重新想象 Windows 8 Store Apps (40)

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重新想象 Windows 8 Store Apps (40) - 剪切板: 复制/粘贴文本, html, 图片, 文件

作者：webabcd


介绍
重新想象 Windows 8 Store Apps 之 剪切板

• Clipboard - 剪切板
• 复制/粘贴文本
• 复制/粘贴html
• 复制/粘贴图片
• 复制/粘贴文件

示例
1、演示剪切板的基本应用
Clipboard/Demo.xaml

<Page
    x:Class="XamlDemo.Clipboard.Demo"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:XamlDemo.Clipboard"
    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">

            <TextBlock Name="lblMsg" FontSize="14.667" />

            <Button Name="btnCopyText" Content="复制一段文本到剪切板" Click="btnCopyText_Click_1" Margin="0 10 0 0" />

            <Button Name="btnPasteText" Content="粘贴剪切板中的文本" Click="btnPasteText_Click_1" Margin="0 10 0 0" />

            <Button Name="btnShowAvailableFormats" Content="获取剪切板中包含的数据的格式类型" Click="btnShowAvailableFormats_Click_1" Margin="0 10 0 0" />
            
            <Button Name="btnClear" Content="清除剪切板中的全部内容" Click="btnClear_Click_1" Margin="0 10 0 0" />

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

Clipboard/Demo.xaml.cs

/*
 * Clipboard - 剪切板
 *     SetContent() - 将指定的 DataPackage 存入剪切板
 *     GetContent() - 从剪切板中获取 DataPackage 对象
 *     Clear() - 清除剪切板中的全部数据
 *     Flush() - 正常情况下，关闭 app 后，此 app 保存到剪切板的数据就会消失；调用此方法后，即使关闭 app，剪切板中的数据也不会消失
 *     ContentChanged - 剪切板中的数据发生变化时所触发的事件
 *     
 * DataPackage - 用于封装 Clipboard 或 ShareContract 的数据（详细说明见 ShareContract 的 Demo）
 *     SetText(), SetUri(), SetHtmlFormat(), SetRtf(), SetBitmap(), SetStorageItems(), SetData(), SetDataProvider() - 设置复制到剪切板的各种格式的数据（注：一个 DataPackage 可以有多种不同格式的数据）
 *     RequestedOperation - 操作类型（DataPackageOperation 枚举: None, Copy, Move, Link），没发现此属性有任何作用
 *     
 * DataPackageView - DataPackage 对象的只读版本，从剪切板获取数据或者共享目标接收数据均通过此对象来获取 DataPackage 对象的数据（详细说明见 ShareContract 的 Demo）
 */

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

namespace XamlDemo.Clipboard
{
    public sealed partial class Demo : Page
    {
        public Demo()
        {
            this.InitializeComponent();
        }

        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            Windows.ApplicationModel.DataTransfer.Clipboard.ContentChanged += Clipboard_ContentChanged;
        }

        protected override void OnNavigatedFrom(NavigationEventArgs e)
        {
            Windows.ApplicationModel.DataTransfer.Clipboard.ContentChanged -= Clipboard_ContentChanged;
        }

        void Clipboard_ContentChanged(object sender, object e)
        {
            lblMsg.Text += Environment.NewLine;
            lblMsg.Text += "剪切板中的内容发生了变化";
        }

        // 复制一段文本到剪切板
        private void btnCopyText_Click_1(object sender, RoutedEventArgs e)
        {
            // 构造保存到剪切板的 DataPackage 对象
            DataPackage dataPackage = new DataPackage();
            dataPackage.SetText("I am webabcd: " + DateTime.Now.ToString());

            try
            {
                Windows.ApplicationModel.DataTransfer.Clipboard.SetContent(dataPackage); // 保存 DataPackage 对象到剪切板
                Windows.ApplicationModel.DataTransfer.Clipboard.Flush(); // 当此 app 关闭后，依然保留剪切板中的数据
                lblMsg.Text = "已将内容复制到剪切板";
            }
            catch (Exception ex)
            {
                lblMsg.Text = ex.ToString();
            }
        }

        // 显示剪切板中的文本数据
        private async void btnPasteText_Click_1(object sender, RoutedEventArgs e)
        {
            // 获取剪切板中的数据
            DataPackageView dataPackageView = Windows.ApplicationModel.DataTransfer.Clipboard.GetContent();

