Saving a base64 string as an image into a folder on server using C# and Web Api

问题

I am posting a Base64 string via Ajax to my Web Api controller. Code below

Code for converting string to Image

public static Image Base64ToImage(string base64String)
{
    // Convert base 64 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;
    }
}

Controller Code

public bool SaveImage(string ImgStr, string ImgName)
{
    Image image = SAWHelpers.Base64ToImage(ImgStr);
    String path = HttpContext.Current.Server.MapPath("~/ImageStorage"); //Path

    //Check if directory exist
    if (!System.IO.Directory.Exists(path))
    {
        System.IO.Directory.CreateDirectory(path); //Create directory if it doesn't exist
    }

    string imageName = ImgName + ".jpg";

    //set the image path
    string imgPath = Path.Combine(path, imageName);

    image.Save(imgPath, System.Drawing.Imaging.ImageFormat.Jpeg);

    return true;
}

This is always failing with a generic GDI+ error. What am I missing ? Is there a better way to save a specific string as an image on a folder ?

回答1:

In Base64 string You have all bytes of image. You don't need create Image object. All what you need is decode from Base64 and save this bytes as file.

Example

public bool SaveImage(string ImgStr, string ImgName)
{       
    String path = HttpContext.Current.Server.MapPath("~/ImageStorage"); //Path

    //Check if directory exist
    if (!System.IO.Directory.Exists(path))
    {
        System.IO.Directory.CreateDirectory(path); //Create directory if it doesn't exist
    }

    string imageName = ImgName + ".jpg";

    //set the image path
    string imgPath = Path.Combine(path, imageName);

    byte[] imageBytes = Convert.FromBase64String(ImgStr);

    File.WriteAllBytes(imgPath, imageBytes);

    return true;
}

回答2:

In asp net core you can get the path from IHostingEnvironment

public YourController(IHostingEnvironment env)
{
   _env = env;
}

And the method,

public void SaveImage(string base64img, string outputImgFilename = "image.jpg")
{
   var folderPath = System.IO.Path.Combine(_env.ContentRootPath, "imgs");
   if (!System.IO.Directory.Exists(folderPath))
   {
      System.IO.Directory.CreateDirectory(folderPath);
   }
   System.IO.File.WriteAllBytes(Path.Combine(folderPath, outputImgFilename), Convert.FromBase64String(base64img));
}

来源：https://stackoverflow.com/questions/39394129/saving-a-base64-string-as-an-image-into-a-folder-on-server-using-c-sharp-and-web

标签

asp.net-web-api