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问题?

请问朋友InvokeHelper()函数的是怎么用法的?里面的参数都代表怎么意思来得?
比如:
InvokeHelper(DISPID_REFRESH, DISPATCH_METHOD, VT_EMPTY, NULL, NULL)
帮帮忙,可以吗?

搜索更多相关主题的帖子: InvokeHelper　NULL　METHOD　DISPATCH　DISPID　

第 2 楼

得分:0

1、播放文件的函数：

void CActiveMovie3::Run()
{
　　InvokeHelper(0x60020001, DISPATCH_METHOD, VT_EMPTY, NULL, NULL);
}

　　2、暂停播放的函数： void CActiveMovie3::Pause()

{
　　InvokeHelper(0x60020002, DISPATCH_METHOD, VT_EMPTY, NULL, NULL);
}

　　4、停止播放的函数： void CActiveMovie3::Stop()

{
　　InvokeHelper(0x60020003, DISPATCH_METHOD, VT_EMPTY, NULL, NULL);
}

　　5、获得文件的函数： CString CActiveMovie3::GetFileName()

{
　　CString result;
　　InvokeHelper(0xb, DISPATCH_PROPERTYGET, VT_BSTR, (void*)&result, NULL);
　　return result;
}

　　6、设置文件的函数： void CActiveMovie3::SetFileName(LPCTSTR lpszNewValue)

{
　　static BYTE parms[] = VTS_BSTR;
　　InvokeHelper(0xb, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
　　lpszNewValue);
}

　　7、获得播放位置的函数： double CActiveMovie3::GetCurrentPosition()

{
　　double result;
　　InvokeHelper(0xd, DISPATCH_PROPERTYGET, VT_R8, (void*)&result, NULL);
　　return result;
}

　　8、设置播放位置的函数： void CActiveMovie3::SetCurrentPosition(double newValue)

{
　　static BYTE parms[] = VTS_R8;
　　InvokeHelper(0xd, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms, newValue);
}

　　9、获得音量的函数： long CActiveMovie3::GetVolume()

{
　　long result;
　　InvokeHelper(0x13, DISPATCH_PROPERTYGET, VT_I4, (void*)&result, NULL);
　　return result;
}

　　10、设置音量的函数： void CActiveMovie3::SetVolume(long nNewValue)

{
　　static BYTE parms[] = VTS_I4;
　　InvokeHelper(0x13, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms, nNewValue);
}

　　11、设置自动开始播放的函数： void CActiveMovie3::SetAutoStart(BOOL bNewValue)

{
　　static BYTE parms[] = VTS_BOOL;
　　InvokeHelper(0x28, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms, bNewValue);
}

本来无一物，何处惹尘埃
It is empty at all here, Why pm 2.5 is so TMD high!

第 3 楼

得分:0

COleDispatchDriver::InvokeHelper

void InvokeHelper( DISPID dwDispID, WORD wFlags, VARTYPE vtRet, void* pvRet, const BYTE FAR* pbParamInfo, ... );
throw( COleException );
throw( COleDispatchException );

Parameters

dwDispID

Identifies the method or property to be invoked. This value is usually supplied by ClassWizard.

wFlags

Flags describing the context of the call to IDispatch::Invoke. For possible values, see the Platform SDK.

vtRet

Specifies the type of the return value. For possible values, see the Remarks section.

pvRet

Address of the variable that will receive the property value or return value. It must match the type specified by vtRet.

pbParamInfo

Pointer to a null-terminated string of bytes specifying the types of the parameters following pbParamInfo.

...

Variable list of parameters, of types specified in pbParamInfo.

Remarks

Calls the object method or property specified by dwDispID, in the context specified by wFlags. The pbParamInfo parameter specifies the types of the parameters passed to the method or property. The variable list of arguments is represented by ... in the syntax declaration.

Possible values for the vtRet argument are taken from the VARENUM enumeration. Possible values are as follows:

Symbol	Return Type
VT_EMPTY	void
VT_I2	short
VT_I4	long
VT_R4	float
VT_R8	double
VT_CY	CY
VT_DATE	DATE
VT_BSTR	BSTR
VT_DISPATCH	LPDISPATCH
VT_ERROR	SCODE
VT_BOOL	BOOL
VT_VARIANT	VARIANT
VT_UNKNOWN	LPUNKNOWN

The pbParamInfo argument is a space-separated list of VTS_ constants. One or more of these values, separated by spaces (not commas), specifies the function’s parameter list. Possible values are listed with the EVENT_CUSTOM macro.

This function converts the parameters to VARIANTARG values, then invokes the IDispatch::Invoke method. If the call to Invoke fails, this function will throw an exception. If the SCODE (status code) returned by IDispatch::Invoke is DISP_E_EXCEPTION, this function throws a COleException object; otherwise it throws a COleDispatchException.

For more information, see VARIANTARG, IDispatch, IDispatch::Invoke, and Structure of COM Error Codes in the Platform SDK.