Dropzone.js

Question

我有以下放置区来显示存储在 app_data 文件夹中的图像，但缩略图不起作用，因为 app_data 文件夹仅限网络用户使用。

在控制台中我得到：

"NetworkError: 404 Not Found - http://localhost:61372/app_data/wallimages/dropzonelayout.png"

我特意将图像存储在 app_data 文件夹中以限制访问，只有具有特定角色的用户才能编辑上传的文件，即删除等。所以我的问题是如何在这种情况下显示缩略图用于编辑上传的文件。我不想使用一些默认图像，因为我已经知道如果我想将文件存储在 app_data 文件夹中，这可能是另一种解决方案。

有什么建议吗？

Dropzone.options.dropzoneForm = {
        acceptedFiles: "image/*",
        init: function () {
            var thisDropzone = this;


            $.getJSON("/home/GetAttachments/").done(function (data) {
                if (data.Data != '') {

                    $.each(data.Data, function (index, item) {
                            //// Create the mock file:
                            var mockFile = {
                                name: item.AttachmentID,
                                size: 12345
                            };

                            console.log(mockFile);
                            // Call the default addedfile event handler
                            thisDropzone.emit("addedfile", mockFile);

                            // And optionally show the thumbnail of the file:
                            thisDropzone.emit("thumbnail", mockFile, item.Path);

                            // If you use the maxFiles option, make sure you adjust it to the
                            // correct amount:
                            //var existingFileCount = 1; // The number of files already uploaded
                            //myDropzone.options.maxFiles = myDropzone.options.maxFiles - existingFileCount;
                    });
                }

            });




        }


    };

这是获取图像的操作：

 public ActionResult GetAttachments()
    {
        //Get the images list from repository
        var attachmentsList =  new List<AttachmentsModel>
        {
            new AttachmentsModel {AttachmentID = 1, FileName = "dropzonelayout.png", Path = "/app_data/wallimages/dropzonelayout.png"},
            new AttachmentsModel {AttachmentID = 2, FileName = "imageslider-3.png", Path = "/app_data/wallimages/imageslider-3.png"}
        }.ToList();

        return Json(new { Data = attachmentsList }, JsonRequestBehavior.AllowGet); 
    }

Answer 1

您将需要一个将流式传输图像的控制器操作：

public class ImagesController : Controller
{
    [Authorize] // <!-- You probably want only authenticated users to access this
    public ActionResult Thumbnail(string imageName)
    {
        // TODO: your authorization stuff comes here
        // Verify that the currently authenticated user has the required
        // permissions to access the requested image
        // It is also very important to properly sanitize the imageName
        // parameter to avoid requests such as imageName=../../../super_secret.png

        var path = Server.MapPath("~/App_Data/" + imageName);

        return base.File(path, "image/png");
    }
}

现在您可以从客户端使用此 /images/thumbnail?imagename=my_thumbnail.png 操作：

var attachmentsList =  new List<AttachmentsModel>
{
    new AttachmentsModel 
    {
        AttachmentID = 1, 
        FileName = "dropzonelayout.png", 
        Path = Url.Action("thumbnail", "images", new { imagename = "dropzonelayout.png" })
    },
    new AttachmentsModel 
    {
        AttachmentID = 2, 
        FileName = "imageslider-3.png", 
        Path = Url.Action("thumbnail", "images", new { imagename = "imageslider-3.png" })
    }
}.ToList();

Dropzone.js - 显示存储在 app_data 文件夹中的图像

Dropzone.js - display images stored in app_data folder

javascript

asp.net-mvc

image-upload