converting types...

im trying to download an image and show in a picturebox control...

i've already got so far:

PHP Code:

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            WebClient wcClient = new WebClient();
            byte[] mBuffer = wcClient.DownloadData("http://www.vbforums.com/images/ads/current.gif"); 


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but now i realised that in vb.net we have a function called CType() that isnt avaliable in C#..how do i convert that byte[]array into a bitmap image so i can show it in my picturebox without having to write it to the disk? lol

You use casting, I believe there is more than one way to do it but one way is to put the target type in parenthesis in front of the object you want to convert.

VB Code:

WebClient wcClient = new WebClient();
            byte[] mBuffer = [b](byte[])[/b] wcClient.DownloadData("http://www.vbforums.com/images/ads/current.gif");

what exactly did that do?

i think the best way is to maybe convert to a stream and then use the GetStream or something like that that the Image Type supports lol or what?

Quote:

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what exactly did that do?

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He is casting the return value that is returned from the downloadData method. Casting means converting one data type to another compatable data type. For instance:

Code:

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    float myFloat = 145.654f
    int myInt = (int) myFloat;

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Without explicity casting myFloat to myInt, the compiler would puke all over this. Reason being, we are trying to stuff a larger data type into a smaller type, which is known as a narrowing conversion (potential loss of data). When you explicity cast a data type this way, you are treating the data type as another data type.

Here ya go, you can add in your own exception handling if you would like:

Code:

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using System;
using System.IO;
using System.Net;
using System.Text;

namespace ImageStream
{
        public class ImageToDownload
        {
                string urlToDownload;
                const string prefix = "http://";

                public ImageToDownload(string uRL)
                {
                        this.urlToDownload = uRL;
                }

                public MemoryStream BeginDownload()
                {
                        MemoryStream msImage;
                        WebClient wcClient = new WebClient();

                        if  (!urlToDownload.ToLower().StartsWith("http://"))
                        {
                                urlToDownload = prefix + urlToDownload;
                        }

                        msImage = new MemoryStream(wcClient.DownloadData (urlToDownload));
                        return msImage;                                       
                }
        }
}

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Code:

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private void button1_Click(object sender, System.EventArgs e)
{                       
        string pathToImage = "http://www.vbforums.com/images/ads/current.gif";
        ImageToDownload myImage = new ImageToDownload(pathToImage);                       
        MemoryStream stream = myImage.BeginDownload();
        pictureBox1.Image = Image.FromStream(stream);
}

---

hmm let me try lol

ah tks worked like a sharm...mmm..but what is a memorystream? lol

btw where are tuturials about casting..? that seems interesting lol

The MemoryStream class creates streams that have memory as a backing store instead of a disk or a network connection. MemoryStream encapsulates data stored as an unsigned byte array that is initialized upon creation of a MemoryStream object, or the array can be created as empty.

Do a search on casting, and I'm sure you'll find many examples.