| title | author | date | CreateTime | categories |
|---|---|---|---|---|
|
WPF 判断USB插拔
|
lindexi
|
2018-08-10 19:16:53 +0800
|
2018-8-5 13:0:31 +0800
|
WPF
|
本文告诉大家如何在 WPF 在用户插拔 USB 收到消息
首先需要在一个窗口重写OnSourceInitialized，在这里可以拿到窗口的指针
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized(e); var hwndSource = PresentationSource.FromVisual(this) as HwndSource;
hwndSource?.AddHook(new HwndSourceHook(WndProc));
}
在 USB 插拔可以收到 DEVICECHANGE 消息
private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam, ref bool handled)
{
if (msg == (int) WM.DEVICECHANGE)
{
Debug.WriteLine(DateTime.Now.ToString() + " " + "设备发生插拔\r\n");
}
return IntPtr.Zero;
}
这里的 WM.DEVICECHANGE 就是 537 ，关于其他的消息请看win 消息
如果需要获得更多的 USB 信息就建议安装 WpfUsbMonitor 通过这个可以简单知道 USB 是否插入
使用这个的方法很简单，请看下面代码
public MainWindow()
{
InitializeComponent(); var usbMonitor = new UsbMonitor(this);
usbMonitor.UsbUpdate += UsbMonitor_UsbUpdate;
} private void UsbMonitor_UsbUpdate(object sender, UsbEventArgs e)
{
Debug.WriteLine($@"
USB { e.Action.ToString()}
USB 名 {e.Name}
USB 类别{e.Class}
USB GUID{e.ClassGuid}");
}
如果不想安装库，只是需要知道是插入还是拔出，可以使用 WMI 的方法，需要安装 System.Management 更多关于这方面请看 WPF 读取硬件序列号
public MainWindow()
{
InitializeComponent(); ManagementEventWatcher watcher = new ManagementEventWatcher();
WqlEventQuery query = new WqlEventQuery("SELECT * FROM Win32_VolumeChangeEvent WHERE EventType = 2 or EventType = 3"); watcher.EventArrived += (s, e) =>
{
string driveName = e.NewEvent.Properties["DriveName"].Value.ToString();
EventType eventType = (EventType) (Convert.ToInt16(e.NewEvent.Properties["EventType"].Value)); string eventName = Enum.GetName(typeof(EventType), eventType); Console.WriteLine("{0}: {1} {2}", DateTime.Now, driveName, eventName);
}; watcher.Query = query;
watcher.Start();
} public enum EventType
{
Inserted = 2,
Removed = 3
}
如果需要知道是哪个设备进行插拔，可以使用下面方法
public MainWindow()
{
InitializeComponent(); WqlEventQuery insertQuery = new WqlEventQuery("SELECT * FROM __InstanceCreationEvent WITHIN 2 WHERE TargetInstance ISA 'Win32_USBHub'"); ManagementEventWatcher insertWatcher = new ManagementEventWatcher(insertQuery);
insertWatcher.EventArrived += (s, e) =>
{
Console.WriteLine("插入设备"); var instance = (ManagementBaseObject) e.NewEvent["TargetInstance"];
var description = instance.Properties["Description"]; Console.WriteLine(description.Name + " = " + description.Value); var deviceId = instance.Properties["DeviceID"];
Console.WriteLine(deviceId.Name + " = " + deviceId.Value); };
insertWatcher.Start(); WqlEventQuery removeQuery = new WqlEventQuery("SELECT * FROM __InstanceDeletionEvent WITHIN 2 WHERE TargetInstance ISA 'Win32_USBHub'");
ManagementEventWatcher removeWatcher = new ManagementEventWatcher(removeQuery);
removeWatcher.EventArrived += (s, e) =>
{
Console.WriteLine("移除设备"); var instance = (ManagementBaseObject) e.NewEvent["TargetInstance"];
var description = instance.Properties["Description"]; Console.WriteLine(description.Name + " = " + description.Value); var deviceId = instance.Properties["DeviceID"];
Console.WriteLine(deviceId.Name + " = " + deviceId.Value);
};
removeWatcher.Start();
}