin="357,121.723,82,41" Name="dataGrid3" ItemsSource="{Binding Path=Datatable}" c:DataGridColumnsBehavior.BindableColumns="{Binding ColumnCollection}" />
最后在我的视图模型中:
and finaly in my viewmodel:
private ObservableCollection<DataGridColumn> _columnCollection = new ObservableCollection<DataGridColumn>();
public ObservableCollection<DataGridColumn> ColumnCollection
{
get
{
return this._columnCollection;
}
set
{
_columnCollection = value;
base.OnPropertyChanged("ColumnCollection");
//Error
//base.OnPropertyChanged<ObservableCollection<DataGridColumn>>(() => this.ColumnCollection);
}
}
private DataTable _datatable = new DataTable();
public DataTable Datatable
{
get
{
return _datatable;
}
set
{
if (_datatable != value)
{
_datatable = value;
}
base.OnPropertyChanged("Datatable");
}
}
在我的构造函数中:
public MainViewModel()
{
Datatable.Columns.Add("Name",typeof(string));
Datatable.Columns.Add("Color", typeof(string));
Datatable.Columns.Add("Phone", typeof(string));
Datatable.Rows.Add("Vinoth", "#00FF00", "456345654");
Datatable.Rows.Add("lkjasdgl", "Blue", "45654");
Datatable.Rows.Add("Vinoth", "#FF0000", "456456");
System.Windows.Data.Binding bindings = new System.Windows.Data.Binding("Name");
System.Windows.Data.Binding bindings1 = new System.Windows.Data.Binding("Phone");
System.Windows.Data.Binding bindings2 = new System.Windows.Data.Binding("Color");
DataGridTextColumn s = new DataGridTextColumn();
s.Header = "Name";
s.Binding = bindings;
DataGridTextColumn s1 = new DataGridTextColumn();
s1.Header = "Phone";
s1.Binding = bindings1;
DataGridTextColumn s2 = new DataGridTextColumn();
s2.Header = "Color";
s2.Binding = bindings2;
FrameworkElementFactory textblock = new FrameworkElementFactory(typeof(TextBlock));
textblock.Name = "text";
System.Windows.Data.Binding prodID = new System.Windows.Data.Binding("Name");
System.Windows.Data.Binding color = new System.Windows.Data.Binding("Color");
textblock.SetBinding(TextBlock.TextProperty, prodID);
textblock.SetValue(TextBlock.TextWrappingProperty, TextWrapping.Wrap);
//textblock.SetValue(TextBlock.BackgroundProperty, color);
textblock.SetValue(TextBlock.NameProperty, "textblock");
//FrameworkElementFactory border = new FrameworkElementFactory(typeof(Border));
//border.SetValue(Border.NameProperty, "border");
//border.AppendChild(textblock);
DataTrigger t = new DataTrigger();
t.Binding = new System.Windows.Data.Binding { Path = new PropertyPath("Name"), Converter = new EnableConverter(), ConverterParameter ="Phone" };
t.Value = 1;
t.Setters.Add(new Setter(TextBlock.BackgroundProperty, Brushes.LightGreen, textblock.Name));
t.Setters.Add(new Setter(TextBlock.ToolTipProperty, bindings, textblock.Name));
DataTrigger t1 = new DataTrigger();
t1.Binding = new System.Windows.Data.Binding { Path = new PropertyPath("Name"), Converter = new EnableConverter(), ConverterParameter = "Phone" };
t1.Value = 2;
t1.Setters.Add(new Setter(TextBlock.BackgroundProperty, Brushes.LightYellow, textblock.Name));
t1.Setters.Add(new Setter(TextBlock.ToolTipProperty, bindings, textblock.Name));
DataTemplate d = new DataTemplate();
d.VisualTree = textblock;
d.Triggers.Add(t);
d.Triggers.Add(t1);
DataGridTemplateColumn s3 = new DataGridTemplateColumn();
s3.Header = "Name 1";
s3.CellTemplate = d;
s3.Width = 140;
ColumnCollection.Add(s);
ColumnCollection.Add(s1);
ColumnCollection.Add(s2);
ColumnCollection.Add(s3);
}
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