unity3d 关于断点下载和整个下载(用于更新)

转自：http://blog.csdn.net/yutyliu/article/details/24346459

string t = "";

//整体下载

IEnumerator downfile(string url, string LocalPath,UILabel DesLable)
{
Uri u = new Uri(url);
HttpWebRequest mRequest = (HttpWebRequest)WebRequest.Create(u);
mRequest.Method = "GET";
mRequest.ContentType = "application/x-www-form-urlencoded";

HttpWebResponse wr = (HttpWebResponse)mRequest.GetResponse();

Stream sIn = wr.GetResponseStream();
FileStream fs = new FileStream(LocalPath, FileMode.Create, FileAccess.Write);

long length = wr.ContentLength;
long i = 0;
decimal j = 0;

while (i < length)
{
byte[] buffer = new byte[1024];
i += sIn.Read(buffer, 0, buffer.Length);
fs.Write(buffer, 0, buffer.Length);

if ((i % 1024) == 0)
{
j = Math.Round(Convert.ToDecimal((Convert.ToDouble(i) / Convert.ToDouble(length)) * 100), 4);
t= "当前下载文件大小:" + length.ToString() + "字节 当前下载大小:" + i + "字节 下载进度" + j.ToString() + "%";
DesLable.text=t.ToString();
}
else
{
t = "当前下载文件大小:" + length.ToString() + "字节 当前下载大小:" + i + "字节";
DesLable.text=t.ToString();
}

yield return false;

}

sIn.Close();
wr.Close();
fs.Close();

}

string downloadString="已经下载";

//断点下载
IEnumerator FPointDown(string uri,string saveFile,UILabel DesLable,UISprite LoadSprite)
{
//打开网络连接
System.Net.HttpWebRequest request = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(uri);
System.Net.HttpWebRequest requestGetCount = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(uri);
long countLength = requestGetCount.GetResponse().ContentLength;

//打开上次下载的文件或新建文件
long lStartPos = 0;
System.IO.FileStream fs;
if (System.IO.File.Exists(saveFile))
{
fs = System.IO.File.OpenWrite(saveFile);
lStartPos = fs.Length;
if (countLength - lStartPos <= 0)
{
fs.Close();
t = "已经";
DesLable.text=t.ToString();
yield break;
}
fs.Seek(lStartPos, System.IO.SeekOrigin.Current); //移动文件流中的当前指针
}
else
{
fs = new System.IO.FileStream(saveFile, System.IO.FileMode.Create);
}

if (lStartPos > 0)
{
request.AddRange((int)lStartPos); //设置Range值
print(lStartPos);
}

//向服务器请求，获得服务器回应数据流
System.IO.Stream ns = request.GetResponse().GetResponseStream();
int len = 1024 * 8;

byte[] nbytes = new byte[len];
int nReadSize = 0;
nReadSize = ns.Read(nbytes, 0, len);
while (nReadSize > 0)
{
fs.Write(nbytes, 0, nReadSize);
nReadSize = ns.Read(nbytes, 0, len);
t = downloadString+" : " + fs.Length / 1024 + "kb /" + countLength / 1024 + "kb"+" ---- "+((double)fs.Length/countLength).ToString()+"%";

yield return false;
}
ns.Close();
fs.Close();
//这里放更新安装代码,或者可以测试这个下载的包有没有出错,验证sha和md5