URLDownloadToCacheFile下载如何做进度显示? URLDownloadToCacheFile或者URLDownloadToFile这两个函数如何在下载时做进度条呀?在网上查了不少资料,是可以的,但是没有详细的东西,希望高手指点,希望不要光给一网址什么的。能给出简单示范的追分!另,我下载了一份urlfile的源码,是可以实现的,但是没看太懂,有没有更简单直观一点的? 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 URLDownloadToCacheFile或者URLDownloadToFile这两个函数调用的关键是要实现IBindStatusCallback接口。函数内部会调用IBindStatusCallback接口中的函数。其中重载IBindStatusCallback::OnProgress就可知道下载的进度,在这个函数内部实现你的进度条更新。一下是一个IBindStatusCallBack的封装例子,可参考一下http://www.utblog.com/plog/1/article/1203 class CBindCBHttpNego : public IBindStatusCallback, public IHttpNegotiate{public: DWORD m_cRef; CBindCBHttpNego() : m_cRef(1) {} virtual ~CBindCBHttpNego() {} // IBindStatusCallback methods. STDMETHOD(OnStartBinding)( /* [in] */ DWORD dwReserved, /* [in] */ IBinding __RPC_FAR *pib) { return E_NOTIMPL; } STDMETHOD(GetPriority)( /* [out] */ LONG __RPC_FAR *pnPriority) { return E_NOTIMPL; } STDMETHOD(OnLowResource)( /* [in] */ DWORD reserved) { return E_NOTIMPL; } STDMETHOD(OnProgress)( /* [in] */ ULONG ulProgress, /* [in] */ ULONG ulProgressMax, /* [in] */ ULONG ulStatusCode, /* [in] */ LPCWSTR wszStatusText) { return E_NOTIMPL; } //在这里实现进度条的更新 STDMETHOD(OnStopBinding)( /* [in] */ HRESULT hresult, /* [unique][in] */ LPCWSTR szError) { return E_NOTIMPL; } STDMETHOD(GetBindInfo)( /* [out] */ DWORD __RPC_FAR *grfBINDF, /* [unique][out][in] */ BINDINFO __RPC_FAR *pbindinfo) { return E_NOTIMPL; } STDMETHOD(OnDataAvailable)( /* [in] */ DWORD grfBSCF, /* [in] */ DWORD dwSize, /* [in] */ FORMATETC __RPC_FAR *pformatetc, /* [in] */ STGMEDIUM __RPC_FAR *pstgmed) { return E_NOTIMPL; } STDMETHOD(OnObjectAvailable)( /* [in] */ REFIID riid, /* [iid_is][in] */ IUnknown __RPC_FAR *punk) { return E_NOTIMPL; } // IHttpNegotiate methods STDMETHODIMP BeginningTransaction(/* [in] */ LPCWSTR szURL, /* [unique][in] */ LPCWSTR szHeaders, /* [in] */ DWORD dwReserved, /* [out] */ LPWSTR __RPC_FAR *pszAdditionalHeaders); STDMETHODIMP OnResponse(/* [in] */ DWORD dwResponseCode, /* [unique][in] */ LPCWSTR szResponseHeaders, /* [unique][in] */ LPCWSTR szRequestHeaders, /* [out] */ LPWSTR __RPC_FAR *pszAdditionalRequestHeaders) { return E_NOTIMPL; } // IUnknown methods. // @Note that IE never calls any of these methods, since the caller owns the IBindStatusCallback interface STDMETHOD_(ULONG,AddRef)() { return m_cRef++; } STDMETHOD_(ULONG,Release)() { if (--m_cRef == 0) { delete this; return 0; } return m_cRef; } STDMETHOD(QueryInterface)( /* [in] */ REFIID riid, /* [iid_is][out] */ void __RPC_FAR *__RPC_FAR *ppvObject) { *ppvObject = NULL; if (riid==IID_IUnknown || riid==IID_IBindStatusCallback) { *ppvObject = (IBindStatusCallback*)this; AddRef(); return S_OK; } else if (riid==IID_IHttpNegotiate) { *ppvObject = (IHttpNegotiate*)this; AddRef(); return S_OK; } else { return E_NOINTERFACE; } }}; 是不是要自己写一个类来继承IBindStatusCallback,然后重新实现CBSCallbackImpl的OnProgress方法呢? 