Validation control on serverside using dropdown and textbox .asp c# code
Server side validation in a dropdown list
file name: TravelDetailsInsert.aspx
In this section we are going to compare the two location should not be same. If the location will be same then it will five an error that Both locations are same"
In the below section AutoPostBack="true" is very much important
Also OnSelectedIndexChanged="ToLocation_SelectedIndexChanged1" this code is important to create the function
inside the .aspx.cs file
<span class="pln"> </span><span class="tag"><table></span><span class="pln"> </span><span class="tag"><tr></span><span class="pln"> </span><span class="tag"><td></span><span class="pln"> </span><span class="tag"><asp:Label</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"Label2"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">Text</span><span class="pun">=</span><span class="atv">"From Location"</span><span class="tag">></asp:Label></span><span class="pln"> </span><span class="tag"></td></span><span class="pln"> </span><span class="tag"><td></span><span class="pln"> </span><span class="tag"><asp:DropDownList</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"FromLocation"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">AutoPostBack</span><span class="pun">=</span><span class="atv">"true"</span><span class="tag">></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Please Select</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Thiruvananthapuram</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Kochi</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Kozhikode</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Kollam</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Thrissur</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Kannur</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Alappuzha</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"></asp:DropDownList></span><span class="pln"> </span><span class="tag"><asp:RequiredFieldValidator</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"RequiredFieldValidator1"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">ErrorMessage</span><span class="pun">=</span><span class="atv">"Select the Base location"</span><span class="pln"> </span><span class="atn">ControlToValidate</span><span class="pun">=</span><span class="atv">"FromLocation"</span><span class="tag">></asp:RequiredFieldValidator></td></span><span class="pln"> </span><span class="tag"></tr></span><span class="pln"> </span><span class="tag"><tr></span><span class="pln"> </span><span class="tag"><td></span><span class="pln"> </span><span class="tag"><asp:Label</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"Label3"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">Text</span><span class="pun">=</span><span class="atv">"To Location"</span><span class="tag">></asp:Label></span><span class="pln"> </span><span class="tag"></td></span><span class="pln"> </span><span class="tag"><td></span><span class="pln"> </span><span class="tag"><asp:DropDownList</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"ToLocation"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">AutoPostBack</span><span class="pun">=</span><span class="atv">"true"</span><span class="pln"> </span><span class="atn">OnSelectedIndexChanged</span><span class="pun">=</span><span class="atv">"</span><span class="typ">ToLocation_SelectedIndexChanged1</span><span class="atv">"</span><span class="tag">></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Thiruvananthapuram</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Kochi</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Kozhikode</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Kollam</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Thrissur</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Kannur</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"><asp:ListItem></span><span class="pln">Alappuzha</span><span class="tag"></asp:ListItem></span><span class="pln"> </span><span class="tag"></asp:DropDownList></span><span class="pln"> </span><span class="tag"><asp:RequiredFieldValidator</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"RequiredFieldValidator2"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">ErrorMessage</span><span class="pun">=</span><span class="atv">"Select Your Destination Location"</span><span class="pln"> </span><span class="atn">ControlToValidate</span><span class="pun">=</span><span class="atv">"ToLocation"</span><span class="tag">></asp:RequiredFieldValidator></span><span class="pln"> </span><span class="tag"><asp:CustomValidator</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"CustomValidator1"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">ErrorMessage</span><span class="pun">=</span><span class="atv">"TO and FROM is same"</span><span class="pln"> </span><span class="atn">ControlToValidate</span><span class="pun">=</span><span class="atv">"ToLocation"</span><span class="tag">></asp:CustomValidator></span><span class="pln"> </span><span class="tag"><asp:Label</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"Label6"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">Text</span><span class="pun">=</span><span class="atv">"Label"</span><span class="pln"> </span><span class="atn">ForeColor</span><span class="pun">=</span><span class="atv">"#FF3399"</span><span class="tag">></asp:Label></span><span class="pln"> </span><span class="tag"></td></span><span class="pln"> </span><span class="tag"></tr></span><span class="pln"> </span><span class="tag"></table></span><span class="pln"> </span>
file name: TravelDetailsInsert.aspx.cs
This event will occur when anyone select the second dropdown list. this event is called SelectedIndexChanged
