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May 17, 2010

How to Add a Water mark text to an image using C#.

 Below is the method which will add a text as a water marked text to an image.


 public Bitmap WaterMarkToImage(string ImagePath, string watermark)
            {
                Bitmap bmp;
                bmp = new Bitmap(ImagePath);
                Graphics graphicsObject;
                int x, y;
                try
                {
                    //create graphics object from bitmap
                    graphicsObject = Graphics.FromImage(bmp);
                }
                catch (Exception e)
                {
                    Bitmap bmpNew = new Bitmap(bmp.Width, bmp.Height);
                    graphicsObject = Graphics.FromImage(bmpNew);


                    graphicsObject.DrawImage(bmp, new Rectangle(0, 0, 
                    bmpNew.Width, bmpNew.Height), 0, 0, bmp.Width, 
                    bmp.Height, GraphicsUnit.Pixel);
                    bmp = bmpNew;
                }


                int startsize = (bmp.Width / watermark.Length);
               //get the font size with respect to length of the string


                //x and y cordinates to draw a string
                x = 0;
                y = bmp.Height / 2;                    


               System.Drawing.StringFormat drawFormat = 
               new System.Drawing.StringFormat(StringFormatFlags.NoWrap);
                //drawing string on Image
                graphicsObject.DrawString(watermark, new Font("Verdana", 
                startsize, FontStyle.Bold), 
                new SolidBrush(Color.FromArgb(100, 255, 255, 255)), x, y, drawFormat);


                //return a water marked image
                return (bmp);
            }


Method Call:

         System.Drawing.Bitmap bmp = 
         WaterMarkToImage(@"D:\images\IMG_2933.jpg", "Intraspatial Softech");
         bmp.Save(@"D:\images\c1.jpg");


May 14, 2010

Problem calling Java-script method from codebehind with master-page and update panel

we normally use
Page.ClientScript.RegisterStartupScript(this.GetType(), "key", "Sys.Application.add_load(method_Name);", true);
to call a javascript on runtime form code behind.
Placing the above code on page load or a button click makes the script to fire on the start up of subsequent postback.


But this make not work in the case where we give a
ajax post back intead of normal postback.


so to call a javascript method on ajax postback , here we go


ScriptManager.RegisterClientScriptBlock(Page, this.GetType(), "Key", "ServiceDownAlert();", true);


Javascript Method:

function ServiceDownAlert() {
        alert("Image Not Available ! Please Try Later !");
    }