弄一个屏幕键盘的更好解决方案

我正在尝试制作屏幕键盘(按钮 A ，按钮 B 等). 当您按下按钮时，确实会在TextBox中添加字符.

I'm trying to make on-screen keyboard (button A, button B, etc). When you press button it does add character to TextBox.

一切正常，但如果我创建30个以上的字符，我的代码将非常庞大.

Everything is working fine but if i will create like 30 chars my code will be huge.

有什么办法可以缩短它?目前为3个按钮编写代码.

Any possible way to make it shorter? Code at the moment for 3 buttons.

// Method for each button
private void tastaturasIevade(TextBox varda_ievade, string burts)
{
    if (varda_ievade.TextLength == 0)
    {
        varda_ievade.Text = burts;
    }
    else
    {
        varda_ievade.Text = varda_ievade.Text   burts;
    }
}

// Writing buttons from on-screen keyboard
private void btn_A_Click(object sender, EventArgs e)
{
    tastaturasIevade(txt_VardaIevade, "a");
}

private void btn_B_Click(object sender, EventArgs e)
{
    tastaturasIevade(txt_VardaIevade, "b");
}

private void btn_C_Click(object sender, EventArgs e)
{
    tastaturasIevade(txt_VardaIevade, "c");
}