            // 如果剪切板中有文本数据，则获取并显示该文本
            if (dataPackageView.Contains(StandardDataFormats.Text))
            {
                try
                {
                    string text = await dataPackageView.GetTextAsync();
                    lblMsg.Text = text;
                }
                catch (Exception ex)
                {
                    lblMsg.Text = ex.ToString();
                }
            }
            else
            {
                lblMsg.Text = "剪切板中无文本内容";
            }
        }

        // 显示剪切板中包含的数据的格式类型，可能会有 StandardDataFormats 枚举的格式，也可能会有自定义的格式（关于自定义格式可以参见：ShareContract 的 Demo）
        private void btnShowAvailableFormats_Click_1(object sender, RoutedEventArgs e)
        {
            DataPackageView dataPackageView = Windows.ApplicationModel.DataTransfer.Clipboard.GetContent();
            if (dataPackageView != null && dataPackageView.AvailableFormats.Count > 0)
            {
                var availableFormats = dataPackageView.AvailableFormats.GetEnumerator();
                while (availableFormats.MoveNext())
                {
                    lblMsg.Text += Environment.NewLine;
                    lblMsg.Text += availableFormats.Current;
                }
            }
            else
            {
                lblMsg.Text = "剪切板中无任何内容";
            }
        }

        // 清除剪切板中的全部数据
        private void btnClear_Click_1(object sender, RoutedEventArgs e)
        {
            Windows.ApplicationModel.DataTransfer.Clipboard.Clear();
        }
    }
}

2、演示如何复制 html 数据到剪切板，以及如何从剪切板中获取 html 数据 
Clipboard/CopyHtml.xaml

<Page
    x:Class="XamlDemo.Clipboard.CopyHtml"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:XamlDemo.Clipboard"
    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">

            <TextBlock Name="lblMsg" FontSize="14.667" />

            <Button Name="btnCopyHtml" Content="复制一段 html 到剪切板" Click="btnCopyHtml_Click_1" Margin="0 10 0 0" />

            <Button Name="btnPasteHtml" Content="粘贴剪切板中的 html" Click="btnPasteHtml_Click_1" Margin="0 10 0 0" />

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

Clipboard/CopyHtml.xaml.cs

/*
 * 演示如何复制 html 数据到剪切板，以及如何从剪切板中获取 html 数据 
 * 
 * HtmlFormatHelper - 在 Clipboard 中传递 html 数据或在 ShareContract 中传递 html 数据时的帮助类
 *     CreateHtmlFormat() - 封装需要传递的 html 字符串，以便以 html 方式传递数据
 *     GetStaticFragment() - 解封装传递过来的经过封装的 html 数据，从而获取初始需要传递的 html 字符串
 */

using System;
using Windows.ApplicationModel.DataTransfer;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

namespace XamlDemo.Clipboard
{
    public sealed partial class CopyHtml : Page
    {
        public CopyHtml()
        {
            this.InitializeComponent();
        }

        // 复制 html 字符串到剪切板
        private void btnCopyHtml_Click_1(object sender, RoutedEventArgs e)
        {
            DataPackage dataPackage = new DataPackage();
            // 封装一下需要复制的 html 数据，以便以 html 的方式将数据复制到剪切板
            string htmlFormat = HtmlFormatHelper.CreateHtmlFormat("<body>I am webabcd</body>");
            dataPackage.SetHtmlFormat(htmlFormat);

            try
            {
                Windows.ApplicationModel.DataTransfer.Clipboard.SetContent(dataPackage);
                lblMsg.Text = "已将内容复制到剪切板";
            }
            catch (Exception ex)
            {
                lblMsg.Text = ex.ToString();
            }
        }

        // 显示剪切板中的 html 数据
        private async void btnPasteHtml_Click_1(object sender, RoutedEventArgs e)
        {
            DataPackageView dataPackageView = Windows.ApplicationModel.DataTransfer.Clipboard.GetContent();

            if (dataPackageView.Contains(StandardDataFormats.Html))
            {
                try
                {
                    // 封装后的数据
                    string htmlFormat = await dataPackageView.GetHtmlFormatAsync();
                    // 封装前的数据
                    string htmlFragment = HtmlFormatHelper.GetStaticFragment(htmlFormat);

                    lblMsg.Text = "htmlFormat(封装后的数据): ";
                    lblMsg.Text += Environment.NewLine;
                    lblMsg.Text += htmlFormat;
                    lblMsg.Text += Environment.NewLine;
                    lblMsg.Text += Environment.NewLine;
                    lblMsg.Text += "htmlFragment(封装前的数据): ";
                    lblMsg.Text += Environment.NewLine;
                    lblMsg.Text += htmlFragment;
                }
                catch (Exception ex)
                {
                    lblMsg.Text = ex.ToString();
                }
            }
            else
            {
                lblMsg.Text = "剪切板中无 html 内容";
            }
        }
    }
}

