如何上传使用ASP.net MVC4实体框架/显示图像 [英] How to upload/display images using ASP.net MVC4 with Entity Framework

问题描述

我有一个数据模型，像这样

I have a data model like so

    public class NewsItem
{
    public virtual int Id { get; set; }
    public virtual string NewsTitle { get; set; }
    public virtual string NewsContent { get; set; }
    public virtual byte[] NewsImage { get; set; }
    public virtual DateTime DateAdded { get; set; }
    public virtual bool IsLive { get; set; }
}

我再通过像这样一个视图中显示这样的数据：

I then display this data through a View like so:

@model BusinessObject.Domain.NewsItem
<div class="row-fluid">
    <h3>
        @Html.ValueFor(model => model.NewsTitle)
    </h3>
    <div class="span5">
    <img src="~/Content/images/stock.jpg" />
    </div>

<div class="span7">
<p>
    @Html.ValueFor(model => model.DateAdded)
</p>
<p>
    @Html.ValueFor(model => model.NewsContent)
</p>
</div>
 </div>

然后我在我的控制器节约使用_db.SaveChanges（）中的数据，像这样：

I then save the data using the _db.SaveChanges() in my controller like so:

[Authorize]
    [HttpPost]
    public ActionResult Create(CreateNewsViewModel input)
    {
        if (ModelState.IsValid)
        {
            var news = new NewsItem();
            news.NewsTitle = input.nTitle;
            news.NewsContent = input.nContent;
            news.DateAdded = input.nDateAdded;
            news.IsLive = input.nIsLive;
            Mydb data = new Mydb();
            data.NewsItems.Add(news);
            data.SaveChanges();
            return View("Index", data.NewsItems);

        }
        else
        {
            return View(input);
        }
    }

目前我没有图片上传位。我会如何呢？在我的分贝我有一个二进制字段，并在我的对象我的数据类型是一个byte []。但我不知道我需要处理图像上载？

Currently I don't have an image upload bit. How would I go about this? In my db I have a binary field, and my data type in my object is a byte[]. But I don't know where I need to handle the Image Upload?

我是否需要返回视图的单独行动？这方面的一些三分球将是盛大的。

Do I need a seperate action that returns the view? Some pointers on this would be grand.

干杯

推荐答案

您会希望类型的文件输入字段从视图和WebImage的一个实例来处理上传的图片上传：

You'll want an input field of type file to upload from the View and an instance of the WebImage to handle the uploaded image:

查看：

<input type="file" name="image" />

控制器：

WebImage image = WebImage.GetImageFromRequest();
byte[] toPutInDb = WebImage.GetBytes();

// ... put the byte array into the database

要显示从数据库中的图像，你会想检索从数据库中的字节数组，并返回一个FileAction控制器动作。您可以通过在ByteArray的另一个实例例如WebImage从数据库中检索得到这个图像（图像检索控制器动作）：

To display the images from your database, you will want a controller Action that retrieves the byte array from your database and returns a FileAction. You can get this image (for the image retrieving controller action) by instantiating another WebImage instance on the bytearray you retrieve from database:

WebImage image = new WebImage(byteArrayFromDb);

File(image.GetBytes(), "image/" + image.ImageFormat, image.FileName);

这篇关于如何上传使用ASP.net MVC4实体框架/显示图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！