如何解决用户代码未处理 InvalidCastException？

Question

GridViewRow row=((GridViewRow )((ImageButton )e.CommandSource ).NamingContainer );
ImageButton imgdelete = (ImageButton)row.FindControl("imgdelete");

string pid = e.CommandArgument.ToString();
if (e.CommandName == "Edit"){
    Response.Redirect("PatientRegistration.aspx?pdid=" + pid);
}
if (e.CommandName == "Delete"){
    BL_Property.PatientID = pid;
    BL_Patient.DeletePatient(BL_Property);
    ShowAllPatient();
}

我使用两个图像按钮进行编辑和删除当我点击下一页时我得到了正确的第一页我得到了一个错误

InvalidCastException was unhandled by User code
Error Message :- Unable to cast object of type 'System.Web.UI.WebControls.GridView' to type 'System.Web.UI.WebControls.ImageButton'

Answer 1

您正尝试将代码行中的 System.Web.UI.WebControls.GridView 转换为 System.Web.UI.WebControls.ImageButton，括号 ( 放错了位置，

GridViewRow row=((GridViewRow )((ImageButton )e.CommandSource ).NamingContainer );

试试这个，

GridViewRow row = (GridViewRow)  (((ImageButton)e.CommandSource).NamingContainer);

Answer 2

试试下面的代码：

GridViewRow row= (GridViewRow)(((ImageButton )e.CommandSource).NamingContainer);
mageButton imgdelete = (ImageButton)row.FindControl("imgdelete");