我的解决方案允许在
DataGridColumn
中写入单行,其中包含需要绑定的属性的名称。它具有以下功能:
- 支持
DataGridTextColumn
- 支持
DataGridTemplateColumn
- 为每个列设置
StringFormat
- 指定
StringFormat
的静态值
- 完全符合MVVM模式
下面是一个示例,其中包括
StringFormat
(他应该位于
PropertyPath
之前):
<DataGridTextColumn Behaviors:DataGridHeader.StringFormat="StringFormat: {0:C}"
Behaviors:DataGridHeader.PropertyPath="HeaderValueOne" ... />
等同于这一行:
<DataGridTextColumn HeaderStringFormat="{0:C}"
Header="{Binding Path=HeaderValueOne}" ... />
如果需要更多解决方案和功能示例,请查看以下内容。
链接
获取示例项目。
关于解决方案的说明
在我之前看到的所有解决方案中,最简单的一个是这个示例
:
<DataGridTextColumn Binding="{Binding Name}">
<DataGridTextColumn.HeaderTemplate>
<DataTemplate>
<TextBlock Text="{Binding Path=DataContext.YourPropertyName,
RelativeSource={RelativeSource AncestorType={x:Type SomeControl}}" />
</DataTemplate>
</DataGridTextColumn.HeaderTemplate>
</DataGridTextColumn>
请注意
DataGridTextColumn.HeaderTemplate
,如果使用
DataGridTextColumn.Header
,则对于.NET框架版本低于4.5和Silverlight会产生异常:
Header属性不支持UIElements
看起来需要什么呢?我想找到一个解决方案,可以在
DataGridColumn
中编写一个单行代码,用于绑定需要绑定的属性名称。
这里发生了什么:
<DataGridTextColumn Behaviors:DataGridHeader.PropertyPath="HeaderValueOne" // Attached dependency property
这个结构与这个类似:
<DataGridTextColumn Header="{Binding Path=HeaderValueOne}" ... />
还可以像这样为每列使用StringFormat
:
<DataGridTextColumn Behaviors:DataGridHeader.StringFormat="StringFormat: {0:C}"
Behaviors:DataGridHeader.PropertyPath="TestStringFormatValue" ... />
还有一种方法可以为StringFormat
指定静态值:
<DataGridTextColumn Behaviors:DataGridHeader.StringFormat="{x:Static Member=this:TestData.TestStaticStringFormatValue}"
Behaviors:DataGridHeader.PropertyPath="TestStringFormatValue"
这是原始的DataTemplate
,它动态地设置到列中:
<DataTemplate>
<TextBlock Text="{Binding Path=DataContext.YourPropertyName,
StringFormat="YourStringFormat",
RelativeSource={RelativeSource AncestorType={x:Type DataGridCellsPanel}}}" />
</DataTemplate>
为了使
RelativeSource
不依赖于
DataContext
的类型,我从Mr.
Bruno
那里得到了一个很好的
解决方案
。
在这种情况下,
DataGridCellsPanel
包含正确的
DataContext
,该
DataContext
是为父DataGrid设置的。
以下是执行所有操作的基本代码:
IsSetHeader PropertyChanged handler
private static void IsSetHeader(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
var textColumn = sender as DataGridTextColumn;
var templateColumn = sender as DataGridTemplateColumn;
string path = e.NewValue as string;
if ((textColumn == null) & (templateColumn == null))
{
return;
}
if (String.IsNullOrEmpty(path) == false)
{
currentStringFormat = ReturnStringFormat(textColumn, templateColumn);
dataTemplate = CreateDynamicDataTemplate(path, currentStringFormat);
if (dataTemplate != null)
{
if (textColumn != null)
textColumn.HeaderTemplate = dataTemplate;
if (templateColumn != null)
templateColumn.HeaderTemplate = dataTemplate;
}
}
}
CreateDynamicDataTemplate
private static DataTemplate CreateDynamicDataTemplate(string propertyPath, string stringFormat)
{
var pc = new ParserContext();
MemoryStream sr = null;
string xaml = GetXamlString(propertyPath, stringFormat);
sr = new MemoryStream(Encoding.ASCII.GetBytes(xaml));
pc.XmlnsDictionary.Add("", "http://schemas.microsoft.com/winfx/2006/xaml/presentation");
pc.XmlnsDictionary.Add("x", "http://schemas.microsoft.com/winfx/2006/xaml");
return XamlReader.Load(sr, pc) as DataTemplate;
}
GetXamlString
private static string GetXamlString(string propertyPath, string stringFormat)
}}"
#endregion
var sb = new StringBuilder();
sb.Append("<DataTemplate><TextBlock Text=\"}}\" /></DataTemplate>");
return sb.ToString();
}
StringFormat
必须出现在 PropertyPath 之前,因为它是可选的。为了避免出现未注册 StringFormat
的列导致异常,我在 GetStringFormat
中注册了 try-catch:
public static string GetStringFormat(DependencyObject DepObject)
{
try
{
return (string)DepObject.GetValue(StringFormatProperty);
}
catch
{
return String.Empty;
}
}
优点:不要在尝试获取值的方法的try-catch块中编写代码。
