c# - WPF 内存泄漏

Question

我有一个简单的 wpf 应用程序。在主窗口中，我有堆栈面板和 2 个按钮。第一个按钮添加了 100 个我的用户控件(没有任何数据绑定(bind)、事件、位图)，第二个按钮从面板中删除所有这些控件并调用 GC.Collect()。并且存在一些问题:1.在我第一次点击“删除”按钮后，我的内存并没有全部释放，我必须点击几次才能释放更多的内存。2. 5 - 10 分钟后内存释放但几兆字节不释放。

例如，在我的应用启动后，它需要 ~22mb当我添加 500 个控件时 - ~60mb在我第一次点击“删除”按钮后 - ~55mb(我等了一段时间，内存没有被释放)我点击了几次，内存下降到 25mb，我不明白这一点，我是 WPF 的新手，也许我错过了一些东西我想立即释放内存。

<Window x:Class="WpfApplication10.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="385" Width="553">
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="25" />
        <RowDefinition Height="240*" />
        <RowDefinition Height="25" />
    </Grid.RowDefinitions>
    <Grid 
            Name="border1" 
            Grid.Row="1"
            HorizontalAlignment="Stretch"
            VerticalAlignment="Stretch" >
        <ScrollViewer VerticalAlignment="Stretch"
                      Name="scrollViewer1" 
                      HorizontalAlignment="Stretch">
            <StackPanel 
                Margin="3,3,3,3"
                Background="Transparent"
                VerticalAlignment="Stretch"
                Name="activityStackPanel"
                HorizontalAlignment="Stretch">
            </StackPanel>
        </ScrollViewer>
    </Grid>
    <Button Content="Button" Grid.Row="2" Height="23" HorizontalAlignment="Left" Margin="12,0,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="button1_Click" />
    <Button Content="Button" Grid.Row="2" Height="23" HorizontalAlignment="Left" Margin="141,0,0,0" Name="button2" VerticalAlignment="Top" Width="75" Click="button2_Click" />
    <Label Content="Label" Grid.RowSpan="2" Height="28" HorizontalAlignment="Left" Margin="34,0,0,0" Name="label1" VerticalAlignment="Top" />
</Grid>

namespace WpfApplication10
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, RoutedEventArgs e)
        {
            int N = 100;
            //var r = new ActivityStatisticItem("111", "222", DateTime.Now, "333", 1);
            for (int i = 0; i < N; i++)
            {
                activityStackPanel.Children.Add(new UserControl1());
            }

            label1.Content = activityStackPanel.Children.Count;
        }

        private void button2_Click(object sender, RoutedEventArgs e)
        {
           activityStackPanel.Children.Clear();

            label1.Content = activityStackPanel.Children.Count;

            GC.Collect();
            GC.WaitForPendingFinalizers();
            GC.Collect();
        }
    }
}
<UserControl x:Class="WpfApplication10.UserControl1"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         Background="Transparent"
         Margin="0,2,0,2"
         MinHeight="80"
         MinWidth="130"
         MaxHeight="80">
<Grid Width="441">
    <Grid.RowDefinitions>
        <RowDefinition Height="40" Name="rowTop" />
        <RowDefinition Height="40" Name="rowBottom"/>
    </Grid.RowDefinitions>
    <Border BorderBrush="Gray" 
            BorderThickness="1" 
            HorizontalAlignment="Stretch" 
            Background="LightGreen"
            Name="contactPanel" 
            CornerRadius="3,3,3,3"
            VerticalAlignment="Stretch" Panel.ZIndex="1" >
        <Grid
            VerticalAlignment="Stretch" 
            Name="grid1" 
            Margin="3,0,3,0"
            HorizontalAlignment="Stretch">

            <Label Content="Contact" Height="15" HorizontalAlignment="Left" Margin="15,3,0,0" Name="headerLabel" Padding="0" VerticalAlignment="Top" FontSize="10" FontWeight="DemiBold"/>
            <Label Content="00/00/0000 00:00:00" Height="15" HorizontalAlignment="Left" Margin="13,18,0,0" Name="timeLabel" Padding="0" VerticalAlignment="Top" FontSize="10" Width="100" FontWeight="DemiBold" />
            <Label Content="00:00:00" Height="15" HorizontalAlignment="Right" Margin="0,18,0,0" Name="durationLabel" Padding="0" VerticalAlignment="Top" FontSize="10" Width="38" FontWeight="DemiBold"/>

            <!--<Image Height="12" HorizontalAlignment="Left" Margin="0,3,0,0" Name="directionPictureBox" Stretch="Fill" VerticalAlignment="Top" Width="12"  />
            <Image Height="12" HorizontalAlignment="Right" Margin="0,20,41,0" Name="timerImage" Stretch="Fill" VerticalAlignment="Top" Width="12"          />
            <Image Height="12" HorizontalAlignment="Left" Margin="0,20,0,0" Name="dateTimeImage" Stretch="Fill" VerticalAlignment="Top" Width="12"       />-->


        </Grid>
    </Border>
    <Border BorderBrush="Gray" 
            BorderThickness="1,0,1,1" 
            Grid.Row="1" 
            Background="White"
            HorizontalAlignment="Stretch" 
            Margin="10,0,10,0" 
            Name="detailsPanel" 
            CornerRadius="0,0,3,3"
            VerticalAlignment="Stretch">
        <Grid HorizontalAlignment="Stretch" 
              Name="grid2" 
              Margin="3,0,3,0"
              VerticalAlignment="Stretch">
            <Label Content="Label" Height="15" HorizontalAlignment="Stretch" FontSize="9" Padding="0" Margin="0,3,0,0" Name="numberRadLabel" VerticalAlignment="Top" />
            <Label Content="Label" Height="15" HorizontalAlignment="Stretch" FontSize="9"  Padding="0" Margin="0,18,0,0" Name="queueRadLabel" VerticalAlignment="Top" />

        </Grid>
    </Border>
</Grid>

在用户控制中我只有

         public UserControl1()
         {
            InitializeComponent();
         }

Answer 1

I want to release memory immediately.

不要。信任 GC。

GC.Collect();
GC.WaitForPendingFinalizers();
GC.Collect();

不要。信任 GC。

After 5 - 10 min memory releases

我不是说信任 GC 吗？

---

• 垃圾收集模型将确保释放系统中不需要的托管内存(其中包括几乎所有控件内存)。它使用一种优化算法，包括代数、可用内存、可能的 CPU 可用......所以 GC.Collect() 会干扰它。

• GC.Collect() 是异步的，因此不会立即生效。

• 您需要注意的唯一资源是通常由 Dispose Pattern 处理的非托管资源。否则不要乱用 GC，它的工作做得很好。