3、演示如何复制图片内容剪切板，以及如何从剪切板中获取图片内容，以及数据的延迟复制
Clipboard/CopyImage.xaml

<Page
    x:Class="XamlDemo.Clipboard.CopyImage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:XamlDemo.Clipboard"
    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">

            <TextBlock Name="lblMsg" FontSize="14.667" />
            <Image Name="imgBitmap" Stretch="None" HorizontalAlignment="Left" Margin="0 10 0 0" />

            <Button Name="btnCopyImage" Content="复制图片内容到剪切板" Click="btnCopyImage_Click_1" Margin="0 10 0 0" />

            <Button Name="btnCopyImageWithDeferral" Content="复制数据提供器到剪切板，当“粘贴”操作被触发时由数据提供器生成用于粘贴的图片数据" Click="btnCopyImageWithDeferral_Click_1" Margin="0 10 0 0" />

            <Button Name="btnPasteImage" Content="粘贴剪切板中的图片内容" Click="btnPasteImage_Click_1" Margin="0 10 0 0" />
            
        </StackPanel>
    </Grid>
</Page>

Clipboard/CopyImage.xaml.cs

/*
 * 1、演示如何复制图片内容剪切板，以及如何从剪切板中获取图片内容
 * 2、演示如何通过 SetDataProvider() 延迟数据的复制，即在“粘贴”操作触发后由数据提供器生成相关数据
 */

using System;
using Windows.ApplicationModel.DataTransfer;
using Windows.Graphics.Imaging;
using Windows.Storage;
using Windows.Storage.Streams;
using Windows.UI.Core;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Media.Imaging;

namespace XamlDemo.Clipboard
{
    public sealed partial class CopyImage : Page
    {
        public CopyImage()
        {
            this.InitializeComponent();
        }

        // 复制图片内容到剪切板
        private void btnCopyImage_Click_1(object sender, RoutedEventArgs e)
        {
            DataPackage dataPackage = new DataPackage();
            dataPackage.SetBitmap(RandomAccessStreamReference.CreateFromUri(new Uri("ms-appx:///Assets/Logo.png", UriKind.Absolute)));

            try
            {
                Windows.ApplicationModel.DataTransfer.Clipboard.SetContent(dataPackage);
                lblMsg.Text = "已将内容复制到剪切板";
            }
            catch (Exception ex)
            {
                lblMsg.Text = ex.ToString();
            }
        }

        // 延迟复制
        private async void btnCopyImageWithDeferral_Click_1(object sender, RoutedEventArgs e)
        {
            StorageFile imageFile = await StorageFile.GetFileFromApplicationUriAsync(new Uri("ms-appx:///Assets/Logo.png", UriKind.Absolute));

            DataPackage dataPackage = new DataPackage();
            dataPackage.SetDataProvider(StandardDataFormats.Bitmap, async (request) =>
            {
                /*
                 * 当从剪切板中获取 StandardDataFormats.Bitmap 数据时，会执行到此处以提供相关数据
                 */

                if (imageFile != null)
                {
                    // 开始异步处理
                    var deferral = request.GetDeferral();

                    try
                    {
                        using (var imageStream = await imageFile.OpenAsync(FileAccessMode.Read))
                        {
                            // 将图片缩小一倍
                            BitmapDecoder imageDecoder = await BitmapDecoder.CreateAsync(imageStream);
                            var inMemoryStream = new InMemoryRandomAccessStream();
                            var imageEncoder = await BitmapEncoder.CreateForTranscodingAsync(inMemoryStream, imageDecoder);
                            imageEncoder.BitmapTransform.ScaledWidth = (uint)(imageDecoder.OrientedPixelWidth * 0.5);
                            imageEncoder.BitmapTransform.ScaledHeight = (uint)(imageDecoder.OrientedPixelHeight * 0.5);
                            await imageEncoder.FlushAsync();

                            // 指定需要复制到剪切板的数据
                            request.SetData(RandomAccessStreamReference.CreateFromStream(inMemoryStream));

