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Fixed issues with BasicMessageWindow that caused creation failures and WndProc call failures.

pull/211/head
dahall 2021-02-08 15:31:59 -07:00
parent 6c4a37655b
commit 03cb7bdda6
1 changed files with 20 additions and 17 deletions
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37
PInvoke/User32/BasicMessageWindow.cs
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@ -19,31 +19,28 @@ namespace Vanara.PInvoke
public delegate bool BasicMessageWindowFilter(HWND hwnd, uint msg, IntPtr wParam, IntPtr lParam, out IntPtr lReturn);
/// <summary>Simple window to process messages.</summary>
/// <seealso cref="System.MarshalByRefObject"/>
/// <seealso cref="System.IDisposable"/>
/// <seealso cref="Vanara.PInvoke.IHandle"/>
/// <seealso cref="MarshalByRefObject"/>
/// <seealso cref="IDisposable"/>
/// <seealso cref="IHandle"/>
public class BasicMessageWindow : MarshalByRefObject, IDisposable, IHandle
{
private readonly SafeHWND hwnd;
private readonly WeakReference weakSelfRef;
private bool isDisposed;
private WindowClass wCls;
/// <summary>Initializes a new instance of the <see cref="BasicMessageWindow"/> class.</summary>
/// <param name="callback">Specifies the callback method to use to process messages.</param>
public BasicMessageWindow(BasicMessageWindowFilter callback = null)
{
MessageFilter = callback;
ClassName = $"{GetType().Name}+{Guid.NewGuid()}";
weakSelfRef = new WeakReference(this);
hwnd = CreateWindow();
}
/// <summary>Finalizes an instance of the <see cref="BasicMessageWindow"/> class.</summary>
~BasicMessageWindow() => Dispose(false);
/// <summary>Gets the name of the class.</summary>
/// <value>The name of the class.</value>
public string ClassName { get; private set; }
/// <summary>Gets the handle.</summary>
/// <value>The handle.</value>
public HWND Handle => hwnd;
@ -52,6 +49,10 @@ namespace Vanara.PInvoke
/// <value>The callback method.</value>
public BasicMessageWindowFilter MessageFilter { get; set; }
/// <summary>Gets the name of the class.</summary>
/// <value>The name of the class.</value>
public string ClassName => wCls?.ClassName;
/// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
public void Dispose()
{
@ -68,10 +69,9 @@ namespace Vanara.PInvoke
/// </summary>
protected virtual SafeHWND CreateWindow()
{
var hInst = GetModuleHandle();
var wcx = new WNDCLASSEX { cbSize = (uint)Marshal.SizeOf(typeof(WNDCLASSEX)), lpfnWndProc = WndProc, hInstance = hInst, lpszClassName = ClassName };
var atom = Win32Error.ThrowLastErrorIfNull(Macros.MAKEINTATOM(RegisterClassEx(wcx)));
return Win32Error.ThrowLastErrorIfInvalid(CreateWindowEx(lpClassName: atom, hWndParent: HWND.HWND_MESSAGE, hInstance: hInst));
HINSTANCE hInst = GetModuleHandle();
wCls = new WindowClass($"{GetType().Name}+{Guid.NewGuid()}", hInst, WndProc);
return Win32Error.ThrowLastErrorIfInvalid(CreateWindowEx(0, wCls.Atom, hWndParent: HWND.HWND_MESSAGE, hInstance: hInst));
}
/// <summary>Releases unmanaged and - optionally - managed resources.</summary>
@ -85,13 +85,16 @@ namespace Vanara.PInvoke
isDisposed = true;
hwnd?.Dispose(); // Calls DestroyWindow
UnregisterClass(ClassName, GetModuleHandle());
ClassName = null;
wCls?.Unregister();
}
private IntPtr WndProc(HWND hwnd, uint msg, IntPtr wParam, IntPtr lParam) =>
MessageFilter is null || !MessageFilter.Invoke(hwnd, msg, wParam, lParam, out var lRet)
private IntPtr WndProc(HWND hwnd, uint msg, IntPtr wParam, IntPtr lParam)
{
if (msg == (uint)WindowMessage.WM_NCCREATE)
return (IntPtr)1;
return !weakSelfRef.IsAlive || weakSelfRef.Target is null || MessageFilter is null || !MessageFilter.Invoke(hwnd, msg, wParam, lParam, out IntPtr lRet)
? DefWindowProc(hwnd, msg, wParam, lParam)
: lRet;
}
}
}