重新想象Windows8StoreApps(23)文件系统:文本的读写,二进制的读写,流的读写,最近访问列表和未来访问列表...

/** 演示如何读写文本数据* 注&＃xff1a;如果需要读写某扩展名的文件&＃xff0c;需要在 Package.appxmanifest 增加“文件类型关联”声明&＃xff0c;并做相应的配置* * StorageFolder - 文件夹操作类* 获取文件夹相关属性、重命名、Create...、Get...等* * StorageFile - 文件操作类* 获取文件相关属性、重命名、Create...、Get...、Copy...、Move...、Delete...、Open...、Replace...等* * FileIO - 用于读写 IStorageFile 对象的帮助类* WriteTextAsync() - 将指定的文本数据写入到指定的文件* AppendTextAsync() - 将指定的文本数据追加到指定的文件* WriteLinesAsync() - 将指定的多行文本数据写入到指定的文件* AppendLinesAsync() - 将指定的多行文本数据追加到指定的文件* ReadTextAsync() - 获取指定的文件中的文本数据* ReadLinesAsync() - 获取指定的文件中的文本数据&＃xff0c;返回的是一行一行的数据* * 注&＃xff1a;WinRT 中的关于存储操作的相关类都在 Windows.Storage 命名空间内*/using System;
using Windows.Storage;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;namespace XamlDemo.FileSystem
{public sealed partial class ReadWriteText : Page{public ReadWriteText(){this.InitializeComponent();}private async void btnWriteText_Click_1(object sender, RoutedEventArgs e){// 在指定的目录下创建指定的文件StorageFolder storageFolder &＃61; KnownFolders.DocumentsLibrary;StorageFile storageFile &＃61; await storageFolder.CreateFileAsync("webabcdText.txt", CreationCollisionOption.ReplaceExisting);// 在指定的文件中写入指定的文本string textContent &＃61; "I am webabcd";await FileIO.WriteTextAsync(storageFile, textContent, Windows.Storage.Streams.UnicodeEncoding.Utf8);lblMsg.Text &＃61; "写入成功";}private async void btnReadText_Click_1(object sender, RoutedEventArgs e){// 在指定的目录下获取指定的文件StorageFolder storageFolder &＃61; KnownFolders.DocumentsLibrary;StorageFile storageFile &＃61; await storageFolder.GetFileAsync("webabcdText.txt");if (storageFile !&＃61; null){// 获取指定的文件中的文本内容string textContent &＃61; await FileIO.ReadTextAsync(storageFile, Windows.Storage.Streams.UnicodeEncoding.Utf8);lblMsg.Text &＃61; "读取结果&＃xff1a;" &＃43; textContent;}}}
}

/** 演示如何读写二进制数据* 注&＃xff1a;如果需要读写某扩展名的文件&＃xff0c;需要在 Package.appxmanifest 增加“文件类型关联”声明&＃xff0c;并做相应的配置* * StorageFolder - 文件夹操作类* 获取文件夹相关属性、重命名、Create...、Get...等* * StorageFile - 文件操作类* 获取文件相关属性、重命名、Create...、Get...、Copy...、Move...、Delete...、Open...、Replace...等* * FileIO - 用于读写 IStorageFile 对象的帮助类* WriteBufferAsync() - 将指定的二进制数据写入指定的文件* ReadBufferAsync() - 获取指定的文件中的二进制数据* * IBuffer - WinRT 中的字节数组* * 注&＃xff1a;WinRT 中的关于存储操作的相关类都在 Windows.Storage 命名空间内*/using System;
using Windows.Storage;
using Windows.Storage.Streams;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;namespace XamlDemo.FileSystem
