Win8 文件相關操作

1.文件選擇

var openPicker = new FileOpenPicker
                {
                    ViewMode = PickerViewMode.Thumbnail,
                    SuggestedStartLocation = PickerLocationId.ComputerFolder
                };
                openPicker.FileTypeFilter.Add("*");


                StorageFile file = await openPicker.PickSingleFileAsync();

2.獲取文件大小

  BasicProperties pro = await file.GetBasicPropertiesAsync();
                UInt64 size = pro.Size;

3.convert StorageFile to byte[]

var bytes = await GetBtyeFromFile(file);

// This is the method to convert the StorageFile to a Byte[]
private async Task GetBtyeFromFile(StorageFile storageFile)
{
    var stream = await storageFile.OpenReadAsync();

    using (var dataReader = new DataReader(stream))
    {
        var bytes = new byte[stream.Size];
        await dataReader.LoadAsync((uint)stream.Size);
        dataReader.ReadBytes(bytes);

        return bytes;
    }
}

4.convert the Byte[] to an Image

var stream = new MemoryStream(bytes);
            var randomAccessStream = new MemoryRandomAccessStream(stream);

            var bi = new BitmapImage();
            bi.ImageFailed += (s, o) =>
            {
        // This event is optional and is used to let us know if something went wrong
                var m = "Failure;
            };

            bi.SetSource(randomAccessStream);

5.獲取文件MD5

private async Task<string> GetMd5(StorageFile file)
        {
            HashAlgorithmProvider alg = Windows.Security.Cryptography.Core.HashAlgorithmProvider.OpenAlgorithm(HashAlgorithmNames.Md5);
            var stream = await file.OpenStreamForReadAsync();
            var inputStream = stream.AsInputStream();
            const uint capacity = 100000000;
            var buffer = new Windows.Storage.Streams.Buffer(capacity);
            var hash = alg.CreateHash();


            while (true)
            {
                await inputStream.ReadAsync(buffer, capacity, InputStreamOptions.None);
                if (buffer.Length > 0)
                    hash.Append(buffer);
                else
                    break;
            }


            string hashText = CryptographicBuffer.EncodeToHexString(hash.GetValueAndReset()).ToUpper();


            inputStream.Dispose();
            stream.Dispose();
            return hashText;
        }

6. 生成GUID

1、Guid.NewGuid().ToString("N") 結果爲：
      38bddf48f43c48588e0d78761eaa1ce6

2、Guid.NewGuid().ToString("D") 結果爲： 
      57d99d89-caab-482a-a0e9-a0a803eed3ba

3、Guid.NewGuid().ToString("B") 結果爲：
     {09f140d5-af72-44ba-a763-c861304b46f8}

4、Guid.NewGuid().ToString("P") 結果爲：
     (778406c2-efff-4262-ab03-70a77d09c2b5)

默認第2種效果