Send Image From Controller To View In MVC3

问题:

I am using asp.net mvc3. I am making a bitmap using text by system.drawing. I want
to send that image from my controller to my view in VIEWDATA, but in my view I cannot parse VIEWDATA properly.

This is the controller code:

 public ActionResult About( string agha)
        {
            agha = "asgdjhagsdjgajdga";
             Color BackColor = Color.White;
            String FontName = "Times New Roman";
            int FontSize = 25;
            int Height = 50;
            int Width = 700;

            Bitmap bitmap = new Bitmap(Width, Height);
            Graphics graphics = Graphics.FromImage(bitmap);
            Color color = Color.Gray; ;
            Font font = new Font(FontName, FontSize);         

            SolidBrush BrushBackColor = new SolidBrush(BackColor);
            Pen BorderPen = new Pen(color);

            Rectangle displayRectangle = new Rectangle(new Point(0, 0), new Size(Width - 1, Height - 1));

            graphics.FillRectangle(BrushBackColor, displayRectangle);
            graphics.DrawRectangle(BorderPen, displayRectangle);               

            graphics.DrawString(agha,font,Brushes.Red, 0, 0);
            ViewData["picture"] = bitmap;            

            return View( );
        }

The view calling the viewdata looks like this

 <img src="@ViewData["picture"]." />

回答1:

I'd recommend you writing a custom action result to avoid polluting your controller action with completely useless and boring GDI+ infrastructure code:

public class ImageResult : ActionResult
{
    private readonly string _agha;
    public ImageResult(string agha)
    {
        _agha = agha;
    }

    public override void ExecuteResult(ControllerContext context)
    {
        Color BackColor = Color.White;
        String FontName = "Times New Roman";
        int FontSize = 25;
        int Height = 50;
        int Width = 700;

        using (Bitmap bitmap = new Bitmap(Width, Height))
        using (Graphics graphics = Graphics.FromImage(bitmap))
        {
            Color color = Color.Gray;
            Font font = new Font(FontName, FontSize);

            SolidBrush BrushBackColor = new SolidBrush(BackColor);
            Pen BorderPen = new Pen(color);

            Rectangle displayRectangle = new Rectangle(new Point(0, 0), new Size(Width - 1, Height - 1));

            graphics.FillRectangle(BrushBackColor, displayRectangle);
            graphics.DrawRectangle(BorderPen, displayRectangle);

            graphics.DrawString(_agha, font, Brushes.Red, 0, 0);

            context.HttpContext.Response.ContentType = "image/jpg";
            bitmap.Save(context.HttpContext.Response.OutputStream, ImageFormat.Jpeg);
        }
    }
}

and then simply define a controller action that will return this custom action result:

public class HomeController : Controller
{
    public ActionResult Index()
    {
        return View();
    }

    public ActionResult Image(string agha)
    {
        return new ImageResult(agha);
    }
}

and from within some view (~/Views/Home/Index.cshtml in my example) you could reference the action that will dynamically generate the image for you:

<img src="@Url.Action("Image", new { agha = "foo bar" })" alt="" />

Another possibility if you don't want to create an additional action to build the image is to use the Data URI scheme which basically allows you to embed the image as Base64 data directly into the HTML. One caveat with this is that not all browsers support it and ni addition to that it makes your HTML pages much larger.

回答2:

If it doesn't need to be in the ViewData (not sure if you will be able to do it in the ViewData because each resource (image, flash, the page itself) has a ContentType that doesn't change in the current request.

However, you can try this in your controller:

public ActionResult GenerateImage() {
    FileContentResult result;

    using(var memStream = new System.IO.MemoryStream()) {
        bitmap.Save(memStream, System.Drawing.Imaging.ImageFormat.Jpeg);
        result = this.File(memStream.GetBuffer(), "image/jpeg");
    }

    return result;
}

In your view, you need to call the Controller/Action:

<img src='@Url.Action("GenerateImage")' alt="" />

回答3:

Have you tried ContentResult.

You can try something like following ( not verified)

public ContentResult GetImage()
        {
            var content = new ContentResult();
            content.Content = "Image as String";
            content.ContentType = "image/jpg";
            return content;
        }

回答4:

public ContentResult GetImage()
        {
            var content = new ContentResult();
            content.Content = "Image as String";
            content.ContentType = "~image/jpg";
            return content;
        }

回答5:

public ActionResult GenerateImage() {
    FileContentResult result;

    using(var memStream = new System.IO.MemoryStream()) {
        bitmap.Save(memStream, System.Drawing.Imaging.ImageFormat.Jpeg);
        result = this.File(memStream.GetBuffer(), "image/jpeg");
    }

    return result;
}