C# 数字键盘控件

【实例截图】

【核心代码】

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace KeyboardControl
{
    public partial class ControlKeyboard : UserControl
    {
        public ControlKeyboard()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SetNumber("1");
        }

        private void button2_Click(object sender, EventArgs e)
        {
            SetNumber("2");
        }

        private void button3_Click(object sender, EventArgs e)
        {
            SetNumber("3");
        }

        private void button4_Click(object sender, EventArgs e)
        {
            SetNumber("4");
        }

        private void button5_Click(object sender, EventArgs e)
        {
            SetNumber("5");
        }

        private void button6_Click(object sender, EventArgs e)
        {
            SetNumber("6");
        }

        private void button7_Click(object sender, EventArgs e)
        {
            SetNumber("7");
        }

        private void button8_Click(object sender, EventArgs e)
        {
            SetNumber("8");
        }

        private void button9_Click(object sender, EventArgs e)
        {
            SetNumber("9");
        }

        private void button10_Click(object sender, EventArgs e)
        {
            string text = textBox1.Text;
            if (text == "" || text == "请输入")
            {
            }
            else
            {
                text = text.Substring(0, text.Length - 1);
                if (text == "")
                {
                    textBox1.Text = "请输入";
                }
                else
                {
                    textBox1.Text = text;
                }
            }
        }

        private void button11_Click(object sender, EventArgs e)
        {
            SetNumber("0");
        }

        private void button12_Click(object sender, EventArgs e)
        {
            MessageBox.Show("输入的数字为"   textBox1.Text);
        }

        private void SetNumber(string number)
        {
            string text = textBox1.Text;
            if (text == "请输入")
            {
                textBox1.Text = number;
            }
            else
            {
                textBox1.Text = text  = number;
            }
        }
    }
}