缺点:每个遗漏的StringFormat异常都会在程序启动时生成一次。如果这对您很重要,您可以始终为列指定StringFormat="null"
。
万一需要,展示项目完整代码:
public static class DataGridHeader
{
#region Private Section
private static string textColumnStringFormat = null;
private static string templateColumnStringFormat = null;
private static string currentStringFormat = null;
private static DataTemplate dataTemplate = null;
#endregion
#region PropertyPath DependencyProperty
public static readonly DependencyProperty PropertyPathProperty;
public static void SetPropertyPath(DependencyObject DepObject, string value)
{
DepObject.SetValue(PropertyPathProperty, value);
}
public static string GetPropertyPath(DependencyObject DepObject)
{
return (string)DepObject.GetValue(PropertyPathProperty);
}
#endregion
#region StringFormat DependencyProperty
public static readonly DependencyProperty StringFormatProperty;
public static void SetStringFormat(DependencyObject DepObject, string value)
{
DepObject.SetValue(StringFormatProperty, value);
}
public static string GetStringFormat(DependencyObject DepObject)
{
try
{
return (string)DepObject.GetValue(StringFormatProperty);
}
catch
{
return String.Empty;
}
}
#endregion
#region Constructor
static DataGridHeader()
{
PropertyPathProperty = DependencyProperty.RegisterAttached("PropertyPath",
typeof(string),
typeof(DataGridHeader),
new UIPropertyMetadata(String.Empty, IsSetHeader));
StringFormatProperty = DependencyProperty.RegisterAttached("StringFormat",
typeof(string),
typeof(DataGridHeader),
new UIPropertyMetadata(String.Empty));
}
#endregion
#region IsSetHeader PropertyChanged Handler
private static void IsSetHeader(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
var textColumn = sender as DataGridTextColumn;
var templateColumn = sender as DataGridTemplateColumn;
string path = e.NewValue as string;
if ((textColumn == null) & (templateColumn == null))
{
return;
}
if (String.IsNullOrEmpty(path) == false)
{
currentStringFormat = ReturnStringFormat(textColumn, templateColumn);
dataTemplate = CreateDynamicDataTemplate(path, currentStringFormat);
if (dataTemplate != null)
{
if (textColumn != null)
textColumn.HeaderTemplate = dataTemplate;
if (templateColumn != null)
templateColumn.HeaderTemplate = dataTemplate;
}
}
}
#endregion
#region ReturnStringFormat Helper
private static string ReturnStringFormat(DependencyObject depObject1, DependencyObject depObject2)
{
textColumnStringFormat = GetStringFormat(depObject1) as string;
templateColumnStringFormat = GetStringFormat(depObject2) as string;
if (String.IsNullOrEmpty(textColumnStringFormat) == false)
{
return textColumnStringFormat;
}
if (String.IsNullOrEmpty(templateColumnStringFormat) == false)
{
return templateColumnStringFormat;
}
return "null";
}
#endregion
#region CreateDynamicDataTemplate Helper
private static DataTemplate CreateDynamicDataTemplate(string propertyPath, string stringFormat)
{
var pc = new ParserContext();
MemoryStream sr = null;
string xaml = GetXamlString(propertyPath, stringFormat);
sr = new MemoryStream(Encoding.ASCII.GetBytes(xaml));
pc.XmlnsDictionary.Add("", "http://schemas.microsoft.com/winfx/2006/xaml/presentation");
pc.XmlnsDictionary.Add("x", "http://schemas.microsoft.com/winfx/2006/xaml");
return XamlReader.Load(sr, pc) as DataTemplate;
}
#endregion
#region GetXamlString Helper
private static string GetXamlString(string propertyPath, string stringFormat)
{
#region Original PropertyPath for TextBlock
#endregion
var sb = new StringBuilder();
sb.Append("<DataTemplate><TextBlock Text=\"{Binding Path=DataContext.");
sb.Append(propertyPath);
sb.Append(", StringFormat=");
sb.Append(stringFormat);
sb.Append(", RelativeSource={RelativeSource AncestorType={x:Type DataGridCellsPanel}}}\" /></DataTemplate>");
return sb.ToString();
}
#endregion
}
