C#

static public TNode[] Add<TNode, T>(TNode parent, params T[] data) where TNode : TreeNode<T>, new()
{
    List<TreeNode<T>> list;

    if (parent != null)
        list = parent.Children;
    else
        list = new List<TreeNode<T>>();

    int startIndex = list.Count;
    foreach (T item in data) 
        list.Add(new TNode() { Data = item });
    
    return (TNode[])list.GetRange(startIndex, list.Count - startIndex).ToArray();
}

void btnReset_Click(object sender, EventArgs e)
{
  Application.Restart();
}

void btnReset_Click(object sender, EventArgs e)
{
    int[] n = { Left, Top, Width, Height };
    Controls.Clear();
    InitializeComponent();
    Left = n[0];
    Top = n[1];
    Width = n[2];
    Height = n[3];
}

public delegate void SetLabel(Control lblctrl, string filename);

private void setFilename(Control lblctrl, string filename)
{
    if (this.WindowState == FormWindowState.Minimized)
        return;
    if (lblctrl.InvokeRequired)
        lblctrl.BeginInvoke(new SetLabel(setFilename),
            new object[] { lblctrl, filename });
    else
        lblctrl.Text = filename;
}

foreach (string str2 in Directory.GetFiles(path))
{
    setFilename(this.lblFileName, str2);

int a=5;
int b=5;
MessageBox.Show(a==5?"a is equal to b":"a is not equal to b");

string value = GetValueFromDatabase() ?? GetValueFromConfigFile() ?? "None Selected";

SqlConnection cn = new SqlConnection("server=.;uid=sa;pwd=sa;database=Payroll1");
string ssql = "Select * from EmpDetails";
SqlDataAdapter da = new SqlDataAdapter(ssql, cn);
DataSet ds = new DataSet();

try 
{ 
cn.open();
da.Fill(ds);
BindingSource bindgrd = new BindingSource(); 
bindgrd.DataSource = ds;

if(ds.Tables[0].Rows.count > 0)
{
this.Datagridview1.DataSource = bindgrd; 
}
else
{
lblError.text = "No Rows Returned";
}
catch(SQlException ex)
{
lblError.text = ex.Message;
}
Finaly
{
cn.close();
}

SqlCommand cmd = new SqlCommand();
cmd.Connection = sqlConnection();
cmd.CommandText ="your query";
SqlDataAdapter adapter = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
adapter.Fill(ds);
datagridview1.DataSource = ds;