文件上传

一、控制器

[HttpPost]public IActionResult Edit(StudentEditViewModel model){//检查提供的数据是否有效，如果没有通过验证，需要重新编辑学生信息// 这样用户就可以更正并重新提交编辑表单if (ModelState.IsValid){Student student = _studentRepository.GetStudent(model.Id);student.Email = model.Email;student.Name = model.Name;student.ClassName = model.ClassName;if (model.Photos.Count > 0){if (model.ExistingPhotoPath != null){string filePath = bine(webHostEnvironment.WebRootPath, "images", model.ExistingPhotoPath);System.IO.File.Delete(filePath);}student.PhotoPath = ProcessUploadedFile(model);}Student updateStudent = _studentRepository.Update(student);return RedirectToAction("Index");}return View();}/// <summary>/// 将照片保存到指定的路径中，并返回唯一的文件名/// </summary>/// <returns></returns>private string ProcessUploadedFile(StudentCreateViewModel model){string uniqueFileName = null;if (model.Photos.Count > 0){foreach (var photo in model.Photos){//必须将图像上传到wwwwroot中的images文件夹//而要获取wwwroot文件夹的路径，我们需要注入 Core提供的IWebHostEnvironment//通过IWebHostEnvironment服务去获取wwwroot文件夹的路径string unloadsFolder = bine(webHostEnvironment.WebRootPath, "images");// 为了确保文件名是唯一的，我们在文件名后附加一个新的GUID值和一个下划线uniqueFileName = Guid.NewGuid().ToString() + "_" + photo.FileName;//路径string filePath = bine(unloadsFolder, uniqueFileName);//因为使用了非托管资源，所以需要手动进行释放using (var fileStream = new FileStream(filePath, FileMode.Create)){//复制到指定位置photo.CopyTo(fileStream);}}}return uniqueFileName;}

二、Model

1.类

代码如下（示例）：

public class StudentEditViewModel:StudentCreateViewModel{public int Id {get; set; }public string ExistingPhotoPath {get; set; }}public class StudentCreateViewModel{[Display(Name = "名字")][Required(ErrorMessage = "请输入名字"), MaxLength(50, ErrorMessage = "名字的长度不能超过50个字符")]public string Name {get; set; }[Required][Display(Name = "班级信息")]public ClassNameEnum? ClassName {get; set; }[Required(ErrorMessage = "请输入邮箱地址")][Display(Name = "邮箱地址")][RegularExpression(@"^[a-zA-Z0-9_.-]+@[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)*\.[a-zA-Z0-9]{2,6}$",ErrorMessage = "邮箱的格式不正确")]public string Email {get; set; }[Display(Name="图片")]public List<IFormFile> Photos {get; set; }}

2.视图

代码如下（示例）：

@model StudentEditViewModel@{ViewBag.Title = "编辑学生信息";//获取当前学生照片信息路径var photoPath = "~/images/" + (Model.ExistingPhotoPath ?? "1.jpg");}<form enctype="multipart/form-data" asp-controller="home" asp-action="edit" method="post" class="mt-3"><div asp-validation-summary="All" class="text-danger"></div><input hidden asp-for="Id" /><input hidden asp-for="ExistingPhotoPath" /><div class="form-group row"><label asp-for="Name" class="col-sm-2 col-form-label"></label><div class="col-sm-10"><input asp-for="Name" class="form-control" placeholder="请输入名字" /><span asp-validation-for="Name" class="text-danger"></span></div></div><div class="form-group row"><label asp-for="Email" class="col-sm-2 col-form-label"></label><div class="col-sm-10"><input asp-for="Email" class="form-control" placeholder="请输入邮箱" /><span asp-validation-for="Email" class="text-danger"></span></div></div><div class="form-group row"><label asp-for="ClassName" class="col-sm-2 col-form-label"></label><div class="col-sm-10"><select asp-for="ClassName" asp-items="Html.GetEnumSelectList<ClassNameEnum>()" class="custom-select mr-sm-2"><option value="">请选择</option></select><span asp-validation-for="ClassName" class="text-danger"></span></div></div><div class="form-group row"><label asp-for="Photos" class="col-sm-2 col-form-label"></label><div class="col-sm-10"><div class="custom-file"><input asp-for="Photos" multiple class="form-control custom-file-input" /><label class="custom-file-label">请选择照片......</label></div></div></div> <div class="form-group row col-sm-4 offset-4"><img class="imagesThumbnail" src="@photoPath" asp-append-version="true" /></div><div class="form-group row"><div class="col-sm-10"><button type="submit" class="btn btn-primary">更新</button><a asp-action="index" asp-controller="home" class="btn btn-primary">取消</a></div></div> @section Scripts{<script type="text/javascript">$(document).ready(function () {$('.custom-file-input').on("change", function () {console.log($(this))//var fileName = $(this).val().split("\\").pop();//$(this).next(".custom-file-label").html(fileName);var fileLable = $(this).next(".custom-file-label");var files = $(this)[0].files;if (files.length > 1) {fileLable.html("您已经选择了" + files.length + "个文件");} else {fileLable.html(files[0].name);}});})</script>}</form>

总结

HttpGet没有写出来，多张图片上传