.Net 知识点
1. [WPF] 代码构建 ItemsPanel
var itemsPanelTemplate = new ItemsPanelTemplate();
var factory = new FrameworkElementFactory(typeof(AnimatingStackPanel));
factory.SetValue(StackPanel.OrientationProperty, Orientation.Vertical);
itemsPanelTemplate.VisualTree = factory;
2. [WPF] 统一Xaml命名空间
// 声明命名空间，注意如果命名空间不存在，会出现编译错误，且比较难以定位
[assembly: XmlnsDefinition("http://ssm.app.com", "ssm.ui.Assists")]
// 声明命名控件缩写前缀
[assembly: XmlnsPrefix("http://ssm.app.com", "ssm")]
2.1. [WPF] .net core 工程添加 XmlnsDefinition 特性
参考 WPF attributes coming to csproj or remain in AssemblyInfo? · Issue #294 · dotnet/wpf (github.com)
方案：在任意cs文件中添加如下代码即可。建议添加单独的Markup.cs文件用于存放这些代码。
[assembly: XmlnsDefinition("https://github.com/liwuqingxin", "NLNet.Kit.MVVM.NSConverters")]
[assembly: XmlnsPrefix("https://github.com/liwuqingxin", "nlnet")]
3. [WPF] 使用 WinForm，设置样式可用
参考 为什么Winform控件在WPF中的样式和真正WinForm窗体内的不同？ - 知乎 (zhihu.com)
System.Windows.Forms.Application.EnableVisualStyles();
System.Windows.Forms.Application.SetCompatibleTextRenderingDefault(false);
4. [WPF] 设置动画帧数
参考 WPF:关于Animation的CPU消耗 - 木木子 - 博客园 (cnblogs.com)
Timeline.DesiredFrameRateProperty.OverrideMetadata(typeof(Timeline), new FrameworkPropertyMetadata
{
DefaultValue = framePerSecond
});
5. [WPF] TextBox控件对于鼠标单击获取焦点后的全选
参考 WPF中TextBox控件对于鼠标单击获取焦点后的全选 - 罗天大兵 - 博客园 (cnblogs.com)
/// <summary>
/// 键盘焦点处于 TextBox 时，选中所有文本。
/// </summary>
private static void TbxSelectAllOnGotKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
{
if (sender.CheckIfIsNot<TextBox>(out var tbx)) return;
tbx.SelectAll();
tbx.PreviewMouseDown -= TbxSelectAll_OnPreviewMouseDown;
}
/// <summary>
/// 失去键盘焦点时，添加鼠标按下前事件。
/// </summary>
private static void TbxSelectAllOnLostKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
{
if (e.Source.CheckIfIsNot<TextBox>(out var tbx)) return;
tbx.PreviewMouseDown += TbxSelectAll_OnPreviewMouseDown;
}
/// <summary>
/// 鼠标按下前事件。
/// </summary>
private static void TbxSelectAllOnPreviewMouseDown(object sender, MouseButtonEventArgs e)
{
if (e.Source.CheckIfIsNot<TextBox>(out var tbx)) return;
tbx.Focus();
// BUG 这里不设置 Handled，选中后会被取消。而设置 Handled，会导致内部点击逻辑无法完成，比如内部按钮的点击，第一次无法被触发。
e.Handled = true;
}
6. [WPF] DataGrid 判断行占位符
if (e.Row.Item.Equals(CollectionView.NewItemPlaceholder))
{
return;
}
7. [WPF] RichTextBox 自适应尺寸/取消自动换行
参考
[WPF]根据内容自动设置大小的RichTextBox - 周银辉 - 博客园 (cnblogs.com)
C#/WPF: Disable Text-Wrap of RichTextBox - Stack Overflow
private double AdjustSizeByContent(FlowDocument document, double margin)
{
var formattedText = GetFormattedText(document);
document.PageWidth = Math.Min(MaxWidth, Math.Max(MinWidth, formattedText.WidthIncludingTrailingWhitespace + margin));
return document.PageWidth;
}
private static FormattedText GetFormattedText(FlowDocument doc)
{
var output = new FormattedText(
GetText(doc),
CultureInfo.CurrentCulture,
doc.FlowDirection,
new Typeface(doc.FontFamily, doc.FontStyle, doc.FontWeight, doc.FontStretch),
doc.FontSize,
doc.Foreground);
var offset = 0;
foreach (var textElement in GetRunsAndParagraphs(doc))
{
if (textElement is Run run)
{
var count = run.Text.Length;
output.SetFontFamily(run.FontFamily, offset, count);
output.SetFontSize(run.FontSize, offset, count);
output.SetFontStretch(run.FontStretch, offset, count);
output.SetFontStyle(run.FontStyle, offset, count);
output.SetFontWeight(run.FontWeight, offset, count);
