public async Task SaveToFileAsync(IStorageFile storageFile, string password, PasswordKeeper passwordKeeper)
{
using (var stream = await storageFile.OpenTransactedWriteAsync())
{
using (var mem = new MemoryStream(Encoding.UTF8.GetBytes(passwordKeeper.SaveToJson())))
{
EncryptAndDecrypt.Encrypt(mem, password, stream.Stream.AsStreamForWrite());
}
await stream.CommitAsync();
}
}
public static async Task SaveAsAsync(this WriteableBitmap image, Guid format, IStorageFile file)
{
// bytes...
var bytes = await image.GetPixelBytesAsync();
// save...
using (var stream = await file.OpenTransactedWriteAsync())
{
// encoder...
var encoder = await BitmapEncoder.CreateAsync(format, stream.Stream);
encoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Straight, (uint)image.PixelWidth, (uint)image.PixelHeight,
96, 96, bytes);
await encoder.FlushAsync();
}
}
public static async Task SaveAsAsync(this WriteableBitmap image, Guid format, IStorageFile file)
{
// bytes...
var bytes = await image.GetPixelBytesAsync();
// save...
using (var stream = await file.OpenTransactedWriteAsync())
{
// encoder...
var encoder = await BitmapEncoder.CreateAsync(format, stream.Stream);
encoder.SetPixelData(BitmapPixelFormat.Rgba8, BitmapAlphaMode.Straight, (uint)image.PixelWidth, (uint)image.PixelHeight,
96, 96, bytes);
await encoder.FlushAsync();
}
}
//Stream的写入操作
//文件的Stream其实就是文件内的信息，所以再用Stream来写入文件的数据时，直接保存Stream的信息就可以，并不需要再调用文件的对象进行保存
public async void StreamWrite(IStorageFile file, string content)
{
int size = Int32.MaxValue;
using (StorageStreamTransaction transaction = await file.OpenTransactedWriteAsync())
{
using (DataWriter dataWriter = new DataWriter(transaction.Stream))
{
//文件相关的信息，可以根据文件的规则来进行写入
dataWriter.WriteInt32(size);
dataWriter.WriteString(content);
transaction.Stream.Size = await dataWriter.StoreAsync();
//保存Stream数据
await transaction.CommitAsync();
}
}
}
