如何使用fbwf函数“FbwfCacheThresholdNotification”在C＃中 [英] How to use the fbwf function "FbwfCacheThresholdNotification" in C#

问题描述

大家好，



我试图使用微软fbwf库的FbwfCacheThresholdNotification功能。该库在嵌入式Windows XP中使用，我认为它不适用于普通的Windows。文档可以在这里找到： [ ^ ]



文档对我来说不够。我可以使用哪种托管类型来处理？



目前我尝试了以下内容：



创建代理类型：

[UnmanagedFunctionPointer（CallingConvention.StdCall）]

delegate void ThresholdNotificationDelegate（）;



传递委托给非托管函数：

[DllImport（fbwflib.dll，CallingConvention = CallingConvention.Winapi）]

静态extern UInt32 FbwfCacheThresholdNotification（UInt32阈值，[MarshalAs（ UnmanagedType.FunctionPtr）] ThresholdNotificationDelegate thresholdNotification）



当我调用函数时，我得到6作为返回值，这意味着无效句柄。



感谢您的帮助！

Hello all,

I tried to use the function "FbwfCacheThresholdNotification" of the fbwf library of microsoft. The library is used in windows XP embedded and doesn't work on normal windows I guess. The documentation can be found here: [^]

The documentation is insufficient for me. What managed type can I use for handle?

Currently I tried the following:

Create a delegate of type:
[UnmanagedFunctionPointer(CallingConvention.StdCall)]
delegate void ThresholdNotificationDelegate();

Passing that delegate to the unmanaged function:
[DllImport("fbwflib.dll", CallingConvention = CallingConvention.Winapi)]
static extern UInt32 FbwfCacheThresholdNotification(UInt32 threshold, [MarshalAs(UnmanagedType.FunctionPtr)] ThresholdNotificationDelegate thresholdNotification)

When I call the function I get "6" as return value, that means "invalid handle".

Thanks for your help!

推荐答案

参数是一个事件句柄。尝试将声明更改为：

The argument is an event handle. Try changing the declaration to:

[DllImport("fbwflib.dll", CallingConvention = CallingConvention.Winapi)]
static extern UInt32 FbwfCacheThresholdNotification(UInt32 threshold, Microsoft.Win32.SafeHandles.SafeWaitHandle thresholdNotification);

您应该能够创建一个新的 AutoResetEvent （或 ManualResetEvent ）并将其 SafeWaitHandle 属性传递给该函数。当缓存低于阈值时，将发出该事件的信号。

You should then be able to create a new AutoResetEvent (or a ManualResetEvent) and pass its SafeWaitHandle property to the function. That event will then be signalled when the cache falls below the threshold.

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