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关于c＃：如何在更新单个ListViewItem的文本时防止ListView闪烁？

2023-04-16 20:42:00

How to prevent flickering in ListView when updating a single ListViewItem's text?

我想要的是更新ListViewItem的文本，而不会看到任何闪烁。

这是我的更新代码(多次调用)：

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listView.BeginUpdate();
listViewItem.SubItems[0].Text = state.ToString(); // update the state
listViewItem.SubItems[1].Text = progress.ToString(); // update the progress
listView.EndUpdate();

我已经看到了一些解决方案，其中涉及覆盖组件的WndProc():

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protected override void WndProc(ref Message m)
{
if (m.Msg == (int)WM.WM_ERASEBKGND)
{
m.Msg = (int)IntPtr.Zero;
}
base.WndProc(ref m);
}

他们说这解决了问题，但就我而言，没有。我相信这是因为我在每个项目上都使用了图标。

可接受的答案是可行的，但是相当冗长，并且仅出于启用双重缓冲而从控件派生(就像其他答案中提到的那样)也有点过头了。但是幸运的是，如果我们愿意，我们可以进行反思，也可以调用内部方法(但请确保您所做的！)。

将这种方法封装到扩展方法中，我们将得到一个很短的类：

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public static class ControlExtensions
{
public static void DoubleBuffering(this Control control, bool enable)
{
var method = typeof(Control).GetMethod("SetStyle", BindingFlags.Instance | BindingFlags.NonPublic);
method.Invoke(control, new object[] { ControlStyles.OptimizedDoubleBuffer, enable });
}
}

可以在我们的代码中轻松调用：

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InitializeComponent();

myListView.DoubleBuffering(true); //after the InitializeComponent();

所有的闪烁都消失了。

更新资料

我偶然发现了这个问题，由于这个事实，扩展方法应该(也许)更好：

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public static void DoubleBuffered(this Control control, bool enable)
{
var doubleBufferPropertyInfo = control.GetType().GetProperty("DoubleBuffered", BindingFlags.Instance | BindingFlags.NonPublic);
doubleBufferPropertyInfo.SetValue(control, enable, null);
}

为了结束这个问题，这里是一个帮助程序类，当为表单中的每个ListView或任何其他ListView的派生控件加载表单时，应调用该类。感谢" Brian Gillespie"提供的解决方案。

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public enum ListViewExtendedStyles
{
/// <summary>
/// LVS_EX_GRIDLINES
/// </summary>
GridLines = 0x00000001,
/// <summary>
/// LVS_EX_SUBITEMIMAGES
/// </summary>
SubItemImages = 0x00000002,
/// <summary>
/// LVS_EX_CHECKBOXES
/// </summary>
CheckBoxes = 0x00000004,
/// <summary>
/// LVS_EX_TRACKSELECT
/// </summary>
TrackSelect = 0x00000008,
/// <summary>
/// LVS_EX_HEADERDRAGDROP
/// </summary>
HeaderDragDrop = 0x00000010,
/// <summary>
/// LVS_EX_FULLROWSELECT
/// </summary>
FullRowSelect = 0x00000020,
/// <summary>
/// LVS_EX_ONECLICKACTIVATE
/// </summary>
OneClickActivate = 0x00000040,
/// <summary>
/// LVS_EX_TWOCLICKACTIVATE
/// </summary>
TwoClickActivate = 0x00000080,
/// <summary>
/// LVS_EX_FLATSB
/// </summary>
FlatsB = 0x00000100,
/// <summary>
/// LVS_EX_REGIONAL
/// </summary>
Regional = 0x00000200,
/// <summary>
/// LVS_EX_INFOTIP
/// </summary>
InfoTip = 0x00000400,
/// <summary>
/// LVS_EX_UNDERLINEHOT
/// </summary>
UnderlineHot = 0x00000800,
/// <summary>
/// LVS_EX_UNDERLINECOLD
/// </summary>
UnderlineCold = 0x00001000,
/// <summary>
/// LVS_EX_MULTIWORKAREAS
/// </summary>
MultilWorkAreas = 0x00002000,
/// <summary>
/// LVS_EX_LABELTIP
/// </summary>
LabelTip = 0x00004000,
/// <summary>
/// LVS_EX_BORDERSELECT
/// </summary>
BorderSelect = 0x00008000,
/// <summary>
/// LVS_EX_DOUBLEBUFFER
/// </summary>
DoubleBuffer = 0x00010000,
/// <summary>
/// LVS_EX_HIDELABELS
/// </summary>
HideLabels = 0x00020000,
/// <summary>
/// LVS_EX_SINGLEROW
/// </summary>
SingleRow = 0x00040000,
/// <summary>
/// LVS_EX_SNAPTOGRID
/// </summary>
SnapToGrid = 0x00080000,
/// <summary>
/// LVS_EX_SIMPLESELECT
/// </summary>
SimpleSelect = 0x00100000
}

public enum ListViewMessages
{
First = 0x1000,
SetExtendedStyle = (First + 54),
GetExtendedStyle = (First + 55),
}

/// <summary>
/// Contains helper methods to change extended styles on ListView, including enabling double buffering.
/// Based on Giovanni Montrone's article on <see cref="http://www.codeproject.com/KB/list/listviewxp.aspx"/>
/// </summary>
public class ListViewHelper
{
private ListViewHelper()
{
}

[DllImport("user32.dll", CharSet = CharSet.Auto)]
private static extern int SendMessage(IntPtr handle, int messg, int wparam, int lparam);

public static void SetExtendedStyle(Control control, ListViewExtendedStyles exStyle)
{
ListViewExtendedStyles styles;
styles = (ListViewExtendedStyles)SendMessage(control.Handle, (int)ListViewMessages.GetExtendedStyle, 0, 0);
styles |= exStyle;
SendMessage(control.Handle, (int)ListViewMessages.SetExtendedStyle, 0, (int)styles);
}

public static void EnableDoubleBuffer(Control control)
{
ListViewExtendedStyles styles;
// read current style
styles = (ListViewExtendedStyles)SendMessage(control.Handle, (int)ListViewMessages.GetExtendedStyle, 0, 0);
// enable double buffer and border select
styles |= ListViewExtendedStyles.DoubleBuffer | ListViewExtendedStyles.BorderSelect;
// write new style
SendMessage(control.Handle, (int)ListViewMessages.SetExtendedStyle, 0, (int)styles);
}
public static void DisableDoubleBuffer(Control control)
{
ListViewExtendedStyles styles;
// read current style
styles = (ListViewExtendedStyles)SendMessage(control.Handle, (int)ListViewMessages.GetExtendedStyle, 0, 0);
// disable double buffer and border select
styles -= styles & ListViewExtendedStyles.DoubleBuffer;
styles -= styles & ListViewExtendedStyles.BorderSelect;
// write new style
SendMessage(control.Handle, (int)ListViewMessages.SetExtendedStyle, 0, (int)styles);
}
}

CommonControls 6(XP或更高版本)中的ListView支持双缓冲。幸运的是，.NET将最新的CommonControl包装在系统上。若要启用双重缓冲，请将适当的Windows消息发送到ListView控件。

详细信息如下：
http://www.codeproject.com/KB/list/listviewxp.aspx

在.NET Winforms 2.0中，存在一个称为DoubleBuffered的受保护属性。

通过从ListView继承，可以将此受保护的属性设置为true。这将启用双重缓冲，而无需调用SendMessage。

设置DoubleBuffered属性与设置以下样式相同：