C#调用阿里云OSS上传文件(分片)

首先从阿里云官网下载OSS的.NET SDK，然后在项目中添加引用Aliyun.OSS.dll

本例为分片上传方式，适用于上传比较大的文件。

引入命名空间：

using Aliyun.OSS;
using Aliyun.OSS.Common;

定义阿里云OSS接口参数：

private string AccessKeyId = "xxx"; //阿里云AccessKeyId
private string AccessKeySecret = "xxx"; //阿里云AccessKeySecret
private string OssEndpoint = "http://oss-cn-xxx.aliyuncs.com"; //阿里云Endpoint
private string OssBucket = "xxx"; //阿里云Bucket
private static OssClient aliyunclient; //阿里云OSS连接对象
static int partSize = 50 * 1024 * 1024; //分片上传大小

创建阿里云OSS客户端连接：

aliyunclient = new OssClient(this.OssEndpoint, this.AccessKeyId, this.AccessKeySecret);

分片上传文件：

string remotefile = "path/to/aliyun/test.mp4"; //阿里云上目标文件
string localfile = "D:\test.mp4"; //要上传的本地文件
try
{
    var uploadId = InitiateMultipartUpload(this.OssBucket, remotefile);
    var partETags = UploadParts(this.OssBucket, remotefile, localfile, uploadId, partSize);
    CompleteUploadPart(this.OssBucket, remotefile, uploadId, partETags);
    bool doesexist = aliyunclient.DoesObjectExist(this.OssBucket, remotefile);
    if (doesexist)
    {
        this.logtext = "上传成功。";
    }
    else
    {
        this.logtext = "上传失败。";
    }
}
catch (OssException ex)
{
    this.logtext = "上传失败," + ex.Message + "。";
}

分片上传函数定义：

private static string InitiateMultipartUpload(String bucketName, String objectName)
{
    var request = new InitiateMultipartUploadRequest(bucketName, objectName);
    var result = aliyunclient.InitiateMultipartUpload(request);
    return result.UploadId;
}
 
private static List<PartETag> UploadParts(String bucketName, String objectName, String fileToUpload, String uploadId, int partSize)
{
    var fi = new FileInfo(fileToUpload);
    var fileSize = fi.Length;
    var partCount = fileSize / partSize;
    if (fileSize % partSize != 0)
    {
        partCount++;
    }
 
    var partETags = new List<PartETag>();
    using (var fs = File.Open(fileToUpload, FileMode.Open))
    {
        for (var i = 0; i < partCount; i++)
        {
            var skipBytes = (long)partSize * i;
            fs.Seek(skipBytes, 0);
            var size = (partSize < fileSize - skipBytes) ? partSize : (fileSize - skipBytes);
            var request = new UploadPartRequest(bucketName, objectName, uploadId)
            {
                InputStream = fs,
                PartSize = size,
                PartNumber = i + 1
            };
 
            var result = aliyunclient.UploadPart(request);
 
            partETags.Add(result.PartETag);
        }
    }
    return partETags;
}
 
private static CompleteMultipartUploadResult CompleteUploadPart(String bucketName, String objectName, String uploadId, List<PartETag> partETags)
{
    var completeMultipartUploadRequest =
        new CompleteMultipartUploadRequest(bucketName, objectName, uploadId);
    foreach (var partETag in partETags)
    {
        completeMultipartUploadRequest.PartETags.Add(partETag);
    }
 
    return aliyunclient.CompleteMultipartUpload(completeMultipartUploadRequest);
}

注意事项：

阿里云上目标文件路径开头不能是“/”