Sendkeys event is not detected inside the application in windows form application

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C#

Windows

WPF

Hi, I am new to windows app development. I am developing a Windows Form Application where the layout is as follows:

There is one textbox and i have created the keyboard inside the application using SendKeys event.

Problem is that all other application on the system are able to detect the keys but the textbox inside the application is not able to detect the keys.

What I have tried:

protected override CreateParams CreateParams
        {
            get
            {
                CreateParams param = base.CreateParams;
                param.ExStyle |= 0x08000000;
                return param;
            }
        }

private void button14_Click(object sender, EventArgs e)
        {//one of the Key in Keyboard
            if (checkBox1.Checked)
            {
                SendKeys.Send("Q");
            }
            else
            {
                SendKeys.Send("q");
            }
        }

private void textBox1_TextChanged(object sender, EventArgs e)
        {

        }