2019-5-13-WPF-从触摸消息转触摸事件

internal static class NativeMethods
{
public const int WM_TOUCH = 0x0240;
public const uint TWF_WANTPALM = 0x00000002; [DllImport("user32")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool RegisterTouchWindow(IntPtr hWnd, uint ulFlags); [DllImport("user32")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool GetTouchInputInfo(IntPtr hTouchInput, int cInputs,
[In, Out] TOUCHINPUT[] pInputs, int cbSize); [DllImport("user32")]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern void CloseTouchInputHandle(IntPtr lParam);
}

public MainWindow()
{
InitializeComponent(); SourceInitialized += MainWindow_SourceInitialized;
} private void MainWindow_SourceInitialized(object sender, EventArgs e)
{
MessageTouchDevice.UseMessageTouch(this);
}

/// <summary>
/// 使用消息触摸
/// 注意 开启了消息触摸之后，原有的 WPF 触摸将会无法再次使用
/// </summary>
public static void UseMessageTouch(Window window)
{
// 先禁用 WPF 触摸
TabletHelper.DisableWPFTabletSupport(hWnd); NativeMethods.RegisterTouchWindow(hWnd, NativeMethods.TWF_WANTPALM);
HwndSource source = HwndSource.FromHwnd(hWnd); source.AddHook((IntPtr hwnd, int msg, IntPtr param, IntPtr lParam, ref bool handled) =>
{
WndProc(window, msg, param, lParam, ref handled);
return IntPtr.Zero;
});
}

private static void WndProc(Window window, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
if (msg == NativeMethods.WM_TOUCH)
{
}
}

var inputCount = wParam.ToInt32() & 0xffff;

var inputs = new NativeMethods.TOUCHINPUT[inputCount]; NativeMethods.GetTouchInputInfo(lParam, inputCount, inputs, NativeMethods.TouchInputSize);

[StructLayout(LayoutKind.Sequential)]
internal struct TOUCHINPUT
{
/// <summary>
/// 触控输入的 X 坐标（水平点）。此成员用物理屏幕坐标的像素的百分之一表示
/// </summary>
public int X; /// <summary>
/// 触控输入的 y 坐标（垂直点）。此成员用物理屏幕坐标的像素的百分之一表示
/// </summary>
public int Y; /// <summary>
/// 源输入设备的设备句柄。触控输入提供程序在运行时为每个设备指定一个唯一的提供程序
/// </summary>
public IntPtr Source; /// <summary>
/// 一个用于区别某个特定触控输入的触控点标识符。此值在触控点序列中从触控点下降到重新上升的整个过程中保持一致。稍后可对后续触控点重用一个 ID
/// </summary>
public int DwID; /// <summary>
/// 用于指定触控点按住、释放和移动的各个方面
/// </summary>
public TOUCHEVENTF DwFlags; /// <summary>
/// 指定结构中包含有效值的可选字段。可选字段中的有效信息的可用性是特定于设备的
/// </summary>
public TOUCHINPUTMASK DwMask; /// <summary>
/// 事件的时间戳（以毫秒为单位）。使用方应用程序应通知系统不对此字段进行验证
/// </summary>
public int DwTime; public IntPtr DwExtraInfo; /// <summary>
/// 触控区域的宽度用物理屏幕坐标的像素的百分之一表示。只有在 <see cref="DwMask"/> 成员设置了 TOUCHEVENTFMASK_CONTACTAREA 标记的情况下，此值才会有效
/// </summary>
public int CxContact; /// <summary>
/// 触控区域的高度用物理屏幕坐标的像素的百分之一表示。只有在 <see cref="DwMask"/> 成员设置了 TOUCHEVENTFMASK_CONTACTAREA 标记的情况下，此值才会有效
/// </summary>
public int CyContact;
}

var position = new Point(input.X / 100.0, input.Y / 100.0);
var size = new Size(input.CxContact / 100.0, input.CyContact / 100.0);

private static readonly Dictionary<int, MessageTouchDevice>
_devices = new Dictionary<int, MessageTouchDevice>();

if (!_devices.TryGetValue(input.DwID, out var device))
{
device = new MessageTouchDevice(input.DwID, window);
_devices.Add(input.DwID, device);
}

if (!device.IsActive && input.DwFlags.HasFlag(NativeMethods.TOUCHEVENTF.TOUCHEVENTF_DOWN))
{
device.Position = position;
device.Size = size;
device.Down();
}

/// <summary>
/// 触摸点
/// </summary>
private Point Position { set; get; } /// <summary>
/// 触摸大小
/// </summary>
private Size Size { set; get; } public override TouchPoint GetTouchPoint(IInputElement relativeTo)
{
return new TouchPoint(this, Position, new Rect(Position, Size), TouchAction);
}