Charith's Blog: 2011

Saturday, December 17, 2011

How to validate a number between 0-24 with Java Scripts

<%@ Page Language="C#" %>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <script language="javascript" type="text/javascript">
        function checkIt(obj, evt) {
            evt = (evt) ? evt : window.event
            var charCode = (evt.which) ? evt.which : evt.keyCode
            if ((charCode < 45 || charCode > 57) && charCode != 8 && charCode != 37 && charCode != 39) {
                alert("This field accepts numbers only")
                return false
            }
            var t = (charCode / 1) - 48;
            var v = obj.value + t;
            var value = v / 1;
            if(value > 24){ 
                alert("Number should be less than 24");
                return false;
            }
            return true
        }
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox runat="server" ID="txtNumber" onKeyPress='javascript:return checkIt(this, event)' />
    </div>
    </form>
</body>
</html>

Wednesday, December 14, 2011

How to retain the password in a postback

<%@ Page Language="C#" %>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title>Test Page</title>
    <script runat="server">
        public string Password
        {
            get { return ViewState["Password"] as string; }
            set { this.ViewState["Password"] = value; }
        }
        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);
            if (this.IsPostBack)
            {
                if (!string.IsNullOrEmpty(this.txtPassword.Text))
                    this.Password = this.txtPassword.Text;
                this.txtPassword.Attributes.Add("value", this.Password ?? string.Empty);
            }
        }
    </script>
</head>
<body>
    <form  id="aspNetForm" runat="server">
        UserName: <asp:TextBox runat="server" ID="txtName" />
        Password: <asp:TextBox runat="server" ID="txtPassword" TextMode="Password" />
        <hr />
        <asp:Button runat="server" ID="btnSave" Text="Save" />
    </form>
</body>
</html>

Tuesday, December 13, 2011

Html Header Tag Sizes

H1 - 24pt / 32px
H2 - 18pt / 24px
H3 - 14pt / 18px
H4 - 12pt / 15px
H5 - 10pt / 13px
H6 - 8pt / 11px

Above are the default font sizes in points and their approximate sizes in pixels

Friday, August 19, 2011

How to upload a external image link url and save on the disk

We can get the use of HttpWebRequest and HttpWebResponse to send the request and get the response. Then response.GetResponseStream() will give us a stream of the image where we can use that stream to create a Image object like Image image = Image.FromStream(stream)

Markup:

<%@ Page Language="C#" CodeBehind="Test.aspx.cs" Inherits="ActiveTest.Test" %>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox runat="server" ID="txtUpload" 
            Text="http://www.web-sphere.co.uk/web/websphere/blog/bloggerheader.jpg" />
        <asp:Button runat="server" ID="btnUpload" OnClick="Upload" Text="Upload" />
    </div> 
    </form>
</body>
</html>

Code:

namespace ActiveTest
{
    public partial class Test : Page
    {
        protected void Upload(object sender, EventArgs e)
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(this.txtUpload.Text);
            HttpWebResponse response = request.GetResponse() as HttpWebResponse;
            Stream stream = response.GetResponseStream();         
            ///
            /// use response content type to findout the image type, 
            /// here I just use jpg to simplify the story.
            /// 
            System.Drawing.Image image = System.Drawing.Image.FromStream(stream);
            image.Save(this.Server.MapPath(string.Format("~/Uploads/{0}.jpg",Guid.NewGuid())));
        }
    }
}