重新想象 Windows 8 Store Apps (9) - 控件之 ScrollViewer 基础
作者:介绍重新想象 Windows 8 Store Apps 之 ScrollViewer - 演示 ScrollViewer 的基本应用
- 演示 ScrollBar 的基本应用
- 演示 ScrollContentPresenter 的基本应用
ScrollViewer/Demo.xaml.cs
/* * ScrollViewer - 滚动视图控件 * * 本例用于演示 ScrollViewer 的基本用法 */using Windows.UI.Xaml;using Windows.UI.Xaml.Controls;namespace XamlDemo.Controls.ScrollViewer{ public sealed partial class Demo : Page { public Demo() { this.InitializeComponent(); } private void scrollViewer_ViewChanged_1(object sender, ScrollViewerViewChangedEventArgs e) { lblMsg.Text = ""; /* * ScrollViewer - 滚动视图控件 * ComputedHorizontalScrollBarVisibility - 当前水平滚动条的可见性,比如当 HorizontalScrollBarVisibility 设置为 Auton 时,可以通过 ComputedHorizontalScrollBarVisibility 来判断当前水平滚动条是否可见 * ComputedVerticalScrollBarVisibility - 当前垂直滚动条的可见性 * ExtentWidth - ScrollViewer 内的内容的宽 * ExtentHeight - ScrollViewer 内的内容的高 * ViewportWidth - 可视区的宽 * ViewportHeight - 可视区的高 * HorizontalOffset - 滚动内容的水平方向的偏移量 * VerticalOffset - 滚动内容的垂直方向的偏移量 * ScrollableWidth - 可滚动区域的水平方向的大小 * ScrollableHeight - 可滚动区域的垂直方向的大小 * * ScrollToHorizontalOffset() - 滚动到指定的水平偏移位置 * ScrollToVerticalOffset() - 滚动到指定的垂直偏移位置 */ lblMsg.Text += "ComputedHorizontalScrollBarVisibility: " + scrollViewer.ComputedHorizontalScrollBarVisibility; lblMsg.Text += "\r\n"; lblMsg.Text += "ComputedVerticalScrollBarVisibility: " + scrollViewer.ComputedVerticalScrollBarVisibility; lblMsg.Text += "\r\n"; lblMsg.Text += "ExtentWidth: " + scrollViewer.ExtentWidth; lblMsg.Text += "\r\n"; lblMsg.Text += "ExtentHeight: " + scrollViewer.ExtentHeight; lblMsg.Text += "\r\n"; lblMsg.Text += "ViewportWidth: " + scrollViewer.ViewportWidth; lblMsg.Text += "\r\n"; lblMsg.Text += "ViewportHeight: " + scrollViewer.ViewportHeight; lblMsg.Text += "\r\n"; lblMsg.Text += "HorizontalOffset: " + scrollViewer.HorizontalOffset; lblMsg.Text += "\r\n"; lblMsg.Text += "VerticalOffset: " + scrollViewer.VerticalOffset; lblMsg.Text += "\r\n"; lblMsg.Text += "ScrollableWidth: " + scrollViewer.ScrollableWidth; lblMsg.Text += "\r\n"; lblMsg.Text += "ScrollableHeight: " + scrollViewer.ScrollableHeight; lblMsg.Text += "\r\n"; } private void Button_Click_1(object sender, RoutedEventArgs e) { scrollViewer.ScrollToHorizontalOffset(scrollViewer.ScrollableWidth / 2); scrollViewer.ScrollToVerticalOffset(scrollViewer.ScrollableHeight / 2); } }}
ScrollViewer/ScrollBarDemo.xaml.cs
/* * ScrollBar - 滚动条控件 * * 本例通过访问 ScrollViewer 内的名为 VerticalScrollBar 的 ScrollBar 控件,来简要说明 ScrollBar 控件 */using Windows.UI.Xaml;using Windows.UI.Xaml.Controls;using Windows.UI.Xaml.Controls.Primitives;using XamlDemo.Common;namespace XamlDemo.Controls.ScrollViewer{ public sealed partial class ScrollBarDemo : Page { public ScrollBarDemo() { this.InitializeComponent(); this.Loaded += ScrollBarDemo_Loaded; } void ScrollBarDemo_Loaded(object sender, RoutedEventArgs e) { // 找到 ScrollViewer 内的名为 VerticalScrollBar 的 ScrollBar 控件,即 ScrollViewer 内的垂直滚动条 var scrollBar = Helper.GetVisualChild(scrollViewer, "VerticalScrollBar"); // ValueChanged - 当滚动条的值发生改变是所触发的事件 scrollBar.ValueChanged += scrollBar_ValueChanged; } void scrollBar_ValueChanged(object sender, RangeBaseValueChangedEventArgs e) { // 显示垂直滚动条的当前值 lblMsg.Text = e.NewValue.ToString(); } }}
ScrollViewer/ScrollContentPresenterDemo.xaml.cs
/* * ScrollContentPresenter - ScrollViewer 的内容呈现器(类似的有 ContentPresenter, ItemsPresenter) * * ScrollContentPresenter 用来呈现 ScrollViewer 的 Content */using Windows.UI.Xaml;using Windows.UI.Xaml.Controls;using XamlDemo.Common;namespace XamlDemo.Controls.ScrollViewer{ public sealed partial class ScrollContentPresenterDemo : Page { public ScrollContentPresenterDemo() { this.InitializeComponent(); this.Loaded += ScrollContentPresenterDemo_Loaded; } void ScrollContentPresenterDemo_Loaded(object sender, RoutedEventArgs e) { // 找到 ScrollViewer 内的名为 ScrollContentPresenter 的 ScrollContentPresenter 控件 var scrollContentPresenter = Helper.GetVisualChild(scrollViewer, "ScrollContentPresenter"); scrollContentPresenter.Margin = new Thickness(100); } }}