Windows 8技巧：关于windows 8的文件管理 File创建和String Stream Buffer方式读写的

Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}">
!--显示区-->
TextBlock HorizontalAlignment="Left" Margin="137,42,0,0" TextWrapping="Wrap" Text="文件名:"
VerticalAlignment="Top" Height="23" Width="43"/>
TextBox HorizontalAlignment="Left" Margin="185,33,0,0" TextWrapping="Wrap"
Text="test.txt" VerticalAlignment="Top" Width="121" Name="tbFileName"/>
TextBox HorizontalAlignment="Left" Margin="457,33,0,0" TextWrapping="Wrap"
Text="默认需要添加的文件内容" VerticalAlignment="Top" Width="431" Name="tbContent"/>
TextBlock HorizontalAlignment="Left" Margin="396,42,0,0" TextWrapping="Wrap" Text="文件内容："
VerticalAlignment="Top" Height="23" Width="61"/>
TextBlock HorizontalAlignment="Left" Margin="127,317,0,0" TextWrapping="Wrap" Text="提示："
VerticalAlignment="Top" Height="23" Width="761" Name="tb_show"/>
!--创建文件以及普通string写入读取文本-->
Button Content="创建文件" HorizontalAlignment="Left" Margin="127,99,0,0"
Name="btnCreateFile" VerticalAlignment="Top" Click="btnCreateFile_Click"/>
Button Content="写入string文件" HorizontalAlignment="Left" Margin="430,99,0,0"
x:Name="btnWriteFile_Copy" VerticalAlignment="Top" Click="btnWriteFile_Copy_Click"/>
Button Content="读取string文件" HorizontalAlignment="Left" Margin="757,99,0,0"
x:Name="btnReadFile" VerticalAlignment="Top" Click="btnReadFile_Click"/>
!--Buffer方式写入和读取-->
Button Content="写入Buffer数据" HorizontalAlignment="Left" Margin="127,173,0,0"
x:Name="btnWriteBufferFile" VerticalAlignment="Top" Click="btnWriteBufferFile_Click" />
Button Content="读取Buffer数据" HorizontalAlignment="Left" Margin="754,173,0,0"
x:Name="btnReadBufferFile" VerticalAlignment="Top" Click="btnReadBufferFile_Click"/>
!--Stream方式写入和读取-->
Button Content="写入Stream数据" HorizontalAlignment="Left" Margin="127,243,0,0"
x:Name="btnWriteStreamFile" VerticalAlignment="Top" Click="btnWriteStreamFile_Click" />
Button Content="读取Stream数据" HorizontalAlignment="Left" Margin="748,243,0,0"
x:Name="btnReadStreamFile" VerticalAlignment="Top" Click="btnReadStreamFile_Click"/>
/Grid>

/// summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// /summary>
public sealed partial class MainPage : Page
{/p> p> public MainPage()
{
this.InitializeComponent();
}/p> p> /// summary>
/// Invoked when this page is about to be displayed in a Frame.
/// /summary>
/// param name="e">Event data that describes how this page was reached. The Parameter
/// property is typically used to configure the page./param>
protected override void OnNavigatedTo(NavigationEventArgs e)
{
}/p> p> //获取“库\文档”文件夹
StorageFolder storageFolder = KnownFolders.DocumentsLibrary;/p> p> //创建文件以及普通string写入读取文本
private async void btnCreateFile_Click(object sender, RoutedEventArgs e)
{
StorageFile sf= await storageFolder.CreateFileAsync(this.tbFileName.Text.Trim(),
CreationCollisionOption.ReplaceExisting);
tb_show.Text = "提示:创建了文件--" + this.tbFileName.Text.Trim();
}/p> p> private async void btnWriteFile_Copy_Click(object sender, RoutedEventArgs e)
{
try
{
string writestr = this.tbContent.Text.Trim() + "text方式";
StorageFile sf = await storageFolder.GetFileAsync(this.tbFileName.Text.Trim());
await FileIO.WriteTextAsync(sf, writestr);
tb_show.Text = "提示:文件写入成功，写入内容为-“" + writestr + "”";
}
catch (Exception ex)
{
tb_show.Text = "提示:未找到该文件，请先创建文件";
}
}/p> p> private async void btnReadFile_Click(object sender, RoutedEventArgs e)
{
try
{
StorageFile sf = await storageFolder.GetFileAsync(this.tbFileName.Text.Trim());
string filecontent= await FileIO.ReadTextAsync(sf,UnicodeEncoding.Utf8);
tb_show.Text = "提示:文件以string方式读取成功，读取的内容为-“" + filecontent+"”";
}
catch (Exception ex)
{
tb_show.Text = "提示:未找到该文件，请先创建文件";
}
}
//Buffer方式写入和读取
private async void btnWriteBufferFile_Click(object sender, RoutedEventArgs e)
{
try
{
string writestr = this.tbContent.Text.Trim() + "buffer方式";
StorageFile sf = await storageFolder.GetFileAsync(this.tbFileName.Text.Trim());
IBuffer buffer = GetBufferFromString(writestr);
await FileIO.WriteBufferAsync(sf, buffer);
tb_show.Text = "提示:文件写入成功，写入内容为-“" + writestr + "”";
}
catch (Exception ex)
{
tb_show.Text = "提示:未找到该文件，请先创建文件";
}
}/p> p> private async void btnReadBufferFile_Click(object sender, RoutedEventArgs e)
{
StorageFile sf = await storageFolder.GetFileAsync(this.tbFileName.Text.Trim());
IBuffer buffer = await FileIO.ReadBufferAsync(sf);
using (DataReader dataReader = DataReader.FromBuffer(buffer))
{
string filecontent = dataReader.ReadString(buffer.Length);
tb_show.Text = "提示:文件以Buffer方式读取成功，读取的内容为-“" + filecontent + "”";
}
}/p> p> //将String转为Buffer
private IBuffer GetBufferFromString(String str)
{
using (InMemoryRandomAccessStream memoryStream = new InMemoryRandomAccessStream())
{
using (DataWriter dataWriter = new DataWriter(memoryStream))
{
dataWriter.WriteString(str);
return dataWriter.DetachBuffer();
}
}
}/p> p> //Stream方式写入和读取
private async void btnWriteStreamFile_Click(object sender, RoutedEventArgs e)
{
try
{
string writestr = this.tbContent.Text.Trim() + "Stream方式";
StorageFile sf = await storageFolder.GetFileAsync(this.tbFileName.Text.Trim());
using (StorageStreamTransaction transaction = await sf.OpenTransactedWriteAsync())
{
using (DataWriter dataWriter = new DataWriter(transaction.Stream))
{
dataWriter.WriteString(writestr);
transaction.Stream.Size = await dataWriter.StoreAsync(); // reset stream size to override the file
await transaction.CommitAsync();
tb_show.Text = "提示:文件写入成功，写入内容为-“" + writestr + "”";
}
}
}
catch (Exception ex)
{
tb_show.Text = "提示:未找到该文件，请先创建文件";
}

}/p> p> private async void btnReadStreamFile_Click(object sender, RoutedEventArgs e)
{
StorageFile sf = await storageFolder.GetFileAsync(this.tbFileName.Text.Trim());
using (IRandomAccessStream readStream = await sf.OpenAsync(FileAccessMode.Read))
{
using (DataReader dataReader = new DataReader(readStream))
{
UInt64 size = readStream.Size;
if (size = UInt32.MaxValue)
{
UInt32 numBytesLoaded = await dataReader.LoadAsync((UInt32)size);
string filecontent = dataReader.ReadString(numBytesLoaded);
tb_show.Text = "提示:文件以Stream方式读取成功，读取的内容为-“" + filecontent + "”";
}
}
}
}
}