在C＃WPF应用程序中加载Window时如何将TextBox插入到Grid中

private void Window_Loaded(object sender, RoutedEventArgs e)
{  
    for (int i = 0; i <= 7; i++)
    {
        ColumnDefinition clDef = new ColumnDefinition();
        RowDefinition rwDef = new RowDefinition();
        clDef.MinWidth = 40;
        clDef.MaxWidth = 40;
        rwDef.MinHeight = 32;
        rwDef.MaxHeight = 32;
        grdAdtn.ColumnDefinitions.Add(clDef);
        grdAdtn.RowDefinitions.Add(rwDef);
    };
    TextBox[,] fields=new TextBox[8,8];
    for(int i=0;i<=7;i++){
        for(int j=0;j<=7;j++){
            fields[i,j]=new TextBox();
            fields[i, j].Text = "test";
            fields[i, j].Width = 40;
            fields[i, j].Height = 32;
            fields[i, j].Visibility = Visibility.Visible;
            //Grid.SetColumn(fields[i, j], i);
        }
    }
}
private void Window_Loaded(object sender, Route