比较完整的异常处理和提示框架

例程：

bool flag = false;

SqlConnection con =
new SqlConnection(Constr);

con.Open();

SqlCommand cmd = new
SqlCommand(cmdtxt,con);

try

{

//执行SQL语句

cmd.ExecuteNonQuery();

flag = true;

}

catch

{

flag = false;

}

finally

{

//释放资源

cmd.Dispose();

con.Close();

}

if (flag)

{

Response.Write("<script language=javascript>alert('添加成功!');location='Default.aspx'</script>");

}

else

{

Response.Write("<script language=javascript>alert('添加失败！');location='javascript:history.go(-1)'</script>");

}