Core 简单实现七牛图片上传（FormData 和 Base64）
七牛图片上传 SDK（.NET 版本）：/kodo/sdk/1237/csharp
UpoladService示例代码：
public class UpoladService : IUpoladService{private readonly static string[] _imageExtensions = new string[] { ".jpg", ".png", ".gif", ".jpeg", ".bmp" };private AppSettings _appSettings;public UpoladService(IOptions<AppSettings> appSettings){_appSettings = appSettings.Value;}public async Task<SubmitResult> UploadStream(Stream stream, string fileName, AppType appType){if (stream == null){return SubmitResult.Fail("图片为null");}if (string.IsNullOrWhiteSpace(fileName)){return SubmitResult.Fail("图片名称为空");}try{var extensionName = fileName.Substring(fileName.LastIndexOf("."));if (!_imageExtensions.Contains(extensionName.ToLower())){return SubmitResult.Fail("图片格式有误");}var generateFileName = $"{DateTime.Now.ToString("yyyyMMddHHmmssfff-")}{Guid.NewGuid().GetHashCode().ToString().Replace("-", string.Empty)}{extensionName}";var saveKey = $"wl/{appType.ToString().ToLower()}/{generateFileName}";// 生成(上传)凭证时需要使用此Mac// 这个示例单独使用了一个Settings类，其中包含AccessKey和SecretKey// 实际应用中，请自行设置您的AccessKey和SecretKeyMac mac = new Mac(_appSettings.AccessKey, _appSettings.SecretKey);// 上传策略，参见 // /kodo/manual/put-policyPutPolicy putPolicy = new PutPolicy();// 如果需要设置为"覆盖"上传(如果云端已有同名文件则覆盖)，请使用 SCOPE = "BUCKET:KEY"// putPolicy.Scope = bucket + ":" + saveKey;putPolicy.Scope = _appSettings.Bucket;// 上传策略有效期(对应于生成的凭证的有效期) putPolicy.SetExpires(3600);// 上传到云端多少天后自动删除该文件，如果不设置（即保持默认默认）则不删除//putPolicy.DeleteAfterDays = 1;// 生成上传凭证，参见// /kodo/manual/upload-token string jstr = putPolicy.ToJsonString();string token = Auth.CreateUploadToken(mac, jstr);FormUploader fu = new FormUploader();var result = await fu.UploadStreamAsync(stream, saveKey, token);if (result.Code == 200){return SubmitResult.Success($"{_appSettings.Domain}/{saveKey}");}return SubmitResult.Fail("上传失败");}catch (Exception ex){return SubmitResult.Fail($"上传失败：{ex.Message}");}}}
UploadController示例代码：
[EnableCors("default")][Route("upload")]public class UploadController : WebApiController{private IUpoladService _upoladService;public UploadController(IUpoladService upoladService){_upoladService = upoladService;}[Route("{appType}/stream")][HttpPost]public async Task<IActionResult> UploadByStream(AppType appType){if (Request.Form.Files.Count == 0){return Fail("图片不存在");}var file = Request.Form.Files[0];var result = await _upoladService.UploadStream(file.OpenReadStream(), file.FileName, appType);if (result.IsSuccess){return Ok(new { pic_url = result.Data, is_success = true });}return Fail(result.Message);}[Route("{appType}/base64")][HttpPost]public async Task<IActionResult> UploadByBase64([FromBody]JObject data, AppType appType){var imageBase64 = data["image_base64"].ToObject<string>();var fileName = data["file_name"].ToObject<string>();if (!string.IsNullOrWhiteSpace(imageBase64)){var reg = new Regex("data:image/(.*);base64,");imageBase64 = reg.Replace(imageBase64, "");byte[] imageByte = Convert.FromBase64String(imageBase64);var stream = new MemoryStream(imageByte);var result = await _upoladService.UploadStream(stream, fileName, appType);if (result.IsSuccess){return Ok(new { pic_url = result.Data, is_success = true });}return Fail(result.Message);}return Json(new { success = false, result = "请选择文件！" });}}
JS 上传图片示例代码：
<form method="post" enctype="multipart/form-data"><input type="file" id="files"name="files" multiple /><input type="button"id="uploadStream"value="Upload Selected Files" /><input type="button"id="uploadBase64"value="Upload Selected Files" /></form><script>$(document).ready(function () {$("#upload").click(function (evt) {var fileUpload = $("#files").get(0);var files = fileUpload.files;var data = new FormData();for (var i = 0; i < files.length; i++) {data.append(files[i].name, files[i]);}$.ajax({type: "POST",url: "http://localhost:5002/upload/avatar/stream",processData: false,contentType: false,data: data,success: function (data) {if (data.is_success) {console.log(data.pic);}else {console.log(data.msg);}console.log(data);},error: function () {console.log("There was error uploading files!");}});});$("#uploadBase64").click(function (evt) {var fileUpload = $("#files").get(0);var files = fileUpload.files;var data = {};//生成base64var reader = new FileReader();reader.readAsDataURL(files[0]);reader.onload = function () {data.image_base64 = reader.result;data.file_name = files[0].name;$.ajax({type: "POST",url: "http://localhost:5002/upload/avatar/base64",contentType: 'application/json; charset=utf-8',data: JSON.stringify(data),dataType: 'json',success: function (data) {if (data.is_success) {console.log(data.pic);}else {console.log(data.msg);}console.log(data);},error: function () {console.log("There was error uploading files!");}});return reader.result;};reader.onerror = function (error) {console.log('Error: ', error);};});});</script>
