Replace Escape Character (C#)

Introduction:

For the beginning we are facing the same problem while inserting a text with escaped character like single quote (') into the database. That's why we've solved this problem by creating our own library and reuse that library.

This example is based on ASP.Net 2.0 with Visual Studio 2005 and using C#.

Start the project:

1. Start Visual Studio and start a new "Web Site". Give the project name "ReplaceEscapeCharacters".
   
   
   
2. Give a title of the "default.aspx" file "Replace Escape Characters" and rename the "Form" ID to "frmReplaceEscapeCharacters". This is a optional work.
   
   
   
3. Click right mouse button in the project name of "Solution Explorer". A pop-up menu will appear, choose "Add New Item…" and click.
   
   
   
4. A Template library of Visual Studio will appear. Choose a "Class" Template and give a name "MyClass.cs" of the template.
   
   
   
5. A message box will appear showing whether you want to add that class file into "App_Code" folder or not. Choose "Yes" from the three options. It will make a "App_Code" folder into your project and add the newly build "MyClass.cs" file into that folder. If you add your class into "App_Code" folder, that class file will be easily accessible all over your project(s).
   
   
   
   
   
6. Now right the following codes into "MyClass.cs".

   public static string ReplaceEscapeChars(string str)
   {
       //If the string is null
       if (str == null)
           return str;
   
       //If the string is empty
       if (str == "")
           return str;
   
       //Replaces single quote (') with two (2) single quotes ('')
       //solves the problem of inserting, updating or selecting a text with single quote (')
       //i.e.: Cox's Bazar, World's economy etc.
       str = str.Replace("'", "''");
       return str;
   }
   

   
   

Using the library:

1. Add some control into the "default.aspx" file

   Name: <asp:TextBox ID="txtName" runat="server" />
   Address: <asp:TextBox ID="txtAddress" runat="server" />
   Age: 
   <asp:DropDownList ID="cboSex" runat="server">
       <asp:ListItem Value="M"> Male </ asp:ListItem>
       <asp:ListItem Value="F"> Female </ asp:ListItem>
   </asp:DropDownList>
   <asp:Button ID="btnSubmit" runat="server" Text="Submit" OnClick="btnSubmit_Click" />
   
   <asp:Label ID="lblShowResult" runat="server" Text="" />
   

   
   
2. In the click event of the submit button write the following code

   protected void btnSubmit_Click(object sender, EventArgs e)
   {
       //Declare variables
       string strName = "", strAddress = "", strSex = "";
       string strMyResult = "";
   
       //Collecting values from the front-end
       strName     = MyClass.ReplaceEscapeChars(txtName.Text);
       strAddress  = MyClass.ReplaceEscapeChars(txtAddress.Text);
       strSex      = cboSex.SelectedItem.ToString();
   
       //Building the string for showing the result
       strMyResult  = "<b>Name:</b> " + strName + "<br />";
       strMyResult += "<b>Address:</b> " + strAddress + "<br />";
       strMyResult += "<b>Sex:</b> " + strSex + "<br />";
   
       //Showing the result into the text
       lblShowResult.Text = strMyResult;
   }
   

   
   
3. Run the project
   
   
   
4. You've seen that Cox's Bazar has been changed to Cox''s Bazar. Now if you want this value into the database, it will not generate any error.