String Comparison

Posted by Sibin.rhythm under ASP.NET on 8/26/2009 | Views : 2345 | Status : [Member] | Replies : 4

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Hi
I completed my project work . , but only one problem is Sql injection. For this project I used asp.net platform with c#.

I need to compare each letters in the textbox value., if thre has any letters like <,>,.,!,<!,create ,etc..then the the error message should display.
For that i wrote


 if(String.Compare(text_compname.text,"<"))
 {
  lablel1.visible=true;            //    lbale1=" Invalid Charrecter"
 }
  else
 {
// regular statements
}

When Run the program with this code there is an error like "cannot implicitly convert type'int' to 'bool'

can u find any mistake in this code?????
weather the string comparison syntax is wrong???

weather there has any other coding for string comparison in asp.net with c#??

please help me............

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Posted by: Vuyiswamb on: 8/27/2009 [Member] [MVP] [Administrator] NotApplicable

0	Good Morning Sibin.rhythm write this Statement like this If(text_compname.text == "<") { lablel1.visible=true; // lbale1=" Invalid Charrecter" } else { // regular statements } if you want more info on SQL Injection look at this Article http://www.dotnetfunda.com/articles/article295.aspx One more thing Sibin.rhythm When you post a code in the Forum, there is a link that says code. This will Format everything in good way. Thank you for posting at Dotnetfunda Vuyiswa Maseko Thank you for posting at Dotnetfunda [Administrator] Sibin.rhythm, if this helps please login to Mark As Answer. \| Alert Moderator

Good Morning Sibin.rhythm

write this Statement like this


If(text_compname.text  == "<")

{

lablel1.visible=true;            //    lbale1=" Invalid Charrecter"

}

else

{

// regular statements

 }

if you want more info on SQL Injection look at this Article

http://www.dotnetfunda.com/articles/article295.aspx

One more thing Sibin.rhythm

When you post a code in the Forum, there is a link that says code. This will Format everything in good way.

Thank you for posting at Dotnetfunda

Vuyiswa Maseko

Thank you for posting at Dotnetfunda
[Administrator]

Sibin.rhythm, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Sibin.rhythm on: 8/27/2009 [Member] Starter

0	Thankyou Mr.Vuyiswamb But I need to check the value in the textbox charrecter by charrecter. If "<" symbol any where in the word should detect..if it is the first letter or last letter,or in the middles.So I need to check the Textbox value by each charrecter.. Plese help me........... Sibin.rhythm, if this helps please login to Mark As Answer. \| Alert Moderator

Posted by: Vuyiswamb on: 8/27/2009 [Member] [MVP] [Administrator] NotApplicable

0	Good Day That can be easily done this was String Test = "VuytiswaMaseko<"; if (Test.Contains("<")) { Response.Write("<script>alert('It has the Character');</script>"); } else { Response.Write("<script>alert('Oops naa its not there');</script>"); } now that means your code will look like this String text_compname = text_compname.text; if(text_compname.Contains("<")) { lablel1.visible=true; // lbale1=" Invalid Charrecter" } else { // regular statements } Thank you for posting at Dotnetfunda Vuyiswa Maseko Thank you for posting at Dotnetfunda [Administrator] Sibin.rhythm, if this helps please login to Mark As Answer. \| Alert Moderator

Good Day

That can be easily done this was


     String Test = "VuytiswaMaseko<";



        if (Test.Contains("<"))

        {

            Response.Write("<script>alert('It has the Character');</script>");

        }

        else

        {

            Response.Write("<script>alert('Oops naa its not there');</script>");

        }

now that means your code will look like this

String text_compname = text_compname.text;



if(text_compname.Contains("<"))

 {

  lablel1.visible=true;            //    lbale1=" Invalid Charrecter"

 }

  else

 {

// regular statements

}

Thank you for posting at Dotnetfunda

Vuyiswa Maseko

Thank you for posting at Dotnetfunda
[Administrator]

Sibin.rhythm, if this helps please login to Mark As Answer. | Alert Moderator

Posted by: Lakhangarg on: 8/27/2009 [Member] [Moderator] Silver

0	Hi Sibin- Check this JavaScript Function to Check special charcters: function chkSpecialChars(input) { var iChars = "!@#$%^&()+=-[]\\\';,./{}\|\":<>?"; for (var i = 0; i < input.length; i++) { if (iChars.indexOf(input.charAt(i)) != -1) { alert ( "You are using special characters. \nThese are not allowed.\n Please remove them and try again."); return false; } } return true; } Replace This line var iChars = "!@#$%^&()+=-[]\\\';,./{}\|\":<>?"; with your character that you want to validate. input is document.getElementId('yourtextboxid'); Thanks & Regards Lakhan Pal Garg http://lakhangarg.blogspot.com Sibin.rhythm, if this helps please login to Mark As Answer. \| Alert Moderator

Hi Sibin-

Check this JavaScript Function to Check special charcters:

function chkSpecialChars(input)

{

var iChars = "!@#$%^&*()+=-[]\\\';,./{}|\":<>?"; 

for (var i = 0; i < input.length; i++)

{

if (iChars.indexOf(input.charAt(i)) != -1)

{

alert (

"You are using special characters. \nThese are not allowed.\n Please remove them and try again."); return false;

}

}

return true;

}

Replace This line var iChars = "!@#$%^&*()+=-[]\\\';,./{}|\":<>?"; with your character that you want to validate.

input is document.getElementId('yourtextboxid');

Thanks & Regards
Lakhan Pal Garg
http://lakhangarg.blogspot.com

Sibin.rhythm, if this helps please login to Mark As Answer. | Alert Moderator

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