[C#][Control]BitsControl - Concept and Simple Implementation

有些人可能還看不出前一篇指撥開關的用途，其實做些變化指撥開關還可以用來做些簡易的硬體設定。像是做個控制項可以載入一個Byte的資料，並允許使用者直接去調整設定，可用在GPIB、I2C之類的通訊界面設定，設定一些位置資訊。

實作時可建立一個新的使用者控制項，在裡面加入FlowLayoutPanel控制項，再加入八個SwitchButton，與一個Panel去分隔。這邊可將控制項的BorderStyle設為FixedSingle，整個控制項比較會有一體的感覺。

接著必須在整個控制項SizeChanged時調整裡面的SwitchButton大小，這樣做出來的控制項才能適應不同的大小。

private void BitsControl_SizeChanged(object sender, EventArgs e)
{
  int width = flowLayoutPanel1.ClientSize.Width - panel1.Width - bit8.Margin.Left * 16 - panel1.Margin.Left * 2;
  if(width < 0)
      return;

    int bitWith = width / 8;

    bit8.Width = bitWith;
    bit7.Width = bitWith;
    bit6.Width = bitWith;
    bit5.Width = bitWith;
    bit4.Width = bitWith;
    bit3.Width = bitWith;
    bit2.Width = bitWith;
    bit1.Width = bitWith;

    int bitHeight = flowLayoutPanel1.ClientSize.Height - bit8.Margin.Top * 2;
    bit8.Height = bitHeight;
    bit7.Height = bitHeight;
    bit6.Height = bitHeight;
    bit5.Height = bitHeight;
    bit4.Height = bitHeight;
    bit3.Height = bitHeight;
    bit2.Height = bitHeight;
    bit1.Height = bitHeight;
}

接著必須為控制項加入最主要的功能，也就是必須要能讓它載入權重值或是HexString，依不同的設定值調整SwitchButton。這部分的實作也很簡單，只要從高權位的開始處理，若是目前剩餘的權重值高過當前SwitchButton的權重值，代表當前的SwitchButton應該調為On的狀態，並將目前剩餘的權重值扣掉當前SwitchButton的權重值，不然則調為Off的狀態。

public void LoadBitsState(int weightValue)
{
    SwitchButton[] switchButtons = { bit1, bit2, bit3, bit4, bit5, bit6, bit7, bit8 };
    for (int i = 8; i >= 1; --i)
    {
        int currentWeightValue = int.Parse(Math.Pow(2 , i - 1).ToString());
        SwitchButton currentSwitchButton = switchButtons[i - 1];
        if (weightValue >= currentWeightValue)
        {
            currentSwitchButton.State = SwitchButton.SwitchState.On;
            weightValue -= currentWeightValue;
        }
        else
        {
            currentSwitchButton.State = SwitchButton.SwitchState.Off;
        }
    }
}

public void LoadBitsState(string hexValue)
{
    LoadBitsState(Convert.ToInt32(hexValue, 16));
}

簡易的實作到這邊已經完成了，實際運行時會整個控制項會像下面這樣。

[C#][Control]BitsControl - Concept and Simple Implementation

這邊只是個簡易的範例，當然在實際運用時可能必須視需要將權重值或是HexString開出，並能讓使用者透過介面選取適時的影響取回的權重值或是HexString。

最後這邊附上較為完整的程式碼：

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

namespace WindowsFormsApplication6
{
    public partial class BitsControl : UserControl
    {
        public BitsControl()
        {
            InitializeComponent();
        }

        public void LoadBitsState(int weightValue)
        {
            SwitchButton[] switchButtons = { bit1, bit2, bit3, bit4, bit5, bit6, bit7, bit8 };
            for (int i = 8; i >= 1; --i)
            {
                int currentWeightValue = int.Parse(Math.Pow(2 , i - 1).ToString());
                SwitchButton currentSwitchButton = switchButtons[i - 1];
                if (weightValue >= currentWeightValue)
                {
                    currentSwitchButton.State = SwitchButton.SwitchState.On;
                    weightValue -= currentWeightValue;
                }
                else
                {
                    currentSwitchButton.State = SwitchButton.SwitchState.Off;
                }
            }
        }

        public void LoadBitsState(string hexValue)
        {
            LoadBitsState(Convert.ToInt32(hexValue, 16));
        }

        private void BitsControl_SizeChanged(object sender, EventArgs e)
        {
          int width = flowLayoutPanel1.ClientSize.Width - panel1.Width - bit8.Margin.Left * 16 - panel1.Margin.Left * 2;
          if(width < 0)
              return;

            int bitWith = width / 8;

            bit8.Width = bitWith;
            bit7.Width = bitWith;
            bit6.Width = bitWith;
            bit5.Width = bitWith;
            bit4.Width = bitWith;
            bit3.Width = bitWith;
            bit2.Width = bitWith;
            bit1.Width = bitWith;

            int bitHeight = flowLayoutPanel1.ClientSize.Height - bit8.Margin.Top * 2;
            bit8.Height = bitHeight;
            bit7.Height = bitHeight;
            bit6.Height = bitHeight;
            bit5.Height = bitHeight;
            bit4.Height = bitHeight;
            bit3.Height = bitHeight;
            bit2.Height = bitHeight;
            bit1.Height = bitHeight;
        }
    }
}