我已经在网上搜索了很多网站,但没有找到任何解决方案。声明是,UserControl 和 CustomControl 之间没有性能差异。
但我有以下测试类 X、UserControl、CustomControl 和 MainWindow:
public class X : INotifyPropertyChanged
{
private string _title;
public string Title
{
get
{
return _title;
}
set
{
if (value == _title)
{
return;
}
_title = value;
OnPropertyChanged("Title");
}
}
public event PropertyChangedEventHandler PropertyChanged;
[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
用户控制:
<UserControl x:Class="controlperformance.DisplayView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006">
<Grid Name="root" Background="LightGray">
<TextBlock Text="{Binding Title}" />
</Grid>
</UserControl>
自定义控件:
public class DisplayControl : Control
{
#region Title
public string Title
{
get
{
return (string)GetValue(TitleProperty);
}
set
{
SetValue(TitleProperty, value);
}
}
public static readonly DependencyProperty TitleProperty = DependencyProperty.Register("Title",
typeof(string),
typeof(DisplayControl),
new PropertyMetadata(default(string)));
#endregion
static DisplayControl()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(DisplayControl), new FrameworkPropertyMetadata(typeof(DisplayControl)));
}
}
xml:
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:DisplayControl}">
<Grid Background="white">
<TextBlock Text="{TemplateBinding Title}" />
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
主窗口:
public partial class MainWindow : Window
{
Stopwatch sw = new Stopwatch();
public MainWindow()
{
InitializeComponent();
Loaded += OnLoaded;
sw.Start();
ObservableCollection<X> list = new ObservableCollection<X>();
Random r = new Random();
for (int i = 0; i < 50000; i++)
{
list.Add(new X { Title = r.Next().ToString()});
}
itemscontrol.ItemsSource = list;
}
private void OnLoaded(object sender, RoutedEventArgs routedEventArgs)
{
sw.Stop();
MessageBox.Show(sw.Elapsed.ToString());
}
}
主窗口内容:
<ItemsControl Name="itemscontrol">
<ItemsControl.ItemTemplate>
<!--<DataTemplate DataType="{x:Type Controlperformance:X}">
<Controlperformance:DisplayView DataContext="{Binding}" />
</DataTemplate>-->
<DataTemplate DataType="{x:Type Controlperformance:X}">
<Controlperformance:DisplayControl Title="{Binding Title}"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
使用 CustomControl 时,MessageBox 显示大约。在我的电脑上是 20 秒,但是当使用 UserControl 时,大约需要一分钟!用它的 Grid 和 TextBox 替换控件,它甚至比 CustomControl 更快(约 16 秒)。
有人能看出瓶颈在哪里吗?这个问题出现在我的实际应用程序中,其中模板/控件会复杂得多。
非常感谢,
微