output.SetForegroundBrush(run.Foreground, offset, count);
output.SetTextDecorations(run.TextDecorations, offset, count);
offset += count;
}
else
{
offset += Environment.NewLine.Length;
}
}
return output;
}
private static IEnumerable<TextElement> GetRunsAndParagraphs(FlowDocument doc)
{
for (var position = doc.ContentStart; position != null && position.CompareTo(doc.ContentEnd) <= 0; position = position.GetNextContextPosition(LogicalDirection.Forward))
{
if (position.GetPointerContext(LogicalDirection.Forward) != TextPointerContext.ElementEnd) continue;
switch (position.Parent)
{
case Run run:
yield return run;
break;
case Paragraph para:
yield return para;
break;
case LineBreak lineBreak:
yield return lineBreak;
break;
}
}
}
8. [WPF] Xaml动画情景：计时器剩余时间的状态，最后10s高亮
<!-- 计时器剩余时间的状态，最后10s高亮 -->
<DataTrigger Binding="{Binding Path=Timer.State}" Value="Notice">
<Setter TargetName="TbkTimer" Property="FontSize" Value="{DynamicResource Title4}"/>
</DataTrigger>
<DataTrigger Binding="{Binding Path=Timer.State}" Value="Attention">
<Setter TargetName="TbkTimer" Property="FontStyle" Value="Italic"/>
<DataTrigger.EnterActions>
<BeginStoryboard>
<Storyboard>
<ColorAnimation Duration="0:0:0.5" To="#FFFF6E41"
Storyboard.TargetName="TbkTimer"
Storyboard.TargetProperty="(Control.Foreground).(SolidColorBrush.Color)"/>
<ColorAnimation Duration="0:0:0.5" To="#FFFF6E41"
Storyboard.TargetName="TbkTimerText"
Storyboard.TargetProperty="(Control.Foreground).(SolidColorBrush.Color)"/>
<DoubleAnimation Duration="0:0:0.2" To="72"
Storyboard.TargetName="TbkTimer"
Storyboard.TargetProperty="FontSize">
<DoubleAnimation.EasingFunction>
<ExponentialEase EasingMode="EaseInOut" Exponent="0.75"/>
</DoubleAnimation.EasingFunction>
</DoubleAnimation>
<ThicknessAnimation Duration="0:0:0.2" To="15,0"
Storyboard.TargetName="TbkTimer"
Storyboard.TargetProperty="Margin">
<ThicknessAnimation.EasingFunction>
<ExponentialEase EasingMode="EaseInOut" Exponent="0.75"/>
</ThicknessAnimation.EasingFunction>
</ThicknessAnimation>
</Storyboard>
</BeginStoryboard>
</DataTrigger.EnterActions>
<DataTrigger.ExitActions>
<BeginStoryboard>
<Storyboard>
<ColorAnimation Duration="0:0:0.5"
Storyboard.TargetName="TbkTimer"
Storyboard.TargetProperty="(Control.Foreground).(SolidColorBrush.Color)"/>
<ColorAnimation Duration="0:0:0.5"
Storyboard.TargetName="TbkTimerText"
Storyboard.TargetProperty="(Control.Foreground).(SolidColorBrush.Color)"/>
<DoubleAnimation Duration="0:0:0.2"
Storyboard.TargetName="TbkTimer"
Storyboard.TargetProperty="FontSize">
<DoubleAnimation.EasingFunction>
<ExponentialEase EasingMode="EaseInOut" Exponent="0.75"/>
</DoubleAnimation.EasingFunction>
</DoubleAnimation>
<ThicknessAnimation Duration="0:0:0.2"
Storyboard.TargetName="TbkTimer"
Storyboard.TargetProperty="Margin">
<ThicknessAnimation.EasingFunction>
<ExponentialEase EasingMode="EaseInOut" Exponent="0.75"/>
</ThicknessAnimation.EasingFunction>
</ThicknessAnimation>
</Storyboard>
</BeginStoryboard>
</DataTrigger.ExitActions>
</DataTrigger>
9. [WPF] 设计模式资源
注意，
- 不要覆盖Source属性，这会导致设计器无法正常加载；
- 不要引用资源工程，这会导致设计器无法正常加载，且报错“未找到路径.....的一部分”。
- iconfont的引用，如果字体文件不是在同工程，则设计模式下显示为▯。以链接的形式添加该字体文件到使用的工程即可解决，如果仅设计模式需要，将文件属性改为DesignData。
public class DesignResourceDictionary : ResourceDictionary
{
/// <summary>
/// Gets or sets the design time source.