XAML
<Window x:Class="BindingHeaderInDataGrid.MainWindow"
xmlns="http:
xmlns:x="http:
xmlns:this="clr-namespace:BindingHeaderInDataGrid"
xmlns:Behaviors="clr-namespace:BindingHeaderInDataGrid.AttachedBehaviors"
WindowStartupLocation="CenterScreen"
Title="MainWindow" Height="220" Width="600">
<Window.DataContext>
<this:TestData />
</Window.DataContext>
<Grid Name="TestGrid">
<DataGrid Name="TestDataGrid"
Width="550"
Height="100"
Margin="10"
VerticalAlignment="Top"
Background="AliceBlue">
<DataGrid.Columns>
<DataGridTextColumn Behaviors:DataGridHeader.StringFormat="StringFormat: "
Behaviors:DataGridHeader.PropertyPath="TestStringFormatValue"
Width="100"
IsReadOnly="False">
<DataGridTextColumn.HeaderStyle>
<Style TargetType="">
<Setter Property="Height" Value="20" />
<Setter Property="Background" Value="Pink" />
<Setter Property="Margin" Value="2,0,0,0" />
</Style>
</DataGridTextColumn.HeaderStyle>
</DataGridTextColumn>
<DataGridTextColumn Behaviors:DataGridHeader.StringFormat=""
Behaviors:DataGridHeader.PropertyPath="TestStringFormatValue"
Width="2*"
IsReadOnly="False">
<DataGridTextColumn.HeaderStyle>
<Style TargetType="">
<Setter Property="Height" Value="20" />
<Setter Property="Background" Value="CadetBlue" />
<Setter Property="Margin" Value="2,0,0,0" />
</Style>
</DataGridTextColumn.HeaderStyle>
</DataGridTextColumn>
<DataGridTextColumn Behaviors:DataGridHeader.PropertyPath="TestUsualHeaderValue"
Width="1.5*"
IsReadOnly="False">
<DataGridTextColumn.HeaderStyle>
<Style TargetType="">
<Setter Property="Height" Value="20" />
<Setter Property="Background" Value="Gainsboro" />
<Setter Property="Margin" Value="2,0,0,0" />
</Style>
</DataGridTextColumn.HeaderStyle>
</DataGridTextColumn>
<DataGridTemplateColumn Behaviors:DataGridHeader.PropertyPath="TestTemplateColumnValue"
Width="150"
IsReadOnly="False">
<DataGridTemplateColumn.HeaderStyle>
<Style TargetType="">
<Setter Property="Height" Value="20" />
<Setter Property="Background" Value="Beige" />
<Setter Property="Margin" Value="2,0,0,0" />
</Style>
</DataGridTemplateColumn.HeaderStyle>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
<Button Name="ChangeHeader"
Width="100"
Height="30"
VerticalAlignment="Bottom"
Content="ChangeHeader"
Click="ChangeHeader_Click" />
</Grid>
</Window>
Code-behind
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
}
private void ChangeHeader_Click(object sender, RoutedEventArgs e)
{
TestData data = this.DataContext as TestData;
data.TestStringFormatValue = "777";
data.TestUsualHeaderValue = "DynamicUsualHeader";
data.TestTemplateColumnValue = "DynamicTemplateColumn";
}
}
public class TestData : NotificationObject
{
#region TestStringFormatValue
private string _testStringFormatValue = "1";
public string TestStringFormatValue
{
get
{
return _testStringFormatValue;
}
set
{
_testStringFormatValue = value;
NotifyPropertyChanged("TestStringFormatValue");
}
}
#endregion
#region TestStaticStringFormatValue
public static string TestStaticStringFormatValue = "Static StringFormat: {0}$";
#endregion
#region TestUsualHeaderValue
private string _testUsualHeaderValue = "UsualHeader";
public string TestUsualHeaderValue
{
get
{
return _testUsualHeaderValue;
}
set
{
_testUsualHeaderValue = value;
NotifyPropertyChanged("TestUsualHeaderValue");
}
}
#endregion
#region TestTemplateColumnValue
private string _testTemplateColumnValue = "TemplateColumn";
public string TestTemplateColumnValue
{
get
{
return _testTemplateColumnValue;
}
set
{
_testTemplateColumnValue = value;
NotifyPropertyChanged("TestTemplateColumnValue");
}
}
#endregion
}
behavior
关键字未被识别。您链接的博客文章根本没有提到它。我错过了什么?:( - Konrad Morawski<Page x:Class="MyClass" ... xmlns:behavior="clr-namespace:WpfApplication1.MyDataContextSpyNamespace">
- transistor1