                            await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
                            {
                                lblMsg.Text = "数据已生成";
                            });
                        }
                    }
                    finally
                    {
                        // 通知系统已完成异步操作
                        deferral.Complete();
                    }
                }
            });

            try
            {
                Windows.ApplicationModel.DataTransfer.Clipboard.SetContent(dataPackage);
                lblMsg.Text = "已将数据提供器复制到剪切板，在“粘贴”操作时才会生成数据";
            }
            catch (Exception ex)
            {
                lblMsg.Text = ex.ToString();
            }
        }

        // 显示剪切板中的图片内容
        private async void btnPasteImage_Click_1(object sender, RoutedEventArgs e)
        {
            DataPackageView dataPackageView = Windows.ApplicationModel.DataTransfer.Clipboard.GetContent();

            if (dataPackageView.Contains(StandardDataFormats.Bitmap))
            {
                try
                {
                    IRandomAccessStreamReference randomStream = await dataPackageView.GetBitmapAsync();
                    if (randomStream != null)
                    {
                        using (IRandomAccessStreamWithContentType imageStream = await randomStream.OpenReadAsync())
                        {
                            BitmapImage bitmapImage = new BitmapImage();
                            bitmapImage.SetSource(imageStream);
                            imgBitmap.Source = bitmapImage;
                        }
                    }
                }
                catch (Exception ex)
                {
                    lblMsg.Text = ex.ToString();
                }
            }
            else
            {
                lblMsg.Text = "剪切板中无 bitmap 内容";
            }
        }
    }
}

4、演示如何复制指定的文件到剪切板，以及如何从剪切板中获取文件并保存到指定的路径
Clipboard/CopyFile.xaml

<Page
    x:Class="XamlDemo.Clipboard.CopyFile"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:XamlDemo.Clipboard"
    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">

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

            <Button Name="btnCopyFile" Content="复制一个文件到剪切板" Click="btnCopyFile_Click_1" Margin="0 10 0 0" />

            <Button Name="btnPasteFile" Content="粘贴剪切板中的文件到指定的路径" Click="btnPasteFile_Click_1" Margin="0 10 0 0" />

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

Clipboard/CopyFile.xaml.cs

/*
 * 演示如何复制指定的文件到剪切板，以及如何从剪切板中获取文件并保存到指定的路径 
 */

using System;
using System.Linq;
using System.Collections.Generic;
using Windows.ApplicationModel.DataTransfer;
using Windows.Storage;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

namespace XamlDemo.Clipboard
{
    public sealed partial class CopyFile : Page
    {
        public CopyFile()
        {
            this.InitializeComponent();
        }

        // 保存文件到剪切板
        private async void btnCopyFile_Click_1(object sender, RoutedEventArgs e)
        {
            StorageFile file = await ApplicationData.Current.LocalFolder.CreateFileAsync(@"webabcdTestclipboard.txt", CreationCollisionOption.ReplaceExisting);
            await FileIO.WriteTextAsync(file, "I am webabcd: " + DateTime.Now.ToString());

            DataPackage dataPackage = new DataPackage();
            dataPackage.SetStorageItems(new List<StorageFile>() { file });

            dataPackage.RequestedOperation = DataPackageOperation.Move;
            try
            {
                Windows.ApplicationModel.DataTransfer.Clipboard.SetContent(dataPackage);
                lblMsg.Text = "已将文件复制到剪切板";
            }
            catch (Exception ex)
            {
                lblMsg.Text = ex.ToString();
            }
        }

        // 从剪切板中获取文件并保存到指定的路径 
        private async void btnPasteFile_Click_1(object sender, RoutedEventArgs e)
        {
            DataPackageView dataPackageView = Windows.ApplicationModel.DataTransfer.Clipboard.GetContent();

            if (dataPackageView.Contains(StandardDataFormats.StorageItems))
            {
                try
                {
                    IReadOnlyList<IStorageItem> storageItems = await dataPackageView.GetStorageItemsAsync();
                    StorageFile file = storageItems.First() as StorageFile;
                    if (file != null)
                    {
                        StorageFile newFile = await file.CopyAsync(ApplicationData.Current.TemporaryFolder, file.Name, NameCollisionOption.ReplaceExisting);
                        if (newFile != null)
                        {
                            lblMsg.Text = string.Format("已将文件从{0}复制到{1}", file.Path, newFile.Path);
                        }
                    }
                }
                catch (Exception ex)
                {
                    lblMsg.Text = ex.ToString();
                }
            }
            else
            {
                lblMsg.Text = "剪切板中无 StorageItems 内容";
            }
        }
    }
}

OK
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