[C#]取得字串中的數字

using System.Text.RegularExpressions;

整數

string str = "測試123abc測試";

string Result =Regex.Replace(str, @"[^0-9]+", "");

小數

string str = "測試123.123測試"; 
string Result =Regex.Replace(str, @"[^\d.\d]", "");

[C#]Split使用字串分割

string str1= "aabbcc"; 

string[] str= str1.Split(new string[] { "bb" }, StringSplitOptions.RemoveEmptyEntries);

[C#]DataGridView新增全選功能

/// <summary>
/// Form Load
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void Form_Load(object sender, EventArgs e)
{
         ckBox.Text = "";
         ckBox.Checked = false;
         System.Drawing.Rectangle rect = dgvList.GetCellDisplayRectangle(0, -1, true);
         ckBox.Size = new System.Drawing.Size(13, 13);
         ckBox.Location = new Point(rect.Location.X + dgvList.Columns[0].Width / 2 - 13 / 2 - 1, rect.Location.Y + 3);
         ckBox.CheckedChanged += new EventHandler(CheckBox_CheckedChanged);
         dgvList.Controls.Add(ckBox);
}

/// <summary>
/// 改變勾選狀態時
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void CheckBox_CheckedChanged(object sender, EventArgs e)
{
        for (int i = 0; i < dgvList.Rows.Count; i++)
        {
             dgvList.Rows[i].Cells["colIsCheck"].Value = ((CheckBox)sender).Checked;
         }
         dgvList.EndEdit();
}

[C#]讓電腦主機板喇叭發出聲音提示

//API功能 Beep參考、設定
[DllImport("kernel32.dll")]
private static extern int Beep(int dwFreq, int dwDuration);
public enum Music
{
      Do = 523,
      Re = 587,
      Mi = 659,
      Fa = 698,
      So = 784,
      La = 880,
      Ti = 988,
      Do2 = 1046
};

/// <summary>
/// Beep事件
/// </summary>
private void Beep()
{
      Beep((int)Music.Do, 300);
      Beep((int)Music.Re, 300);
      Beep((int)Music.Mi, 300);
      Beep((int)Music.Fa, 300);
      Beep((int)Music.So, 300);
      Beep((int)Music.La, 300);
      Beep((int)Music.Ti, 300);
      Beep((int)Music.Do2, 300);
}

[C#]讀取XML轉換成DataTable

[C#]計算時間差(範例為計算分鐘)

TimeSpan ts;
DateTime d1;
DateTime d2;
ts = d1 - d2;
double dMinutes = ts.TotalMinutes;

[C#]限制TextBox只能輸入數字

private void TextBox_KeyPress(object sender, KeyPressEventArgs e)
{
     if (!char.IsDigit(e.KeyChar) && !char.IsControl(e.KeyChar))
     {
          e.Handled = true;
      }
 }

[C#]NPOI匯出Excel檔

先到 NPOI官方：http://npoi.codeplex.com/ 下載dll檔

        using NPOI.Util;
        using NPOI.HSSF.Model;
        using NPOI.HSSF.UserModel;
        using NPOI.HSSF;

        /// <summary>
        /// DataTable轉換成Excel檔
        /// </summary>
        /// <param name="dt">DataTable</param>
        /// <param name="xlsSaveFileName">儲存路徑</param>
        /// <returns></returns>
        private bool ConvertToExcel(DataTable dt, string xlsSaveFileName)
        {
            //新増Excel檔案
            FileStream fs = new FileStream(xlsSaveFileName, FileMode.Create);
            try
            {
                HSSFWorkbook newBook = new HSSFWorkbook();
                //新増Sheet
                HSSFSheet newSheet = (HSSFSheet)newBook.CreateSheet("匯出檔");

[C#]移除字串中非數字的字元

using System.Text.RegularExpressions;


string Str2 = Regex.Replace(Str1, "[^0-9]", "");