How to log name/path of clicked control in WPF? - wpf

Question

I use the following code to log every click in our WinForms application. In essence it looks up a control from its HWND and then prints the types and names of the control and all of its parents. Something like MainForm"myWindow">TabPanel"mainTab">Button"save"
internal class ClickLogger : IMessageFilter
{
private const int WM_LBUTTONDOWN = 0x0201;
private const int WM_LBUTTONDBLCLK = 0x0203;
private const int WM_RBUTTONDOWN = 0x0204;
private const int MaxRecurseDepth = 30;
private readonly ILogger _log;
public ClickLogger(ILogger logger)
{
_log = logger;
}
[DebuggerStepThrough]
public bool PreFilterMessage(ref Message message)
{
if (message.Msg == WM_LBUTTONDOWN
|| message.Msg == WM_RBUTTONDOWN
|| message.Msg == WM_LBUTTONDBLCLK)
{
string path = "Unknown";
Control ctl = Control.FromHandle(message.HWnd);
if (ctl != null)
{
path = PathFromControl(ctl, MaxRecurseDepth).ToString();
}
string logEntry = string.Format("{0} Click on {1}",
WndMsgToClickName(message.Msg), path);
if (_log.IsInfoEnabled)
{
_log.Info(logEntry);
}
}
return false;
}
private StringBuilder PathFromControl(Control control, int maxDepth)
{
if(maxDepth == 0)
{
_log.Warn("Max recursion {0} reached whilst resolving path of control", MaxRecurseDepth);
return new StringBuilder("ERR");
}
string name = control.GetType().Name;
if (control.Name.IsNotBlank())
{
name = name + "\"" + control.Name + "\"";
}
if (control.Parent != null && control.Parent != control)
{
return PathFromControl(control.Parent, maxDepth - 1).Append(">").Append(name);
}
return new StringBuilder(name);
}
public void Initialize()
{
Application.AddMessageFilter(this);
}
private static string WndMsgToClickName(int msgId)
{
switch (msgId)
{
case WM_LBUTTONDOWN:
return "Left";
case WM_LBUTTONDBLCLK:
return "Double";
case WM_RBUTTONDOWN:
return "Right";
default:
return "0x" + Convert.ToString(msgId, 16);
}
}
}
Recently we've started to mix WPF and WinForms and the above click logger simply prints "Unknown" for any click on a WPF control.
Is there a way I can perform a similar trick for WPF controls? A method that would work across technologies would be great.

Answer 1

well, it doesn't exactly work across technologies but for wpf you can use a combination of this to get the clicks and any of the helpers in this question to cycle through the parents to get the path.