​​C# 跳转新页面​​

​​判断URL文件是不是在于在。​​

​​C# 指定物理目录下载文件,Response.End导致“正在中止线程”异常的问题​​

 

public class FileHandler
{
public static bool DownLoadFile(string path, string fileName)
{
bool result = false;
if (!string.IsNullOrEmpty(path))
{
if (path.StartsWith("http") || path.StartsWith("https"))
{
result = InternetDownload(path, fileName);
}
else
{
result = LocalDownload(path, fileName);
}
}
return result;
}

private static bool LocalDownload(string path, string fileName)
{
bool result = false;
//Physical path "D:\InvoicePDF\"
string filePath = path + fileName;
if (File.Exists(filePath))
{
result = true;
}
else
{
try
{
//Relative path "~/InvoicePDF/"
filePath = HttpContext.Current.Server.MapPath(filePath);
if (File.Exists(filePath))
{
result = true;
}
}
catch
{
result = false;
}
}
if (result)
{
try
{
//string filePath = HttpContext.Current.Server.MapPath(path + fileName);
FileInfo fileInfo = new FileInfo(filePath);
HttpContext.Current.Response.Clear();
HttpContext.Current.Response.ClearContent();
HttpContext.Current.Response.ClearHeaders();
HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
HttpContext.Current.Response.AddHeader("Content-Length", fileInfo.Length.ToString());
HttpContext.Current.Response.AddHeader("Content-Transfer-Encoding", "binary");
HttpContext.Current.Response.ContentType = "application/octet-stream";
HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("utf-8");
HttpContext.Current.Response.WriteFile(fileInfo.FullName);
HttpContext.Current.Response.Flush();
}
catch (Exception e)
{
}
finally
{
HttpContext.Current.Response.End();
}
}
return result;
}

private static bool InternetDownload(string path, string fileName)
{
string url = path + fileName;
if (UrlIsExist(url))
{
ResponseRedirect.Redirect(HttpContext.Current.Response, url, "_blank", "");
//System.Web.HttpContext.Current.Response.Redirect(url,false);
}
return false;//Never use default behavior
}

private static bool UrlIsExist(string url)
{
System.Uri u = null;
try
{
u = new Uri(url);
}
catch { return false; }
bool isExist = false;
System.Net.HttpWebRequest r = System.Net.HttpWebRequest.Create(u) as System.Net.HttpWebRequest;
r.Method = "HEAD";
try
{
System.Net.HttpWebResponse s = r.GetResponse() as System.Net.HttpWebResponse;
if (s.StatusCode == System.Net.HttpStatusCode.OK)
{
isExist = true;
}
}
catch (System.Net.WebException x)
{
try
{
isExist = ((x.Response as System.Net.HttpWebResponse).StatusCode != System.Net.HttpStatusCode.NotFound);
}
catch { isExist = (x.Status == System.Net.WebExceptionStatus.Success); }
}
return isExist;
}
}