WPF-在后面的代码中更改样式 [英] WPF - Change a style in code behind
问题描述
我有一个列表框，显示TFS查询的结果。我想在后面的代码中更改ListBoxItem的样式，以使查询结果中包含这些列。
I have a list box that displays the results of a TFS Query. I want to change the style of the ListBoxItem in the code behind to have the columns that are included in the query results.
ListBoxItem的样式在Windows中定义。重新分配部分。我已经尝试过：
The style for the ListBoxItem is defined in my Windows.Resoruces Section. I have tried this:
public T GetQueryResultsElement<T>(string name) where T : DependencyObject
{
ListBoxItem myListBoxItem =
(ListBoxItem)(lstQueryResults.ItemContainerGenerator.ContainerFromIndex(0));
// Getting the ContentPresenter of myListBoxItem
ContentPresenter myContentPresenter =
myListBoxItem.Template.LoadContent().FindVisualChild<ContentPresenter>();
// Finding textBlock from the DataTemplate that is set on that ContentPresenter
DataTemplate myDataTemplate = myContentPresenter.ContentTemplate; <------+
T myControl = (T)myDataTemplate.FindName(name, myContentPresenter); |
|
return (T)myControl; |
} |
|
ContentTemplate is null ----------------------------------------------+
但是ContentTemplate为null。我从此处那里获得了代码，然后通过 LoadContent 调用对其进行了修改（原始代码为ContentPresenter提供了空值）。
But the ContentTemplate is null. I got that code from here, then modified it with the LoadContent call (the orginal code gave null for the ContentPresenter).
任何方式。如果您知道在后面的代码中更改现有样式的方法，我将很乐意看到它。
Anyway. If you know a way to change an existing style in the code behind I would love to see it.
如果您要想要它们：
我打算以ListBoxItem样式使用WrapPanel。这就是我想向其中添加多余的TextBlock项的地方。
Specifics if you want them:
I am going for WrapPanel in my ListBoxItem Style. This is what I want to add the extra TextBlock items to.
这是我的风格的一部分：
Here is part of my style:
<!--Checkbox ListBox-->
<Style x:Key="CheckBoxListStyle" TargetType="ListBox">
<Style.Resources>
<Style x:Key="ListBoxItemStyle" TargetType="ListBoxItem">
<Setter Property="Tag" Value="{Binding Id}"/>
<Setter Property="Background">
<Setter.Value>
<Binding Path="Type" Converter="{StaticResource WorkItemTypeToColorConverter}" />
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListBoxItem">
<Border BorderThickness="1" BorderBrush="#D4D4FF">
<Grid Width="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type WrapPanel}}, Path=ActualWidth}" ScrollViewer.CanContentScroll="True" Margin="2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="20" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="30" />
</Grid.ColumnDefinitions>
<Grid.Background>
<Binding Path="Type" Converter="{StaticResource WorkItemTypeToColorConverter}" />
</Grid.Background>
<CheckBox VerticalAlignment="Center" Grid.Column="0" IsChecked="{Binding IsSelected,
RelativeSource={RelativeSource TemplatedParent},
Mode=TwoWay}" Name="chkIsSelected" />
<WrapPanel Grid.Column="1" Margin="5,0,5,0" Name="QueryColumns">
<TextBlock VerticalAlignment="Center" Text="{Binding Id}" Name="txtID" />
<TextBlock VerticalAlignment="Center" Margin="5,0,5,0" Text="{Binding Title}" Name="txtTitle" />
</WrapPanel>
推荐答案
您在这里遇到了麻烦，试图直接在后台代码中操作视觉元素。有一个非常简单的解决方案涉及数据绑定。
You're going against the grain here, trying to manipulate visual elements directly in code-behind. There's a much simple solution involving data binding.
我将提供常规解决方案，因为我不知道您的解决方案的具体细节。
I'll provide the general solution because I don't know the specifics of your solution.
获得查询结果后，创建一个枚举，该枚举返回每次迭代的列名和字段值。
Once you get your query results, create an enumeration that returns a column name, and a field value for each iteration.
示例：
class NameValuePair
{
public string Name { get; set; }
public object Value { get; set; }
}
public IEnumerable<IEnumerable<NameValuePair>> EnumerateResultSet(DataTable resultSet)
{
foreach (DataRow row in resultSet.Rows)
yield return EnumerateColumns(resultSet, row);
}
public IEnumerable<NameValuePair> EnumerateColumns(DataTable resultSet, DataRow row)
{
foreach (DataColumn column in resultSet.Columns)
yield return new NameValuePair
{ Name = column.ColumnName, Value = row[column] };
}
在代码中，一旦获得DataTable结果集，
And in your code-behind, once you get your DataTable result set, do this:
myResultsList.ItemsSource = EnumerateResultSet(myDataTable);
XAML可能看起来像这样：
The XAML might look like this:
<Window.Resources>
<DataTemplate x:Key="ColumnTemplate">
<Border BorderBrush="Black" BorderThickness="1" CornerRadius="2" Padding="2">
<WrapPanel>
<TextBlock Text="{Binding Name}" Margin="0,0,5,0"/>
<TextBlock Text="{Binding Value}" Margin="0,0,10,0"/>
</WrapPanel>
</Border>
</DataTemplate>
<DataTemplate x:Key="RowTemplate">
<Grid>
<ItemsControl
ItemsSource="{Binding}"
ItemTemplate="{StaticResource ColumnTemplate}"
Margin="0,5,0,5"/>
</Grid>
</DataTemplate>
</Window.Resources>
<Grid>
<ListBox Name="myResultsList" ItemTemplate="{StaticResource RowTemplate}"/>
</Grid>
样本输出：
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