Unable to cast object of type 'System.Web.UI.HtmlControls.HtmlInputCheckBox' to type 'System.Web.UI.WebControls.CheckBox'.

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C#

bool isSelected = false;
           foreach(GridViewRow i in DataGridTrans.Rows)
           {
               CheckBox cb = new CheckBox();

         cb = (CheckBox)i.FindControl("ChkBox1");//error showing cast as mentioned above
               if (cb != null && cb.Checked)
               {
                   isSelected = true;
                   break;
               }
           }

Posted 18-Mar-15 1:56am

Member 11526361

Updated 18-Mar-15 2:12am

RajeeshMenoth

v2

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Kornfeld Eliyahu Peter · Answer 1 · 2015-03-18T02:14:00

Solution 3

If you look at your markup you will see that the checkbox defined as

HTML

<input type="checkbox" />

and not as

ASP.NET

<asp:checkbox xmlns:asp="#unknown" />

Obviously you ca nnot convert between the two -you have to decide what to use and stick to that...

Posted 18-Mar-15 2:14am

Kornfeld Eliyahu Peter

Praneet Nadkar · Answer 2 · 2015-03-18T02:02:00

Solution 1

Try it like:

C#

var cb = (HtmlInputCheckBox)row.FindControl("ChkBox1");

The casting will depend on how have you declared it in your aspx

Posted 18-Mar-15 2:02am

Praneet Nadkar

F-ES Sitecore · Answer 3 · 2015-03-18T02:05:00

Your "ChkBox1" is probably

<input type="checkbox" runat="server"/>

which gets converted to HtmlInputCheckBox. The alternative is

<asp:Checkbox runat="server"/>

which gets converted to Checkbox. If you want to keep your markup as it is you need to use the HtmlInputCheckBox in your code-behind, not Checkbox

C#

// don't need this line
// CheckBox cb = new CheckBox();

HtmlInputCheckBox cb = (HtmlInputCheckBox)i.FindControl("ChkBox1");//error showing cast as mentioned above
 if (cb != null && cb.Checked)

To use this you need

using System.Web.UI.HtmlControls;

at the top of your page.