如何显示图像 <img> 从数据库中存储为基础64 Stirng？

Question

I have stored image files in format base64String in database and need to render that image in a html <img> tag.

How do I do it?

Answer 1

1. Add a GenericHandler to your web site named DBImage.ashx
2. Your img src attributes should point to something like DBImage.ashx?key=[dbkey]

3. In the generic handler's ProcessRequest you will
   a) retrieve the base64 string from the database based on the query string dbkey

   b) convert the base64 to a byte array using Convert.FromBase64String()

   c) set the response content type to the appropriate mime type (like image/jpeg)

   d) write the byte array to the response stream

That should do it.

Answer 2

You can use base64 string directly to display image without any kind of conversion

<img src="data:image/png;base64,iVBORw0KGgoAAAANS..." />

make sure your base64 string have data:image/png;base64

if not try this function to simply append it

public string GetImageSrc(string base64Src)
{
   return "data:image/png;base64," + base64Src;
}

Demo : http://jsfiddle.net/casiano/xadvz/

Answer 3

Try this:

  byte[] imageBytes = Convert.FromBase64String(base64String);
  MemoryStream ms = new MemoryStream(imageBytes, 0, 
    imageBytes.Length);
  ms.Write(imageBytes, 0, imageBytes.Length);
  Image image = Image.FromStream(ms, true);

Answer 4

May be this would help you

 public Image Base64ToImage(string base64String)
 {
    // Convert Base64 String to byte[]
    byte[] imageBytes = Convert.FromBase64String(base64String);
    // Convert byte[] to Image
    using (var ms = new MemoryStream(imageBytes, 0, imageBytes.Length))
    {
        Image image = Image.FromStream(ms, true);
        return image;
    }
 }

after that you can easily call Image.Save(filePath); to save the image and call that image to your HTML.