Select several textboxes in a panel

Question

I have several textboxes nested in a panel and I want to check if they have text or not. Although I don't want to write my code like this:

if(textbox1.Text != "" && textbox2.Text != "" ...) 
{
    ...
}

Is there any way to automate this and improve the general quality of the code itslef?

Answer 1

This can be done very easily by using OfType and All extension methods from System.Linq .

var panel = new Panel
{
    Size = new Size(500, 500),
    BackColor = Color.Red
};

panel.Controls.Add(new TextBox { Text = "Value" });
panel.Controls.Add(new TextBox { Text = "Value2" });

if (panel.Controls.OfType<TextBox>().All(x => !string.IsNullOrEmpty(x.Text)))
{
    //Do something
}

The code in the if statement will only execute if all the Text properties of TextBoxes are not empty.

Answer 2

You can use Linq extensions methods to get all Textboxes of a Panel where the property Text is not empty:

using System.Linq;

var textboxes = panel.Controls.OfType<TextBox>().Where(c => c.Text != "");

foreach ( TextBox textbox in textboxes )
{
  // ...
}

If you want to check if they are all non empty, use this:

if ( panel.Controls.OfType<TextBox>().All(c => c.Text != "") )
{
  // ...
}