winform获得键盘输入的按键

获得键盘输入的按键
1 首先设置 窗体属性KeyPreview = true;
（ 这是窗体属性 而不是控件的属性 记清楚了）
举例子 MedicineUse是主窗体 cmbDoctor是combox2控件获得焦点

2 private void MedicineUse_KeyDown(object sender, KeyEventArgs e)
        {
            Keys k = e.KeyCode;
            if (k == Keys.F12)
            {
                this.cmbDoctor.Focus();
            }
        }
        combox2获得焦点后  Enter键等于TAB键
         private void comboBox2_KeyPress_1(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == (char)Keys.Enter)
            {
                SendKeys.Send("{tab}"); 
            }
        }


        SendKeys.Send("{tab}");表示向程序发送tab键




        private void FrmHospital_KeyDown(object sender, KeyEventArgs e)
        {
            switch (e.KeyCode)
            {
                case Keys.F2: btnadd_Click(sender, e); break;
                case Keys.F3: btnmodify_Click(sender, e); break;
                case Keys.F4: btndelete_Click(sender, e); break;
            }
        }