public frmDiffString() { InitializeComponent(); frmDiff = this; }
private void tsbDiffString_Click(object sender, RoutedEventArgs e) { if(frmDiffString.frmDiff == null) { frmDiffString frmDiff = new frmDiffString(); frmDiff.WindowState = WindowState.Maximized; frmDiff.Show(); } else { frmDiffString.frmDiff.WindowState = WindowState.Maximized; frmDiffString.frmDiff.Show(); } }