我想要一段c++调用COM组件中yh_call ( _bstr_t ls_in_data, BSTR * ls_out_data, long * appcode, BSTR * appmsg ) 函数的代码

好的，以下是一个简单的C语言代码示例，用于调用COM组件中的yh_call函数：

#include <windows.h>
#include <tchar.h>
#include <stdio.h>

// 定义COM组件的CLSID
const CLSID CLSID_Component = {0x12345678, 0x1234, 0x5678, {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF}};

int main()
{
    HRESULT hr;
    CoInitialize(NULL);

    // 创建COM组件实例
    IUnknown* pUnknown = NULL;
    hr = CoCreateInstance(CLSID_Component, NULL, CLSCTX_INPROC_SERVER, IID_IUnknown, (void **)&pUnknown);
    if (FAILED(hr)) {
        printf("Failed to create component instance. Error code: 0x%x", hr);
        return hr;
    }

    // 查询COM组件的IUnknown接口
    IUnknown* pIUnknown = NULL;
    hr = pUnknown->QueryInterface(IID_IUnknown, (void **)&pIUnknown);
    if (FAILED(hr)) {
        printf("Failed to get IUnknown interface. Error code: 0x%x", hr);
        pUnknown->Release();
        return hr;
    }

    // 查询COM组件的IDispatch接口
    IDispatch* pIDispatch = NULL;
    hr = pIUnknown->QueryInterface(IID_IDispatch, (void **)&pIDispatch);
    pIUnknown->Release();
    if (FAILED(hr)) {
        printf("Failed to get IDispatch interface. Error code: 0x%x", hr);
        pUnknown->Release();
        return hr;
    }

    // 准备yh_call函数的参数
    VARIANTARG args[4];
    VariantInit(&args[3]);
    args[3].vt = VT_BYREF | VT_BSTR;
    BSTR ls_out_data;
    args[3].pbstrVal = &ls_out_data;
    VariantInit(&args[2]);
    args[2].vt = VT_BYREF | VT_I4;
    long appcode = 0;
    args[2].plVal = &appcode;
    VariantInit(&args[1]);
    args[1].vt = VT_BYREF | VT_BSTR;
    BSTR appmsg;
    args[1].pbstrVal = &appmsg;
    VariantInit(&args[0]);
    args[0].vt = VT_BSTR;
    args[0].bstrVal = SysAllocString(L"input_data_string"); // 替换为实际的字符串

    // 构造yh_call函数的DISPPARAMS结构体
    DISPPARAMS dispparams = {args, NULL, 4, 0};

    // 调用yh_call函数
    VARIANT result;
    VariantInit(&result);
    EXCEPINFO excepinfo;
    hr = pIDispatch->Invoke(0x123, IID_NULL, LOCALE_SYSTEM_DEFAULT, DISPATCH_METHOD, &dispparams, &result, &excepinfo, NULL);
    if (FAILED(hr)) {
        printf("Failed to invoke yh_call function. Error code: 0x%x", hr);
        pIDispatch->Release();
        pUnknown->Release();
        return hr;
    }

    // 处理返回结果
    printf("appcode=%d, appmsg=%S, ls_out_data=%S", appcode, appmsg, ls_out_data);

    // 释放资源
    SysFreeString(appmsg);
    SysFreeString(ls_out_data);
    VariantClear(&result);
    pIDispatch->Release();
    pUnknown->Release();

    CoUninitialize();
    return 0;
}

需要注意的是，这段代码中的CLSID_Component需要替换为实际的COM组件的CLSID，而args[0].bstrVal需要替换为实际的输入数据字符串。同时，输出参数ls_out_data和appmsg需要在使用后调用SysFreeString()函数释放资源。