/// </summary>
/// <value>
/// The design time source.
/// </value>
public Uri DesignSource
{
get => Source;
set
{
//if ((bool) DesignerProperties.IsInDesignModeProperty.GetMetadata(typeof(DependencyObject)).DefaultValue)
//{
// Source = value;
//}
if (VisualUtil.IsInDesignMode2)
{
Source = value;
}
}
}
}
10. [C#] 调整（扩展）屏幕亮度
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Text.RegularExpressions;
using System.Windows;
// ReSharper disable FieldCanBeMadeReadOnly.Global
// ReSharper disable MemberCanBePrivate.Global
// ReSharper disable ClassWithVirtualMembersNeverInherited.Global
// ReSharper disable InconsistentNaming
// ReSharper disable ClassNeverInstantiated.Global
// 参考：https://github.com/emoacht/Monitorian
namespace ScreenManager
{
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public struct PHYSICAL_MONITOR
{
public IntPtr hPhysicalMonitor;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 128)]
public string szPhysicalMonitorDescription;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public struct MONITORINFOEX
{
public uint cbSize;
public RECT rcMonitor;
public RECT rcWork;
public uint dwFlags;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
public string szDevice;
}
[StructLayout(LayoutKind.Sequential)]
public struct RECT
{
public int left;
public int top;
public int right;
public int bottom;
public static implicit operator Rect(RECT rect)
{
if ((rect.right < rect.left) || (rect.bottom < rect.top))
return Rect.Empty;
return new Rect(
rect.left,
rect.top,
rect.right - rect.left,
rect.bottom - rect.top);
}
public static implicit operator RECT(Rect rect)
{
return new RECT
{
left = (int)rect.Left,
top = (int)rect.Top,
right = (int)rect.Right,
bottom = (int)rect.Bottom
};
}
}
public class SafePhysicalMonitorHandle : SafeHandle
{
public SafePhysicalMonitorHandle(IntPtr handle) : base(IntPtr.Zero, true)
{
this.handle = handle; // IntPtr.Zero may be a valid handle.
}
public override bool IsInvalid => false; // The validity cannot be checked by the handle.
protected override bool ReleaseHandle()
{
return ScreenHelper.DestroyPhysicalMonitor(handle);
}
}
public class HandleItem
{
public byte DisplayIndex;
public RECT MonitorRect;
public IntPtr MonitorHandle;
public HandleItem(byte displayIndex, RECT monitorRect, IntPtr monitorHandle)
{
DisplayIndex = displayIndex;
MonitorRect = monitorRect;
MonitorHandle = monitorHandle;
}
}
public class ScreenHelper : IDisposable
{
#region Win32
[DllImport("User32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool EnumDisplayMonitors(
IntPtr hdc,
IntPtr lprcClip,
MonitorEnumProc lpfnEnum,
IntPtr dwData);
[return: MarshalAs(UnmanagedType.Bool)]
private delegate bool MonitorEnumProc(
IntPtr hMonitor,
IntPtr hdcMonitor,
IntPtr lprcMonitor,
IntPtr dwData);
[DllImport("User32.dll", EntryPoint = "GetMonitorInfoW")]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool GetMonitorInfo(
IntPtr hMonitor,
ref MONITORINFOEX lpmi);
[DllImport("user32.dll", EntryPoint = "MonitorFromWindow")]
public static extern IntPtr MonitorFromWindow([In] IntPtr hwnd, uint dwFlags);
[DllImport("dxva2.dll", EntryPoint = "DestroyPhysicalMonitors")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool DestroyPhysicalMonitors(uint dwPhysicalMonitorArraySize, ref PHYSICAL_MONITOR[] pPhysicalMonitorArray);
[DllImport("dxva2.dll", EntryPoint = "GetNumberOfPhysicalMonitorsFromHMONITOR")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool GetNumberOfPhysicalMonitorsFromHMONITOR(IntPtr hMonitor, ref uint pdwNumberOfPhysicalMonitors);
[DllImport("dxva2.dll", EntryPoint = "GetPhysicalMonitorsFromHMONITOR")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool GetPhysicalMonitorsFromHMONITOR(IntPtr hMonitor, uint dwPhysicalMonitorArraySize, [Out] PHYSICAL_MONITOR[] pPhysicalMonitorArray);
[DllImport("dxva2.dll", EntryPoint = "GetMonitorBrightness")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool GetMonitorBrightness(IntPtr handle, ref uint minimumBrightness, ref uint currentBrightness, ref uint maxBrightness);
