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重新想象 Windows 8.1 Store Apps (79) - 控件增强: MediaElement, Frame

Posted on 2014-06-12 12:36 webabcd 阅读(...) 评论(...) 编辑 收藏

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重新想象 Windows 8.1 Store Apps (79) - 控件增强: MediaElement, Frame



作者:webabcd


介绍
重新想象 Windows 8.1 Store Apps 之控件增强

  • MediaElement - 播放视频或音频的控件
  • Frame - 框架控件,用于导航内容



示例
1、演示 MediaElement 的新特性
MediaElementDemo.xaml

<Page
    x:Class="Windows81.Controls.MediaElementDemo"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Windows81.Controls"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Grid Background="Transparent">
        <StackPanel Margin="120 0 0 0">

            <!--
                MediaElement - 播放视频或音频的控件
                    AreTransportControlsEnabled - 是否显示默认控制条
                    IsFullWindow - 是否全屏显示播放器
            -->
            
            <MediaElement Name="mediaElement" Source="http://media.w3.org/2010/05/sintel/trailer.mp4" Width="400" Height="300" HorizontalAlignment="Left"
                          AreTransportControlsEnabled="True" />
            
            <Button Name="btnFullScreen" Content="全屏播放" Click="btnFullScreen_Click" Margin="0 10 0 0" />

        </StackPanel>
    </Grid>
</Page>

MediaElementDemo.xaml.cs

/*
 * MediaElement - 播放视频或音频的控件
 *     AreTransportControlsEnabled - 是否显示默认控制条(win8.1 新增)
 *     IsFullWindow - 是否全屏显示播放器(win8.1 新增)
 *     
 * 
 * 关于 MediaElement 的基础请参见:http://www.cnblogs.com/webabcd/archive/2013/01/24/2874156.html
 * 
 * 
 * 注:在 win8.1 中已经引入 MediaStreamSource 了
 */

using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

namespace Windows81.Controls
{
    public sealed partial class MediaElementDemo : Page
    {
        public MediaElementDemo()
        {
            this.InitializeComponent();
        }

        private void btnFullScreen_Click(object sender, RoutedEventArgs e)
        {
            mediaElement.IsFullWindow = true;
        }
    }
}


2、完整说明 win8 frame 的功能,并介绍 win8.1 frame 中的新增功能
Frame/Demo.xaml

<Page
    x:Class="Windows81.Controls.Frame.Demo"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:Windows81.Controls.Frame"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d">

    <Grid Background="Transparent">
        <StackPanel Margin="120 0 0 0" Orientation="Horizontal">

            <StackPanel Width="400">
                <Button Name="btnGotoFrame1" Content="导航至 Frame1" Click="btnGotoFrame1_Click_1" />

                <Button Name="btnGotoFrame2" Content="导航至 Frame2" Click="btnGotoFrame2_Click_1" Margin="0 10 0 0" />

                <Button Name="btnBack" Content="后退" Click="btnBack_Click_1" Margin="0 10 0 0" />

                <Button Name="btnForward" Content="前进" Click="btnForward_Click_1" Margin="0 10 0 0" />

                <TextBlock Name="lblMsg" FontSize="14.667" TextWrapping="Wrap" Margin="0 10 0 0" />
            </StackPanel>

            <Frame Name="frame" VerticalAlignment="Top" Margin="10 0 0 0"  />

        </StackPanel>
    </Grid>
</Page>

Frame/Demo.xaml.cs

/*
 * 本例会完整说明 win8 frame 的功能,并介绍 win8.1 frame 中的新增功能
 * 
 * 
 * Frame - 框架控件,用于导航内容
 *     BackStackDepth - 返回 stack 中的条目数
 *     BackStack - 返回 stack 集合,一个 PageStackEntry 集合,可以添加或删除返回 stack 集合中的元素(win8.1 新增)
 *     ForwardStack - 前进 stack 集合,一个 PageStackEntry 集合,可以添加或删除前进 stack 集合中的元素(win8.1 新增)
 *     CanGoBack - 可否向后导航
 *     CanGoForward - 可否向前导航
 *     GoBack() - 向后导航
 *     GoForward() - 向前导航
 *     Navigate() - 导航到指定的 Type,可以传递一个 object 类型的参数
 *     SourcePageType - 获取或设置 Frame 当前内容的 Type
 * 
 *     CacheSize - 所支持的最大缓存页数,默认值 10
 *         CacheSize 与被导航的页的 Page.NavigationCacheMode 属性相关(详见 Frame1.xaml.cs 和 Frame2.xaml.cs 的示例代码)
 *             NavigationCacheMode.Disabled - 每次导航到页时,都重新实例化此页,默认值(CacheSize 无效)
 *             NavigationCacheMode.Enabled - 每次导航到页时,首先缓存此页,此时如果已缓存的页数大于 CacheSize,则按先进先出的原则丢弃最早的缓存页(CacheSize 有效)
 *             NavigationCacheMode.Required - 每次导航到页时,都缓存此页(CacheSize 无效)
 * 
 *     Navigating - 导航开始时触发的事件
 *     Navigated - 导航完成后触发的事件
 *     NavigationFailed - 导航失败时触发的事件
 *     NavigationStopped - 导航过程中,又请求了一个新的导航时触发的事件
 *     
 *     GetNavigationState() - 获取 Frame 当前的导航状态,返回字符串类型的数据,仅当导航无参数传递或只传递简单参数(int, char, string, guid, bool 等)时有效
 *     SetNavigationState(string navigationState) - 将 Frame 还原到指定的导航状态
 *     
 * 
 * 
 * NavigationEventArgs - 导航的事件参数
 *     NavigationMode - 导航方式,只读(Windows.UI.Xaml.Navigation.NavigationMode 枚举)
 *         New, Back, Forward, Refresh
 *     Parameter - 传递给导航目标页的参数,只读
 *     SourcePageType - 导航的目标页的类型,只读
 */

using System;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace Windows81.Controls.Frame
{
    public sealed partial class Demo : Page
    {
        public Demo()
        {
            this.InitializeComponent();
        }