{public sealed partial class ReadWriteBinary : Page{public ReadWriteBinary(){this.InitializeComponent();}private async void btnWriteBinary_Click_1(object sender, RoutedEventArgs e){// 在指定的目录下创建指定的文件StorageFolder storageFolder &＃61; KnownFolders.DocumentsLibrary;StorageFile storageFile &＃61; await storageFolder.CreateFileAsync("webabcdBinary.txt", CreationCollisionOption.ReplaceExisting);// 将字符串转换成二进制数据&＃xff0c;并保存到指定文件string textContent &＃61; "I am webabcd";IBuffer buffer &＃61; ConverterHelper.String2Buffer(textContent);await FileIO.WriteBufferAsync(storageFile, buffer);lblMsg.Text &＃61; "写入成功";}private async void btnReadBinary_Click_1(object sender, RoutedEventArgs e){// 在指定的目录下获取指定的文件StorageFolder storageFolder &＃61; KnownFolders.DocumentsLibrary;StorageFile storageFile &＃61; await storageFolder.GetFileAsync("webabcdBinary.txt");if (storageFile !&＃61; null){// 获取指定文件中的二进制数据&＃xff0c;将其转换成字符串并显示IBuffer buffer &＃61; await FileIO.ReadBufferAsync(storageFile);string textContent &＃61; ConverterHelper.Buffer2String(buffer);lblMsg.Text &＃61; "读取结果&＃xff1a;" &＃43; textContent;}}}
}

/** 演示如何读写流数据* 注&＃xff1a;如果需要读写某扩展名的文件&＃xff0c;需要在 Package.appxmanifest 增加“文件类型关联”声明&＃xff0c;并做相应的配置* * StorageFolder - 文件夹操作类* 获取文件夹相关属性、重命名、Create...、Get...等* * StorageFile - 文件操作类* 获取文件相关属性、重命名、Create...、Get...、Copy...、Move...、Delete...、Open...、Replace...等* * IBuffer - WinRT 中的字节数组* * IInputStream - 需要读取的流* IOutputStream - 需要写入的流* IRandomAccessStream - 需要读取、写入的流&＃xff0c;其继承自 IInputStream 和 IOutputStream* * DataReader - 从数据流中读取数据&＃xff0c;即从 IInputStream 读取* LoadAsync() - 从数据流中加载指定长度的数据到缓冲区* ReadInt32(), ReadByte(), ReadString() 等 - 从缓冲区中读取数据* DataWriter - 将数据写入数据流&＃xff0c;即写入 IOutputStream* WriteInt32(), WriteByte(), WriteString() 等 - 将数据写入缓冲区* StoreAsync() - 将缓冲区中的数据保存到数据流* * StorageStreamTransaction - 用于写数据流到文件的类&＃xff08;具体用法&＃xff0c;详见下面的代码&＃xff09;* Stream - 数据流&＃xff08;只读&＃xff09;* CommitAsync - 将数据流保存到文件* * 注&＃xff1a;WinRT 中的关于存储操作的相关类都在 Windows.Storage 命名空间内*/using System;
using Windows.Storage;
using Windows.Storage.Streams;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;namespace XamlDemo.FileSystem
{public sealed partial class ReadWriteStream : Page{public ReadWriteStream(){this.InitializeComponent();}private async void btnWriteStream_Click_1(object sender, RoutedEventArgs e){// 在指定的目录下创建指定的文件StorageFolder storageFolder &＃61; KnownFolders.DocumentsLibrary;StorageFile storageFile &＃61; await storageFolder.CreateFileAsync("webabcdStream.txt", CreationCollisionOption.ReplaceExisting);string textContent &＃61; "I am webabcd";using (StorageStreamTransaction transaction &＃61; await storageFile.OpenTransactedWriteAsync()){using (DataWriter dataWriter &＃61; new DataWriter(transaction.Stream)){// 将字符串写入数据流&＃xff0c;然后将数据流保存到文件
dataWriter.WriteString(textContent);transaction.Stream.Size &＃61; await dataWriter.StoreAsync();await transaction.CommitAsync();lblMsg.Text &＃61; "写入成功";}}}private async void btnReadStream_Click_1(object sender, RoutedEventArgs e){// 在指定的目录下获取指定的文件StorageFolder storageFolder &＃61; KnownFolders.DocumentsLibrary;StorageFile storageFile &＃61; await storageFolder.GetFileAsync("webabcdStream.txt");if (storageFile !