[DllImport("dxva2.dll", EntryPoint = "SetMonitorBrightness")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool SetMonitorBrightness(IntPtr handle, uint newBrightness);
[DllImport("Dxva2.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool SetMonitorBrightness(SafePhysicalMonitorHandle hMonitor, uint dwNewBrightness);
[DllImport("Dxva2.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool DestroyPhysicalMonitor(IntPtr hMonitor);
#endregion
private PHYSICAL_MONITOR[] _physicalMonitorArray;
private readonly uint _physicalMonitorsCount = 0;
private readonly IntPtr _firstMonitorHandle;
private readonly uint _minValue = 0;
private readonly uint _maxValue = 0;
private uint _currentValue = 0;
public ScreenHelper(/*IntPtr windowHandle*/)
{
var handleItems = GetMonitorHandles();
//var dwFlags = 0u;
//var ptr = MonitorFromWindow(windowHandle, dwFlags);
foreach (var handleItem in handleItems)
{
if (!GetNumberOfPhysicalMonitorsFromHMONITOR(handleItem.MonitorHandle, ref _physicalMonitorsCount))
{
Console.WriteLine("Cannot get monitor count!");
continue;
throw new Exception("Cannot get monitor count!");
}
_physicalMonitorArray = new PHYSICAL_MONITOR[_physicalMonitorsCount];
if (!GetPhysicalMonitorsFromHMONITOR(handleItem.MonitorHandle, _physicalMonitorsCount, _physicalMonitorArray))
{
Console.WriteLine("Cannot get physical monitor handle!");
continue;
throw new Exception("Cannot get physical monitor handle!");
}
_firstMonitorHandle = _physicalMonitorArray[0].hPhysicalMonitor;
if (!GetMonitorBrightness(_firstMonitorHandle, ref _minValue, ref _currentValue, ref _maxValue))
{
Console.WriteLine("Cannot get monitor brightness!");
continue;
throw new Exception("Cannot get monitor brightness!");
}
}
}
private static bool TryGetDisplayIndex(string deviceName, out byte index)
{
// The typical format of device name is as follows:
// EnumDisplayDevices (display), GetMonitorInfo : \\.\DISPLAY[index starting at 1]
// EnumDisplayDevices (monitor) : \\.\DISPLAY[index starting at 1]\Monitor[index starting at 0]
var match = Regex.Match(deviceName, @"DISPLAY(?<index>\d{1,2})\s*$");
if (match.Success)
{
index = byte.Parse(match.Groups["index"].Value);
return true;
}
index = 0;
return false;
}
public static HandleItem[] GetMonitorHandles()
{
var handleItems = new List<HandleItem>();
if (EnumDisplayMonitors(IntPtr.Zero, IntPtr.Zero, Proc, IntPtr.Zero))
{
return handleItems.ToArray();
}
return Array.Empty<HandleItem>();
bool Proc(IntPtr monitorHandle, IntPtr hdcMonitor, IntPtr lprcMonitor, IntPtr dwData)
{
var monitorInfo = new MONITORINFOEX
{
cbSize = (uint)Marshal.SizeOf<MONITORINFOEX>()
};
if (GetMonitorInfo(monitorHandle, ref monitorInfo))
{
if (TryGetDisplayIndex(monitorInfo.szDevice, out byte displayIndex))
{
handleItems.Add(new HandleItem(
displayIndex: displayIndex,
monitorRect: monitorInfo.rcMonitor,
monitorHandle: monitorHandle));
}
}
return true;
}
}
public void SetBrightness(int newValue) // 0 ~ 100
{
newValue = Math.Min(newValue, Math.Max(0, newValue));
_currentValue = (_maxValue - _minValue) * (uint)newValue / 100u + _minValue;
SetMonitorBrightness(_firstMonitorHandle, _currentValue);
}
/// <summary>
/// Sets raw brightness not represented in percentage.
/// </summary>
/// <param name="physicalMonitorHandle">Physical monitor handle</param>
/// <param name="brightness">Raw brightness (not always 0 to 100)</param>
/// <param name="isHighLevelBrightnessSupported">Whether high level function is supported</param>
/// <returns>Result</returns>
public void SetBrightness(SafePhysicalMonitorHandle physicalMonitorHandle, uint brightness, bool isHighLevelBrightnessSupported = true)
{
SetMonitorBrightness(physicalMonitorHandle, brightness);
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
if (_physicalMonitorsCount > 0)
{
DestroyPhysicalMonitors(_physicalMonitorsCount, ref _physicalMonitorArray);
}
}
}
}
}
