<ScrollViewer Width="" Height="" BorderBrush="Brown" BorderThickness="" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto">

            <TextBlock x:Name="_txtb" Background="HotPink" TextWrapping="Wrap" Foreground="Wheat"/>

        </ScrollViewer>

_txtb.Text = "1\r\n7\r\n6\r\n5dsaadsfjhduhtndsadjdhsajhscadsadsadas哈哈哈你\r\n4\r\n3\r\n2\r\n1\r\n0\r\n1\r\n2";

        public MainWindow()
　　　　　{

            InitializeComponent();

            var outer = new ScrollViewer();

            outer.Background = Brushes.Gray;

            outer.Width = ;

            outer.Height = ;

            var inner = new TextBlock();

            inner.Background = Brushes.Orange;

            inner.Foreground = Brushes.White;

            inner.Width = ;

            outer.Content = inner;

            outer.MaxHeight = ;

            inner.Text = "1\r\n7\r\n6\r\n5dsaadsfjhduhtndsadjdhsajhscadsadsadas哈哈哈你\r\n4\r\n3\r\n2\r\n1\r\n0\r\n1\r\n2";

            // 此行用于文本内容根据设定宽度，当一行过长时自动换行

            // inner.TextWrapping = TextWrapping.Wrap;

            outer.VerticalScrollBarVisibility = ScrollBarVisibility.Auto;

            outer.HorizontalScrollBarVisibility = ScrollBarVisibility.Auto;

            // 此句慎用呀，此处主要为了在界面上显示出结果

            this.Content = outer;

        }