我可以遍历TextBox ID来检查/更改ASP.NET C＃中的值吗？

Question

I'm working on a project and I'm a beginner and I'm having a little trouble with this. I'm trying to check if a textbox is empty and if it is to change the value to N/A so that I can input n/a into a database instead of it not working.

Here is the code that I thought would work but didn't because the .Text property isn't near the ID anymore:

for(int i = 1; i<=17; i++)
{
if(!("tb" + i).Text)
"tb" + i.Text = "n/a";
}

I wasn't sure if the true/false would work but I never got to find out because it doesn't compile to begin with. I have 17 textboxes on my design page all with ID 'tb + i' eg tb1, tb2

thx

Answer 1

If you want to loop through the textbox ids, you have to find the control on the page first using the FindControl method.

Then you can create your loop like this:

TextBox txt;
for(int i = 1; i<=17; i++)
{
    txt = (TextBox)Page.FindControl("tb" + i);
    if(string.IsNullOrEmpty(txt.Text))
        txt.Text = "n/a";
}

Answer 2

You can use FindControl method

for(int i = 1; i<=17; i++)
{
    var textBox = Page.FindControl("tb" + i) as TextBox;

    if(textBox != null && textBox.Text == "") { ... }
}