为什么我写的类在实例化时就出错?error LNK2019: 无法解析的外部符号 "public: __thiscall CBSCallbackImpl::CBSCallbackImpl(void)" (??0CBSCallbackImpl@@QAE@XZ),该符号在函数 "public: static unsigned int __cdecl CXUpdateDlg::Download(void *)" (?Download@CXUpdateDlg@@SAIPAX@Z) 中被引用 如何使用SetWindowsThemes函数设置程序的主题外观 怎样把vc中的控件修改为Labview控件 vs2005编译后的程序,在其它机子上出现"应用程序配置不正确"问题 请问OnReceive()何时触发?既socket事件触发机制。。 本地端口和远程端口有什么区别? 问一个关于TCP的问题 窗口重画 如何去掉MDI中“窗口”菜单下的最近打开窗口项 help me 远程注入的dll1文件 怎么继续加载新的dll2? CSocketFile 和 CArchive 的使用 关于MFC ActiveX 中的简单问题。
函数内部会调用IBindStatusCallback接口中的函数。
其中重载IBindStatusCallback::OnProgress就可知道下载的进度,在这个函数内部实现你的进度条更新。一下是一个IBindStatusCallBack的封装例子,可参考一下
http://www.utblog.com/plog/1/article/1203
public:
DWORD m_cRef;
CBindCBHttpNego() : m_cRef(1) {} virtual ~CBindCBHttpNego() {} // IBindStatusCallback methods. STDMETHOD(OnStartBinding)(
/* [in] */ DWORD dwReserved,
/* [in] */ IBinding __RPC_FAR *pib)
{ return E_NOTIMPL; } STDMETHOD(GetPriority)(
/* [out] */ LONG __RPC_FAR *pnPriority)
{ return E_NOTIMPL; }
STDMETHOD(OnLowResource)(
/* [in] */ DWORD reserved)
{ return E_NOTIMPL; } STDMETHOD(OnProgress)(
/* [in] */ ULONG ulProgress,
/* [in] */ ULONG ulProgressMax,
/* [in] */ ULONG ulStatusCode,
/* [in] */ LPCWSTR wszStatusText)
{ return E_NOTIMPL; } //在这里实现进度条的更新 STDMETHOD(OnStopBinding)(
/* [in] */ HRESULT hresult,
/* [unique][in] */ LPCWSTR szError)
{ return E_NOTIMPL; } STDMETHOD(GetBindInfo)(
/* [out] */ DWORD __RPC_FAR *grfBINDF,
/* [unique][out][in] */ BINDINFO __RPC_FAR *pbindinfo)
{ return E_NOTIMPL; } STDMETHOD(OnDataAvailable)(
/* [in] */ DWORD grfBSCF,
/* [in] */ DWORD dwSize,
/* [in] */ FORMATETC __RPC_FAR *pformatetc,
/* [in] */ STGMEDIUM __RPC_FAR *pstgmed)
{ return E_NOTIMPL; } STDMETHOD(OnObjectAvailable)(
/* [in] */ REFIID riid,
/* [iid_is][in] */ IUnknown __RPC_FAR *punk)
{ return E_NOTIMPL; } // IHttpNegotiate methods STDMETHODIMP BeginningTransaction(/* [in] */ LPCWSTR szURL,
/* [unique][in] */ LPCWSTR szHeaders,
/* [in] */ DWORD dwReserved,
/* [out] */ LPWSTR __RPC_FAR *pszAdditionalHeaders); STDMETHODIMP OnResponse(/* [in] */ DWORD dwResponseCode,
/* [unique][in] */ LPCWSTR szResponseHeaders,
/* [unique][in] */ LPCWSTR szRequestHeaders,
/* [out] */ LPWSTR __RPC_FAR *pszAdditionalRequestHeaders)
{ return E_NOTIMPL; } // IUnknown methods. // @Note that IE never calls any of these methods, since the caller owns the IBindStatusCallback interface
STDMETHOD_(ULONG,AddRef)() { return m_cRef++; }
STDMETHOD_(ULONG,Release)() { if (--m_cRef == 0) { delete this; return 0; } return m_cRef; }
STDMETHOD(QueryInterface)(
/* [in] */ REFIID riid,
/* [iid_is][out] */ void __RPC_FAR *__RPC_FAR *ppvObject)
{
*ppvObject = NULL;
if (riid==IID_IUnknown || riid==IID_IBindStatusCallback)
{
*ppvObject = (IBindStatusCallback*)this;
AddRef();
return S_OK;
}
else if (riid==IID_IHttpNegotiate)
{
*ppvObject = (IHttpNegotiate*)this;
AddRef();
return S_OK;
}
else {
return E_NOINTERFACE;
}
}
};
然后重新实现CBSCallbackImpl的OnProgress方法呢?