public class TestController : ApiController { public HttpResponseMessage GetImg() { //获取文件的绝对路径 string absolutePath = System.Web.Hosting.HostingEnvironment.MapPath("/img/woman.jpg"); System.IO.FileStream fs = new System.IO.FileStream(absolutePath, System.IO.FileMode.Open, System.IO.FileAccess.Read); HttpResponseMessage result = new HttpResponseMessage(HttpStatusCode.OK) { Content = new StreamContent(fs), }; result.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("image/jpg"); //下面这行代码表示,弹出下载框,由用户选择需要保存的位置 //如果不写,则直接打开该图片 result.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment") { //需要保存的图片的默认名字,如果不写,则默认提示为控制器名字,如本例为提示保存的名字为:"test" FileName = "newWoman.jpg" }; return result; } }