&＃61; null){using (IRandomAccessStream randomStream &＃61; await storageFile.OpenAsync(FileAccessMode.Read)){using (DataReader dataReader &＃61; new DataReader(randomStream)){ulong size &＃61; randomStream.Size;if (size <&＃61; uint.MaxValue){// 获取数据流&＃xff0c;从中读取字符串值并显示uint numBytesLoaded &＃61; await dataReader.LoadAsync((uint)size);string fileContent &＃61; dataReader.ReadString(numBytesLoaded);lblMsg.Text &＃61; "读取结果&＃xff1a;" &＃43; fileContent;}}}}}}
}

<Pagex:Class&＃61;"XamlDemo.FileSystem.CacheAccess"xmlns&＃61;"http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x&＃61;"http://schemas.microsoft.com/winfx/2006/xaml"xmlns:local&＃61;"using:XamlDemo.FileSystem"xmlns:d&＃61;"http://schemas.microsoft.com/expression/blend/2008"xmlns:mc&＃61;"http://schemas.openxmlformats.org/markup-compatibility/2006"mc:Ignorable&＃61;"d"><Grid Background&＃61;"Transparent"><StackPanel Margin&＃61;"120 0 0 0"><TextBlock Name&＃61;"lblMsg" FontSize&＃61;"14.667" /><Button Name&＃61;"btnAddToMostRecentlyUsedList" Content&＃61;"AddToMostRecentlyUsedList" Click&＃61;"btnAddToMostRecentlyUsedList_Click_1" Margin&＃61;"0 10 0 0" /><Button Name&＃61;"btnGetMostRecentlyUsedList" Content&＃61;"GetMostRecentlyUsedList" Click&＃61;"btnGetMostRecentlyUsedList_Click_1" Margin&＃61;"0 10 0 0" /><Button Name&＃61;"btnAddToFutureAccessList" Content&＃61;"AddToFutureAccessList" Click&＃61;"btnAddToFutureAccessList_Click_1" Margin&＃61;"0 10 0 0" /><Button Name&＃61;"btnGetFutureAccessList" Content&＃61;"GetFutureAccessList" Click&＃61;"btnGetFutureAccessList_Click_1" Margin&＃61;"0 10 0 0" />StackPanel>Grid>
Page>

/** 演示如何读写“最近访问列表”和“未来访问列表”* 注&＃xff1a;如果需要读写某扩展名的文件&＃xff0c;需要在 Package.appxmanifest 增加“文件类型关联”声明&＃xff0c;并做相应的配置* * StorageFolder - 文件夹操作类* 获取文件夹相关属性、重命名、Create...、Get...等* * StorageFile - 文件操作类* 获取文件相关属性、重命名、Create...、Get...、Copy...、Move...、Delete...、Open...、Replace...等* * StorageApplicationPermissions - 文件/文件夹的访问列表* MostRecentlyUsedList - 最近访问列表&＃xff08;实现了 IStorageItemAccessList 接口&＃xff09;* Add(IStorageItem file, string metadata) - 添加文件或文件夹到“最近访问列表”&＃xff0c;返回 token 值&＃xff08;一个字符串类型的标识&＃xff09;&＃xff0c;通过此值可以方便地检索到对应的文件或文件夹* file - 需要添加到列表的文件或文件夹* metadata - 自定义元数据&＃xff0c;相当于上下文* AddOrReplace(string token, IStorageItem file, string metadata) - 添加文件或文件夹到“最近访问列表”&＃xff0c;如果已存在则替换* GetFileAsync(string token) - 根据 token 值&＃xff0c;在“最近访问列表”查找对应的文件* GetFolderAsync(string token) - 根据 token 值&＃xff0c;在“最近访问列表”查找对应的文件夹* GetItemAsync(string token) - 根据 token 值&＃xff0c;在“最近访问列表”查找对应的文件或文件夹* Entries - 返回 AccessListEntryView 类型的数据&＃xff0c;其是 AccessListEntry 类型数据的集合* FutureAccessList - 未来访问列表&＃xff08;实现了 IStorageItemAccessList 接口&＃xff09;* 基本用法同“MostRecentlyUsedList”* * AccessListEntry - 用于封装访问列表中的 StorageFile 或 StorageFolder 的 token 和元数据* Token - token 值* Metadata - 元数据* * 注&＃xff1a;WinRT 中的关于存储操作的相关类都在 Windows.Storage 命名空间内*/using System;