        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            frame.Navigated += frame_Navigated;
        }

        void frame_Navigated(object sender, NavigationEventArgs e)
        {
            lblMsg.Text = "CacheSize: " + frame.CacheSize;
            lblMsg.Text += Environment.NewLine;
            lblMsg.Text += "BackStackDepth: " + frame.BackStackDepth;
            lblMsg.Text += Environment.NewLine;
            lblMsg.Text += "CanGoBack: " + frame.CanGoBack;
            lblMsg.Text += Environment.NewLine;
            lblMsg.Text += "CanGoForward: " + frame.CanGoForward;
            lblMsg.Text += Environment.NewLine;
            lblMsg.Text += "CurrentSourcePageType: " + frame.CurrentSourcePageType;
            lblMsg.Text += Environment.NewLine;

            // 显示 frame 的当前的导航状态,记录此值后,可以在需要的时候通过 SetNavigationState() 将 frame 还原到指定的导航状态
            lblMsg.Text += "NavigationState: " + frame.GetNavigationState();
        }

        private void btnGotoFrame1_Click_1(object sender, RoutedEventArgs e)
        {
            frame.Navigate(typeof(Frame1), "param1");
        }

        private void btnGotoFrame2_Click_1(object sender, RoutedEventArgs e)
        {
            frame.SourcePageType = typeof(Frame2);
        }

        private void btnBack_Click_1(object sender, RoutedEventArgs e)
        {
            if (frame.CanGoBack)
                frame.GoBack();
        }

        private void btnForward_Click_1(object sender, RoutedEventArgs e)
        {
            if (frame.CanGoForward)
                frame.GoForward();
        }
    }
}

Frame/Frame1.xaml.cs

using System;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace Windows81.Controls.Frame
{
    public sealed partial class Frame1 : Page
    {
        public Frame1()
        {
            this.InitializeComponent();

            /*
             * Page.NavigationCacheMode - 使用 Frame 导航到此页面时,页面的缓存模式
             *     Disabled - 每次导航到页时,都重新实例化此页,默认值(Frame.CacheSize 无效)
             *     Enabled - 每次导航到页时,首先缓存此页,此时如果已缓存的页数大于 Frame.CacheSize,则按先进先出的原则丢弃最早的缓存页(Frame.CacheSize 有效)
             *     Required - 每次导航到页时,都缓存此页(Frame.CacheSize 无效)
             */
            this.NavigationCacheMode = Windows.UI.Xaml.Navigation.NavigationCacheMode.Enabled;

            this.Loaded += Frame1_Loaded;
        }

        void Frame1_Loaded(object sender, Windows.UI.Xaml.RoutedEventArgs e)
        {
            lblMsg.Text += Environment.NewLine;
            lblMsg.Text += "Loaded: " + DateTime.Now.ToString();
        }

        // 来了
        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            lblMsg.Text += Environment.NewLine;
            lblMsg.Text += "OnNavigatedTo: " + DateTime.Now.ToString();
            lblMsg.Text += " param: " + (string)e.Parameter;
        }

        // 准备走了,但是可以取消
        protected override void OnNavigatingFrom(NavigatingCancelEventArgs e)
        {
            // NavigatingCancelEventArgs.Parameter - 是 win8.1 新增的

            lblMsg.Text += Environment.NewLine;
            lblMsg.Text += "OnNavigatingFrom(NavigatingCancelEventArgs): " + DateTime.Now.ToString();
            lblMsg.Text += " param: " + (string)e.Parameter;
        }

        // 已经走了
        protected override void OnNavigatedFrom(NavigationEventArgs e)
        {
            lblMsg.Text += Environment.NewLine;
            lblMsg.Text += "OnNavigatedFrom(NavigationEventArgs): " + DateTime.Now.ToString();
            lblMsg.Text += " param: " + (string)e.Parameter;
        }
    }
}

Frame/Frame2.xaml.cs

using System;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;

namespace Windows81.Controls.Frame
{
    public sealed partial class Frame2 : Page
    {
        public Frame2()
        {
            this.InitializeComponent();

            /*
             * Page.NavigationCacheMode - 使用 Frame 导航到此页面时,页面的缓存模式
             *     Disabled - 每次导航到页时,都重新实例化此页,默认值(Frame.CacheSize 无效)
             *     Enabled - 每次导航到页时,首先缓存此页,此时如果已缓存的页数大于 Frame.CacheSize,则按先进先出的原则丢弃最早的缓存页(Frame.CacheSize 有效)
             *     Required - 每次导航到页时,都缓存此页(Frame.CacheSize 无效)
             */
            this.NavigationCacheMode = Windows.UI.Xaml.Navigation.NavigationCacheMode.Enabled;

            this.Loaded += Frame2_Loaded;
        }

        void Frame2_Loaded(object sender, Windows.UI.Xaml.RoutedEventArgs e)
        {
            lblMsg.Text += Environment.NewLine;
            lblMsg.Text += "Loaded: " + DateTime.Now.ToString();
        }

        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            lblMsg.Text += Environment.NewLine;
            lblMsg.Text += "OnNavigatedTo: " + DateTime.Now.ToString();
        }
    }
}



OK
[源码下载]