我怎样才能动态改变在WPF约束力DataGridTextColumn转换器? [英] How can I dynamically change the converter on DataGridTextColumn binding in WPF?
问题描述
我真的不明白WPF和XAML,并继承了一些可怕的书面code,所以我可能会屠宰这一点,但在这里不用。
I really don't understand WPF and XAML, and inherited some terribly written code, so I may be butchering this, but here goes.
我继承的约束(在code后面)一个DataGrid,以Person对象,在必要的DataGridTextColumns在XAML指定的列表(presumably让造型)。
I inherited a DataGrid bound (in code behind) to a list of Person objects, where the necessary DataGridTextColumns are specified in XAML (presumably to allow styling).
<DataGrid x:Name="PersonGrid" ItemsSource="{Binding}" AutoGenerateColumns="False">
<DataGrid.Columns>
<DataGridTextColumn Binding="{Binding Path=LastName}" MaxWidth="Infinity" MinWidth="150" Header="Last Name">
<DataGridTextColumn Binding="{Binding Path=FirstName}" MaxWidth="Infinity" MinWidth="150" Header="First Name" />
<DataGridTextColumn Binding="{Binding Path=DOB, StringFormat=\{0:MM/dd/yyyy\}}" MaxWidth="Infinity" MinWidth="200" Header="Date of Birth (MM/DD/YYYY)" />
<DataGridTextColumn Binding="{Binding Path=Number}" MaxWidth="Infinity" MinWidth="150" Header="(P)erson Number" />
</DataGrid.Columns>
<DataGrid.DataContext>
<dm:Person />
</DataGrid.DataContext>
</DataGrid>
我想只显示该人最后初期,可选基于一个复选框的状态。
I would like to display just the person's last initial, optionally based on the state of a checkbox.
<CheckBox Name="ShowFullNames_CheckBox" Content="Show Full Names" IsChecked="False"/>
我能够连接一台变频器的姓氏在code绑定的背后,却得到一个错误(绑定它已被用于后不能更改。)当我尝试改变数据后转换器势必。
I was able to hook up a converter to the LastName Binding in code behind, but get an error ("Binding cannot be changed after it has been used.") when I try to change that converter after the data is bound.
我想,也许我也可以绑定的复选框状态器isChecked向ConverterParameter或一个Multibinding结合,但不能得到工作。
I thought that maybe I could also bind the checkbox IsChecked state to the ConverterParameter or one binding of a Multibinding, but couldn't get that to work.
<DataGridTextColumn MaxWidth="Infinity" MinWidth="150" Header="Last Name">
<DataGridTextColumn.Binding>
<MultiBinding Converter="myStringTruncator">
<Binding Source="ShowFullNames_CheckBox" Path="IsChecked"/>
<Binding Path="LastName"/>
</MultiBinding>
</DataGridTextColumn.Binding>
</DataGridTextColumn>
在myStringTruncator的转换方法,第一个结合只是充满了DependencyProperty.UnsetValue,而不是复选框的值。
In the Convert method of myStringTruncator, the first binding was just filled with DependencyProperty.UnsetValue, instead of the value of the checkbox.
有可能是一个非常简单的方法来做到这一点,我没有看到。任何想法?
There's probably a really simple way to do this that I'm not seeing. Any ideas?
推荐答案
您可以转换器添加到XAML绑定。
You can add the Converter to the Binding in XAML.
<DataGridTextColumn Binding="{Binding Path=LastName, Converter={StaticResource YourConverter}"
MaxWidth="Infinity"
MinWidth="150"
Header="Last Name">
但对于绑定复选框的状态,你将不得不使用这样的事情(未经测试)
But for binding the state of the checkbox you would have to use something like this (untested)
<DataGridTextColumn Header="Last Name">
<DataGridTextColumn.Binding>
<MultiBinding Converter="{StaticResource NameAndCheckBoxMultiValueConverter}">
<Binding Path="LastName" />
<Binding ElementName="myCheckBox" Path="IsChecked" />
</MultiBinding>
</DataGridTextColumn.Binding>
</DataGridTextColumn>
和转换器:
using System;
using System.Globalization;
using System.Windows.Data;
namespace TestWpf
{
public class NameAndCheckBoxMultiValueConverter: IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
var lastName = values[0] as String;
if(lastName != null)
{
var isChecked = (bool)values[1];
if (isChecked)
{
return lastName.Substring(0,1);
}
return lastName;
}
return null;
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotImplementedException();
}
}
}
这篇关于我怎样才能动态改变在WPF约束力DataGridTextColumn转换器?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!