其次：設置程序允許以上文件夾內的文件類型，本實例中設置為txt后綴的文件：設置方法：點擊”Package.appxmanifest“，然后選擇”聲明“選項卡，在可用聲明下拉列表中選擇”文件類型關聯“，點擊”添加“按鈕，并且在右邊的列表中添加”支持的文件類型為.txt，并且設置名稱為txt，當然你也可以繼續添加允許訪問dat文件等，如下圖：
/// <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> //獲取“庫/文檔”文件夾
StorageFolder storageFolder = KnownFolders.DocumentsLibrary;</p><p> //創建文件以及普通string寫入讀取文本
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:創建了文件--" + 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:文件寫入成功，寫入內容為-“" + writestr + "”";
}
catch (Exception ex)
{
tb_show.Text = "提示:未找到該文件，請先創建文件";
}
}</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方式讀取成功，讀取的內容為-“" + filecontent+"”";
}
catch (Exception ex)
{
tb_show.Text = "提示:未找到該文件，請先創建文件";
}
}
//Buffer方式寫入和讀取
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:文件寫入成功，寫入內容為-“" + writestr + "”";
}
catch (Exception ex)
{
tb_show.Text = "提示:未找到該文件，請先創建文件";
}
}</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方式讀取成功，讀取的內容為-“" + filecontent + "”";
}
}</p><p> //將String轉為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方式寫入和讀取
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:文件寫入成功，寫入內容為-“" + writestr + "”";
}
}
}
catch (Exception ex)
{
tb_show.Text = "提示:未找到該文件，請先創建文件";
}
}</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方式讀取成功，讀取的內容為-“" + filecontent + "”";
}
}
}
}
}