using Windows.Storage;
using Windows.Storage.AccessCache;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Navigation;namespace XamlDemo.FileSystem
{public sealed partial class CacheAccess : Page{public CacheAccess(){this.InitializeComponent();}protected async override void OnNavigatedTo(NavigationEventArgs e){// 在指定的目录下创建指定的文件StorageFolder storageFolder &＃61; KnownFolders.DocumentsLibrary;StorageFile storageFile &＃61; await storageFolder.CreateFileAsync("webabcdCacheAccess.txt", CreationCollisionOption.ReplaceExisting);// 在指定的文件中写入指定的文本string textContent &＃61; "I am webabcd";await FileIO.WriteTextAsync(storageFile, textContent, Windows.Storage.Streams.UnicodeEncoding.Utf8);}private async void btnAddToMostRecentlyUsedList_Click_1(object sender, RoutedEventArgs e){// 获取文件对象StorageFolder storageFolder &＃61; KnownFolders.DocumentsLibrary;StorageFile storageFile &＃61; await storageFolder.GetFileAsync("webabcdCacheAccess.txt");if (storageFile !&＃61; null){// 将文件添加到“最近访问列表”&＃xff0c;并获取对应的 token 值string token &＃61; StorageApplicationPermissions.MostRecentlyUsedList.Add(storageFile, storageFile.Name);lblMsg.Text &＃61; "token&＃xff1a;" &＃43; token;}}private async void btnAddToFutureAccessList_Click_1(object sender, RoutedEventArgs e){// 获取文件对象StorageFolder storageFolder &＃61; KnownFolders.DocumentsLibrary;StorageFile storageFile &＃61; await storageFolder.GetFileAsync("webabcdCacheAccess.txt");if (storageFile !&＃61; null){// 将文件添加到“未来访问列表”&＃xff0c;并获取对应的 token 值string token &＃61; StorageApplicationPermissions.FutureAccessList.Add(storageFile, storageFile.Name);lblMsg.Text &＃61; "token&＃xff1a;" &＃43; token;}}private async void btnGetMostRecentlyUsedList_Click_1(object sender, RoutedEventArgs e){AccessListEntryView entries &＃61; StorageApplicationPermissions.MostRecentlyUsedList.Entries;if (entries.Count > 0){// 通过 token 值&＃xff0c;从“最近访问列表”中获取文件对象AccessListEntry entry &＃61; entries[0];StorageFile storageFile &＃61; await StorageApplicationPermissions.MostRecentlyUsedList.GetFileAsync(entry.Token);string textContent &＃61; await FileIO.ReadTextAsync(storageFile);lblMsg.Text &＃61; "MostRecentlyUsedList 的第一个文件的文本内容&＃xff1a;" &＃43; textContent;}else{lblMsg.Text &＃61; "最近访问列表中无数据";}}private async void btnGetFutureAccessList_Click_1(object sender, RoutedEventArgs e){AccessListEntryView entries &＃61; StorageApplicationPermissions.FutureAccessList.Entries;if (entries.Count > 0){// 通过 token 值&＃xff0c;从“未来访问列表”中获取文件对象AccessListEntry entry &＃61; entries[0];StorageFile storageFile &＃61; await StorageApplicationPermissions.FutureAccessList.GetFileAsync(entry.Token);string textContent &＃61; await FileIO.ReadTextAsync(storageFile);lblMsg.Text &＃61; "FutureAccessList 的第一个文件的文本内容&＃xff1a;" &＃43; textContent;}else{lblMsg.Text &＃61; "未来访问列表中无数据";}}}
}