<span class="pln"> </span><span class="kwd">protected</span><span class="pln"> </span><span class="kwd">void</span><span class="pln"> </span><span class="typ">ToLocation_SelectedIndexChanged1</span><span class="pun">(</span><span class="kwd">object</span><span class="pln"> sender</span><span class="pun">,</span><span class="pln"> </span><span class="typ">EventArgs</span><span class="pln"> e</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="typ">ToLocation</span><span class="pun">.</span><span class="typ">Text</span><span class="pln"> </span><span class="pun">==</span><span class="pln"> </span><span class="typ">FromLocation</span><span class="pun">.</span><span class="typ">Text</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><span class="typ">Label6</span><span class="pun">.</span><span class="typ">Text</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> </span><span class="str">"Location Should not same"</span><span class="pun">;</span><span class="pln"> </span><span class="pun">}</span><span class="pln"> </span><span class="kwd">else</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><span class="typ">Label6</span><span class="pun">.</span><span class="typ">Text</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> </span><span class="str">""</span><span class="pun">;</span><span class="pln"> </span><span class="pun">}</span><span class="pln"> </span><span class="pun">}</span><span class="pln"> </span>
Server side validation in a Text box
In this part we are going to learn a serverside validation using a awesome feature of the .net which is called as TextChanged
In this part we will take a value from the one textbox which is DistanceinKm and we will calculate the
EstimatedAmount and we will put that value indide another text box
Note: the important part of the below code is onTextChanged="DistanceinKm_TextChanged" AutoPostBack="true"
<span class="pln"> </span><span class="tag"><table></span><span class="pln"> </span><span class="tag"><tr></span><span class="pln"> </span><span class="tag"><td></span><span class="pln"> </span><span class="tag"><asp:Label</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"Label5"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">Text</span><span class="pun">=</span><span class="atv">"Distance in Km "</span><span class="tag">></asp:Label></span><span class="pln"> </span><span class="tag"></td></span><span class="pln"> </span><span class="tag"><td></span><span class="pln"> </span><span class="tag"><asp:TextBox</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"DistanceinKm"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">onTextChanged</span><span class="pun">=</span><span class="atv">"</span><span class="typ">DistanceinKm_TextChanged</span><span class="atv">"</span><span class="pln"> </span><span class="atn">AutoPostBack</span><span class="pun">=</span><span class="atv">"true"</span><span class="pln"> </span><span class="tag">></asp:TextBox></span><span class="pln"> </span><span class="pun"><%--</span><span class="pln"> </span><span class="pun"><</span><span class="pln">asp</span><span class="pun">:</span><span class="typ">Button</span><span class="pln"> ID</span><span class="pun">=</span><span class="str">"Button2"</span><span class="pln"> runat</span><span class="pun">=</span><span class="str">"server"</span><span class="pln"> </span><span class="typ">Text</span><span class="pun">=</span><span class="str">"See Car Rent"</span><span class="pln"> </span><span class="typ">OnClick</span><span class="pun">=</span><span class="str">"TextBox2_TextChanged"</span><span class="pln"> </span><span class="pun">/>--</span><span class="pln">%> </span><span class="tag"><asp:RequiredFieldValidator</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"RequiredFieldValidator4"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">ErrorMessage</span><span class="pun">=</span><span class="atv">"Select the distance"</span><span class="pln"> </span><span class="atn">ControlToValidate</span><span class="pun">=</span><span class="atv">"DistanceinKm"</span><span class="tag">></asp:RequiredFieldValidator></span><span class="pln"> </span><span class="tag"></td></span><span class="pln"> </span><span class="tag"></tr></span><span class="pln"> </span><span class="tag"><tr></span><span class="pln"> </span><span class="tag"><td></span><span class="pln"> </span><span class="tag"><asp:Label</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"EstimatedAmountText"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="pln"> </span><span class="atn">Text</span><span class="pun">=</span><span class="atv">"EstimatedAmount"</span><span class="tag">></asp:Label></span><span class="pln"> </span><span class="tag"></td></span><span class="pln"> </span><span class="tag"><td></span><span class="pln"> </span><span class="tag"><asp:TextBox</span><span class="pln"> </span><span class="atn">ID</span><span class="pun">=</span><span class="atv">"EstimatedAmount"</span><span class="pln"> </span><span class="atn">runat</span><span class="pun">=</span><span class="atv">"server"</span><span class="tag">></asp:TextBox></span><span class="pln"> </span><span class="tag"></td></span><span class="pln"> </span><span class="tag"></tr></span><span class="pln"> </span><span class="tag"></table></span><span class="pln"> </span><span class="tag"><h3></span><span class="pln"> </span>
file name: TravelDetailsInsert.aspx.cs
<span class="pln"> </span><span class="kwd">protected</span><span class="pln"> </span><span class="kwd">void</span><span class="pln"> </span><span class="typ">DistanceinKm_TextChanged</span><span class="pun">(</span><span class="kwd">object</span><span class="pln"> sender</span><span class="pun">,</span><span class="pln"> </span><span class="typ">EventArgs</span><span class="pln"> e</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln"> </span><span class="kwd">int</span><span class="pln"> distance </span><span class="pun">=</span><span class="pln"> </span><span class="typ">Convert</span><span class="pun">.</span><span class="typ">ToInt32</span><span class="pun">(</span><span class="typ">DistanceinKm</span><span class="pun">.</span><span class="typ">Text</span><span class="pun">);</span><span class="pln"> </span><span class="kwd">int</span><span class="pln"> rate </span><span class="pun">=</span><span class="pln"> </span><span class="lit">10</span><span class="pln"> </span><span class="pun">*</span><span class="pln"> distance</span><span class="pun">;</span><span class="pln"> </span><span class="typ">EstimatedAmount</span><span class="pun">.</span><span class="typ">Text</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> </span><span class="typ">Convert</span><span class="pun">.</span><span class="typ">ToString</span><span class="pun">(</span><span class="pln">rate</span><span class="pun">);</span><span class="pln"> </span><span class="pun">}</span><span class="pln"> </span>
