在ASP.NET MVC中通过JQuery AJAX实现文件上传

<input type="file" id="fileInput" />
<button id="uploadButton">上传</button>

$('#uploadButton').click(function() {
  var file = $('#fileInput').get(0).files[0];
  if (file) {
    uploadFile(file);
  }
});

function uploadFile(file) {
  var formData = new FormData();
  formData.append('file', file);

  $.ajax({
    url: '/Upload/UploadFile',
    type: 'POST',
    data: formData,
    processData: false,
    contentType: false,
    success: function(response) {
      // 文件上传成功后的处理逻辑
    },
    error: function(xhr, status, error) {
      // 文件上传失败后的处理逻辑
    }
  });
}

public class UploadController : Controller
{
    [HttpPost]
    public ActionResult UploadFile(HttpPostedFileBase file)
    {
        if (file != null && file.ContentLength > 0)
        {
            // 处理文件上传逻辑
            var fileName = Path.GetFileName(file.FileName);
            var filePath = Path.Combine(Server.MapPath("~/Uploads"), fileName);
            file.SaveAs(filePath);
            return Json(new { success = true, message = "文件上传成功" });
        }
        else
        {
            return Json(new { success = false, message = "请选择要上传的文件" });
        }
    }
}