如何使用标签来更改具有该标签的多个项目的属性？

Question

I have multiple 6 buttons, that when you click on each button, they will change their properties, and deactivate other properties in the others of the same tag.

The code I have at the moment doesn't use tags and is very long winded for doing this to every button click:

private void buttonBritishGas_Click(object sender, EventArgs e)
    {
        buttonBritishGas.FlatStyle = FlatStyle.Flat;
        buttonBritishGas.FlatAppearance.BorderSize = 3;
        buttonBritishGas.FlatAppearance.BorderColor = Color.Blue;

        buttonEDF.FlatStyle = FlatStyle.Standard;
        buttonEDF.FlatAppearance.BorderSize = 1;
        buttonEDF.FlatAppearance.BorderColor = Color.White;

        buttonEON.FlatStyle = FlatStyle.Standard;
        buttonEON.FlatAppearance.BorderSize = 1;
        buttonEON.FlatAppearance.BorderColor = Color.White;

        buttonNPower.FlatStyle = FlatStyle.Standard;
        buttonNPower.FlatAppearance.BorderSize = 1;
        buttonNPower.FlatAppearance.BorderColor = Color.White;

        buttonScottishPower.FlatStyle = FlatStyle.Standard;
        buttonScottishPower.FlatAppearance.BorderSize = 1;
        buttonScottishPower.FlatAppearance.BorderColor = Color.White;

        buttonSSE.FlatStyle = FlatStyle.Standard;
        buttonSSE.FlatAppearance.BorderSize = 1;
        buttonSSE.FlatAppearance.BorderColor = Color.White;

The tag I am using is "Supplier" and here is the code I have attempted at the moment:

private void buttonBritishGas_Click(object sender, EventArgs e)
    {

        buttonBritishGas.Tag = "SelectedSupplier";

        foreach (Control c in Controls)
        {
            if (c.Tag.Equals("SelectedSupplier"))
            {
                FlatStyle = FlatStyle.Flat;
                FlatAppearance etc...;
            }
        }

        foreach (Control c in Controls)
        {
            if (c.Tag.Equals("Supplier"))
            {
                FlatStyle = FlatStyle.Standard;
                FlatAppearance etc...;
            }
        }

Any help is appreciated!

EDITED:

private void ChangeStyleByTag(Control parent, string tag, object sender, EventArgs e)
    {

        foreach (Control c in parent.Controls)
        {
            if (c.Tag != null && c.Tag.Equals(tag))
            {
                Button b = (Button)sender;
                b.FlatStyle = FlatStyle.Flat;
                b.FlatAppearance.BorderSize = 3;
                b.FlatAppearance.BorderColor = Color.Blue;
            }
            else
            ChangeStyleByTag(c, tag);
        }
    }

    private void buttonBritishGas_Click(object sender, EventArgs e)
    {
        buttonBritishGas.Tag = "SelectedSupplier";
        ChangeStyleByTag(this."SelectedSupplier");
        ChangeStyleByTag(this."Supplier");
    }

Answer 1

You have to loop recursively inside the form's control tree:

    private void ChangeStyleByTag(Control parent, string tag)
    {
        foreach (Control c in parent.Controls)
        {
            if (c.Tag!=null && c.Tag.Equals(tag))
            {
                (c as Button).FlatStyle = FlatStyle.Flat;
                (c as Button).FlatAppearance.BorderSize = 3;
                (c as Button).FlatAppearance.BorderColor = Color.Blue;
            }
            else
                ChangeStyleByTag(c, tag);
        }
    }

    private void buttonBritishGas_Click(object sender, EventArgs e)
    {

        ChangeStyleByTag(this, "SelectedSupplier");
        ChangeStyleByTag(this, "Supplier");
    }