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URLDownloadToFile
简介
指从指定URL地址读取内容并将读取到的内容保存到特定的档案里，下面列举了几种常见程式语言的实现方法。
Delphi
⒈uses UrlMon;
⒉//-------------------------------------------------------------------------------
⒊functionDownloadFile(SourceFile, DestFile: string): Boolean;
⒋// 参数 下载档案路径, 保存档案路径
⒌// 返回 下载结果
⒍ begin
⒎ try
⒏ Result := UrlDownloadToFile(nil, PChar(SourceFile), PChar(DestFile), 0, nil) = 0;
⒐ except
⒑ Result := False;
⒒ end;
⒓ end;
函式调用：
⒈var
⒉ url,destFile:string;
⒊url := 'http****filename.rar'
⒋destFile := 'E:\filename.rar'
⒌ifDownloadFile(url, DestFile)then
⒍ begin
⒎ ShowMessage('保存成功！');
⒏ end
⒐ else
⒑ begin
⒒ ShowMessage('保存不成功！');
⒓ end;
C++
Syntax:
HRESULT URLDownloadToFile( LPUNKNOWN pCaller, LPCTSTR szURL, LPCTSTR szFileName, DWORD dwReserved, LPBINDSTATUSCALLBACK lpfnCB);
Parameters:
pCallerPointer to the controlling IUnknown interface of the calling Microsoft ActiveX component (if the caller is an ActiveX component). //控制项的接口,如果不是控制项则为0.
szURL
Pointer to a string value containing the URL to be downloaded. Cannot be set to NULL
//要下载的url地址,不能为空.
szFileName
Pointer to a string value containing the name of the file to create for bits that come from the download.
//下载后保存的档案名称.
dwReserved
Reserved. Must be set to 0.
//保留栏位,必需为0
lpfnCB
Pointer to the caller's IBindStatusCallback interface. URLDownloadToFile calls this interface's IBindStatusCallback::OnProgress method on a connection activity, including the arrival of data. IBindStatusCallback::OnDataAvailable is never called.
//下载进度状态回调
Return Value
Returns one of the following values.
S_OK : The download started successfully.
E_OUTOFMEMORY: The buffer length is invalid, or there is insufficient memory to complete the operation.
INET_E_DOWNLOAD_FAILURE:The specified resource or callback interface was invalid.
Example:
#include "stdafx.h"#include <iostream>#include <UrlMon.h>#pragma comment(lib, "urlmon.lib") using namespace std;int _tmain(int argc, _TCHAR* argv[]){ HRESULT hr = URLDownloadToFile(0,_T("***ui.the9.**/wshell/WShell.exe"), _T ("D:\\WShell.exe"), 0,NULL); if (hr== S_OK) { cout<< "ok"<< endl; } return 0;}vb
该函式是VB的一个用来调用API进行网路下载的函式，过程如下：
后台下载
声明：
Private Declare Function URLDownloadToFile Lib "urlmon" Alias "URLDownloadToFileA" (ByVal pCaller As Long, ByVal szURL As String, ByVal szFileName As String, ByVal dwReserved As Long, ByVal lpfnCB As Long) As Long
'//调用
然后在代码里直接调用：
Call URLDownloadToFile(0, "网页地址", "保存到本地档案名称和地址", 0, 0)
如
Call URLDownloadToFile(0, "*****.baidu**/", "c:\1.htm", 0, 0)
相当于另外储存为
声明：
Private Declare Function DoFileDownload Lib "shdocvw.dll"(ByVal lpszFile As String) As Long
'//调用
然后在代码里直接调用：
Dim gourl As String
gourl = StrConv("网页地址", vbUnicode)
Call DoFileDownload(gourl)