C# 5. Textbox限制输入

1. 限制数字位数

2. 限制只能输入数字，Textbox控件事件的“KeyPress”上双击

        private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
        {
    
    
//如果不是数字、回车，则屏蔽
            if (!(Char.IsNumber(e.KeyChar)) && e.KeyChar != (char)8)
                e.Handled = true;
        }

3. 限制只能输入范围，Textbox控件事件的“TextChanged”上双击

      private void textBox1_TextChanged(object sender, EventArgs e)
        {
    
    
            if (textBox1.Text == "")
            {
    
    
                textBox1.Text = 1.ToString();
            }
            int number = int.Parse(textBox1.Text);
            if ((number >= 1) && (number <= 8))
            {
    
    

            }
            else if(number < 1)
            {
    
    
                number = 1;
            }
            else if(number > 8)
            {
    
    
                number = 8;
            }
            textBox1.Text = number.ToString();
        }
}