In this blog you will learn how validate the textbox by using ajax:FilteredTextBoxExtender. In web application sometimes you have to restrict the user instead wrong entries. There are so many ways to validate the user entries like JavaScript, jQuery, Ajax and etc. Here you will how to validate the user entries by using ajax:FilteredTextBoxExtender.

There are the following properties of FilteredTextBoxExtender:

If set to InvalidChars, FilterType must be set to Custom;

if set to ValidChars, FilterType must contain Custom.

Lets take one example,

To allowing only "numbers":

  1. <asp:TextBox ID="txtNumbers" runat="server"></asp:TextBox>
  2. <ajax:FilteredTextBoxExtender
  3. ID="txtNumbers_FilteredTextBoxExtender"
  4. runat="server"
  5. Enabled="True"
  6. TargetControlID="txtNumbers"
  7. FilterType="Custom"
  8. FilterMode="ValidChars"
  9. ValidChars="0123456789" >
  10. </ajax:FilteredTextBoxExtender>
To allowing only "numbers and hiphen sign":
  1. <asp:TextBox ID="txtPhone" runat="server"></asp:TextBox>
  2. <ajax:FilteredTextBoxExtender
  3. ID="txtPhone_FilteredTextBoxExtender"
  4. runat="server"
  5. Enabled="True"
  6. TargetControlID="txtPhone"
  7. FilterType="Custom"
  8. FilterMode="ValidChars"
  9. ValidChars="0123456789-" >
  10. </ajax:FilteredTextBoxExtender>
To allowing only "Characters and space":
  1. <asp:TextBox ID="txtCharacters" runat="server"></asp:TextBox>
  2. <ajax:FilteredTextBoxExtender
  3. ID="txtCharacters_FilteredTextBoxExtender"
  4. runat="server"
  5. Enabled="True"
  6. TargetControlID="txtCharacters"
  7. FilterType="Custom,LowercaseLetters,UppercaseLetters"
  8. FilterMode="ValidChars"
  9. ValidChars=" " >
  10. </ajax:FilteredTextBoxExtender>
I hope you enjoyed it. please provide your valuable suggestions and feedback.