如何Base64编码字符串转换成图像，然后将其绑定到GridView控件中的Metro风格的应用程序

我从网络服务的产品集合，我预览网格视图这个产品，但我得到的产品为Base64字符串的图像。 我怎样才能将其转换为图像，并将其绑定到网格视图的图像？

任何一段代码，这将帮助我在这个问题上。

Answer 1:

在WPF /地铁/ Silverlight中，图像是UI控制。 它的源设置为的BitmapSource。 的BitmapSource是一种数据结构来保存图像数据。

以下是从字节数组检索的BitmapImage的代码。

public BitmapImage ImageFromBuffer(Byte[] bytes)
    {
        MemoryStream stream = new MemoryStream(bytes);
        BitmapImage image = new BitmapImage();
        image.SetSource ( stream.AsRandomAccessStream());
        return image;
    }

需要注意的是stream.AsRandomAccessStream是不是在API可用这是一个扩展方法。 我发现它从响应IDWMaster这个SO问题

下面是扩展方法的代码

 public static class MicrosoftStreamExtensions
    {
        public static IRandomAccessStream AsRandomAccessStream(this Stream stream)
        {
            return new RandomStream(stream);
        }
    }
    class RandomStream : IRandomAccessStream
    {
        Stream internstream;
        public RandomStream(Stream underlyingstream)
        {
            internstream = underlyingstream;
        }
        public IInputStream GetInputStreamAt(ulong position)
        {
            internstream.Position = (long)position;
            return internstream.AsInputStream();
        }

        public IOutputStream GetOutputStreamAt(ulong position)
        {
            internstream.Position = (long)position;
            return internstream.AsOutputStream();
        }

        public ulong Size
        {
            get
            {
                return (ulong)internstream.Length;
            }
            set
            {
                internstream.SetLength((long)value);
            }
        }

        public bool CanRead
        {
            get { return internstream.CanRead; }
        }

        public bool CanWrite
        {
            get { return internstream.CanWrite; }
        }

        public IRandomAccessStream CloneStream()
        {
            //HACK, this is not clone, proper implementation is required, returned object will share same internal stream
            return new RandomStream(this.internstream);
        }

        public ulong Position
        {
            get { return (ulong)internstream.Position; }
        }

        public void Seek(ulong position)
        {
            internstream.Seek((long)position, SeekOrigin.Current);
        }

        public void Dispose()
        {
            internstream.Dispose();
        }

        public Windows.Foundation.IAsyncOperationWithProgress<IBuffer, uint> ReadAsync(IBuffer buffer, uint count, InputStreamOptions options)
        {
            throw new NotImplementedException();
        }

        public Windows.Foundation.IAsyncOperation<bool> FlushAsync()
        {
            throw new NotImplementedException();
        }

        public Windows.Foundation.IAsyncOperationWithProgress<uint, uint> WriteAsync(IBuffer buffer)
        {
            throw new NotImplementedException();
        }
    }

去年3种方法未实现

我没有测试过，但上面的应该主要工作（可能是一些细化后）。

Answer 2:

这似乎为我工作：

    public static BitmapImage Base64StringToBitmap(string source)
    {
        var ims = new InMemoryRandomAccessStream();
        var bytes = Convert.FromBase64String(source);
        var dataWriter = new DataWriter(ims);
        dataWriter.WriteBytes(bytes);
        dataWriter.StoreAsync();
        ims.Seek(0);
        var img = new BitmapImage();
        img.SetSource(ims);
        return img;
    }

注意：我不期待任何东西，img.SetSource应该照顾推迟负荷。

Answer 3:

下面是结合该方法Base64String到Image控制

1. 转换的字符串字节[]如下

    byte[] bytes = System.Convert.FromBase64String(thebase64string); 

2. 通过字节[]，并要结合图像发送到图像控制。

    public async void SetImageFromByteArray(byte[] data, Windows.UI.Xaml.Controls.Image image) { InMemoryRandomAccessStream raStream = new InMemoryRandomAccessStream(); DataWriter writer = new DataWriter(raStream); // Write the bytes to the stream writer.WriteBytes(data); // Store the bytes to the MemoryStream await writer.StoreAsync(); await writer.FlushAsync(); // Detach from the Memory stream so we don't close it writer.DetachStream(); raStream.Seek(0); BitmapImage bitMapImage = new BitmapImage(); bitMapImage.SetSource(raStream); image.Source = bitMapImage; } 

Answer 4:

尝试是这样的：

byte[] encodedDataAsBytes = System.Convert.FromBase64String(encodedData);
MemoryStream stream = new MemoryStream(encodedDataAsBytes.Length);
stream.Write(encodedDataAsBytes, 0, encodedDataAsBytes.Length);
Image img = Image.FromStream(stream);

我还没有和地铁工作过，所以我不能用结合网格帮助..最好的问候。

文章来源: How to convert Base64 string to image, then bind it to GridView in a Metro Style App?