HttpWebRequest &&FileStream分块读取和写入文件&WebClient

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//HttpWebRequest 下载文件

private void DownloadFile(string filePath)
{
string[] temp = filePath.Split(new string[] { @"/" }, StringSplitOptions.None);
string fileName = temp[temp.Length - 1];
string PhysicalFilePath = Request.PhysicalApplicationPath + ConfigurationManager.AppSettings["UploadFilePath"];
if (!Directory.Exists(PhysicalFilePath))
Directory.CreateDirectory(PhysicalFilePath);
if (!System.IO.File.Exists(PhysicalFilePath + "\\" + fileName))
{
Uri downUri = new Uri(@"http://192.168.1.1" + filePath);

HttpWebRequest hwr = (HttpWebRequest)WebRequest.Create(downUri);

//设置接收对象的范围为0-10000000字节。
hwr.AddRange(0, 10000000);
using (Stream stream = hwr.GetResponse().GetResponseStream())
{
//文件流，流信息读到文件流中，读完关闭
using (FileStream fs = System.IO.File.Create(PhysicalFilePath + "\\" + fileName))
{
//建立字节组，并设置它的大小是多少字节

byte[] bytes = new byte[10240];
int n = 1;
while (n > 0)
{
//一次从流中读多少字节，并把值赋给Ｎ，当读完后，Ｎ为０,并退出循环
n = stream.Read(bytes, 0, 10240);
fs.Write(bytes, 0, n);　//将指定字节的流信息写入文件流中
}
}
}
}
}

static public void HttpRemoteDownload2()
{
string URLAddress = "http://192.168.1.106/ttIP.txt";
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(URLAddress);
request.Method = "GET";
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
Stream responseStream = response.GetResponseStream();
List<byte> btlst = new List<byte>();
int b = responseStream.ReadByte();
while (b > -1)
{
btlst.Add((byte)b);
b = responseStream.ReadByte();
}

byte[] bts = btlst.ToArray();

File.WriteAllBytes("testDownload.txt", bts); // 保存文件
}

//FileStream分块读取和写入文件

static void Main(string[] args)

{

FileStream fsOutput = new FileStream("D:\\wwwrite.txt", FileMode.Create | FileMode.Append);
FileStream fs;
//获得文件所在路径
string filePath = "C:\\rrr.txt";

//打开文件
try
{
fs = new FileStream(filePath, FileMode.Open);
}
catch (Exception)
{
throw;
}
int chunkSize = 100;
//尚未读取的文件内容长度
long left = fs.Length;
//存储读取结果
byte[] bytes = new byte[chunkSize];

//读取位置
int start = 0;
//实际返回结果长度
int num = 0;
//当文件未读取长度大于0时，不断进行读取
while (left > 0)
{
fs.Position = start;
num = 0;
if (left < chunkSize)
{
bytes = new byte[left];
num = fs.Read(bytes, 0, Convert.ToInt32(left));
}
else
{
num = fs.Read(bytes, 0, chunkSize);
}


//开始写入
fsOutput.Write(bytes, 0, bytes.Length);
//清空缓冲区
fsOutput.Flush();

Array.Clear(bytes, 0, bytes.Length);
if (num == 0)
break;
start += num;
left -= num;
Console.WriteLine(Encoding.UTF8.GetString(bytes));
}

Console.ReadLine();
fs.Close();

fsOutput.Close();

}

//WebClient

static public void HttpRemoteDownload()
{
string URLAddress = "http://192.168.1.106/ttIP.txt";
WebClient client = new WebClient();
Stream str = client.OpenRead(URLAddress);
StreamReader reader = new StreamReader(str);
byte[] fileData = new byte[1000000];
int fileDataLength = (int)fileData.Length;
int startIndex = 0;

while (fileDataLength > 0)
{

int m = str.Read(fileData, startIndex, fileDataLength);
if (m == 0)
break;

startIndex += m;
fileDataLength -= m;
}

reader.Dispose();
str.Dispose();
string receivePath = @"C:\";
string path = receivePath + System.IO.Path.GetFileName(URLAddress);
FileStream fstr = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write);
fstr.Write(fileData, 0, startIndex);
fstr.Flush();
fstr.Close();
}

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