Windows Phone 8 - 使用Binding将byte []数组加载到XAML图像中

Question

我将图像存储为byte []数组,因为我无法将它们存储为BitmapImage.ShotItem类将存储在IsolatedStorage中的observableCollection中.

namespace MyProject.Model
{
    public class ShotItem : INotifyPropertyChanged, INotifyPropertyChanging
    {
        private byte[] _shotImageSource;
        public byte[] ShotImageSource
        {
            get
            {
                return _shotImageSource;
            }
            set
            {
                NotifyPropertyChanging("ShotImageSource");

                _shotImageSource = value;
                NotifyPropertyChanged("ShotImageSource");
            }
        }
        ...
    }
}

在我的xaml文件中,我有以下内容:

<Image Source="{Binding ShotImageSource}" Width="210" Height="158" Margin="12,0,235,0" VerticalAlignment="Top" />

不幸的是,我无法将图像作为字节直接加载到xaml中的Image容器中.我不知何故需要将ShotImageSource byte []转换为BitmapImage.我正在加载相当多的图像,所以这也必须异步完成.

我试图使用转换器绑定,但我不知道如何让它工作.任何帮助将不胜感激 :).

Answer 1

下面是一个代码Converter,将您转换byte[]成BitmapImage:

public class BytesToImageConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if (value != null && value is byte[])
        {
            byte[] bytes = value as byte[];
            MemoryStream stream = new MemoryStream(bytes);
            BitmapImage image = new BitmapImage();

            image.SetSource(stream);

            return image;
        }

        return null;

    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}