加载，显示，在Windows Phone的8.1转换图像从字节数组（数据库） [英] Load, show, convert image from byte array (database) in Windows Phone 8.1

问题描述

完整的问题是如何显示的Windows Phone 8.1，从数据库中加载图像。
图像数据加载为字节数组。（选中 - 加载罚款）

通过指定urisource工作正常显示图像。

 图片IMG =新的图像（）;
img.Source =新的BitmapImage（）{UriSource =新的URI（http://www.domain.com/1.jpg）};
rootgrid.Children.Add（IMG）;
 

但是，当字节阵列（图像的）转化为的BitmapImage - 显示什么。
唯一例外的自由例如我心中已经发现迄今：

 公开的BitmapImage ConvertToBitmapImage（字节[]图片）
{
    InMemoryRandomAccessStream RAS =新InMemoryRandomAccessStream（）;
    VAR的BitmapImage =新的BitmapImage（）;
    VAR的MemoryStream =新的MemoryStream（图片）;
    memoryStream.CopyToAsync（ras.AsStreamForWrite（））;
    bitmapImage.SetSourceAsync（RAS）;
    返回BitmapImage的;
}图片IMG =新的图像（）;
img.Source = ConvertToBitmapImage（picturebytearray）;
rootgrid.Children.Add（IMG）;
 

但是，没有图所示即可。

微软的文档包含例如只流由从内部存储打开文件获得的图像加载。但我需要加载图像，保存在SQLite数据库。
图像数据为JPEG格式。

编辑：
根据工作code freshbm 解决方案：

 公共异步任务＆LT;＆的BitmapImage GT; ConvertToBitmapImage（字节[]图片）
{
    的BitmapImage BitmapImage的= NULL;
    使用（InMemoryRandomAccessStream毫秒​​=新InMemoryRandomAccessStream（））
    {
        使用（DataWriter作家=新DataWriter（ms.GetOutputStreamAt（0）））
        {
            writer.WriteBytes（（字节[]）图像）;
            等待writer.StoreAsync（）;
        }
        BitmapImage的=新的BitmapImage（）;
        bitmapimage.SetSource（毫秒）;
    }
    返回BitmapImage的;
}
 

然后在构造函数中你可以使用：

  img.Source = ConvertToBitmapImage（imagebytearray）。结果;
 

否则

  img.Source =等待ConvertToBitmapImage（imagebytearray）;
 

解决方案

您可以尝试这样的事情来转换字节[]以BitmapImage的：

 使用（InMemoryRandomAccessStream毫秒​​=新InMemoryRandomAccessStream（））
{
    使用（DataWriter作家=新DataWriter（ms.GetOutputStreamAt（0）））
    {
       writer.WriteBytes（（字节[]）fileBytes）;
       writer.StoreAsync（）GetResults（）。
    }
    VAR图像=新的BitmapImage（）;
    image.SetSource（毫秒）;
}
 

发现它这样的：
<一href=\"http://www.$c$cproject.com/Tips/804423/Conversion-between-File-Byte-Stream-BitmapImage-an\">http://www.$c$cproject.com/Tips/804423/Conversion-between-File-Byte-Stream-BitmapImage-an

我用它来读取SQLite数据库的byte []，并将其绑定到图像上的页面。

有关您的code尝试添加等待的异步功能：

 公共异步任务＆LT;＆的BitmapImage GT; ConvertToBitmapImage（字节[]图片）
{
    InMemoryRandomAccessStream RAS =新InMemoryRandomAccessStream（）;
    VAR的BitmapImage =新的BitmapImage（）;
    VAR的MemoryStream =新的MemoryStream（图片）;
    等待memoryStream.CopyToAsync（ras.AsStreamForWrite（））;
    等待bitmapImage.SetSourceAsync（RAS）;
    返回BitmapImage的;
}图片IMG =新的图像（）;
img.Source =等待ConvertToBitmapImage（picturebytearray）;
rootgrid.Children.Add（IMG）;
 

我不擅长异步编程，但我认为这是可行的。

The full question is how to show image loaded from database in windows phone 8.1. Image data is loaded as byte array (checked - loads fine).

Displaying image by specifying urisource works fine.

Image img = new Image();
img.Source = new BitmapImage() {UriSource = new Uri("http://www.domain.com/1.jpg") };
rootgrid.Children.Add(img);    

But when byte array (of image) is converted to BitmapImage - nothing is shown. The only exception free example I'v found so far is:

public BitmapImage ConvertToBitmapImage(byte[] image)
{
    InMemoryRandomAccessStream ras = new InMemoryRandomAccessStream();
    var bitmapImage = new BitmapImage();
    var memoryStream = new MemoryStream(image);
    memoryStream.CopyToAsync(ras.AsStreamForWrite());
    bitmapImage.SetSourceAsync(ras);
    return bitmapImage;
}

Image img = new Image();
img.Source = ConvertToBitmapImage(picturebytearray);
rootgrid.Children.Add(img);

But no picture is shown then.

Microsoft's documentation contains example only of image loading from stream that is obtained by opening file from internal storage. But I need to load image, that is saved in sqlite database. Image data is in jpeg format.

Edit: Working code based on freshbm solution:

public async Task<BitmapImage> ConvertToBitmapImage(byte[] image)
{
    BitmapImage bitmapimage = null;
    using (InMemoryRandomAccessStream ms = new InMemoryRandomAccessStream())
    {
        using (DataWriter writer = new DataWriter(ms.GetOutputStreamAt(0)))
        {
            writer.WriteBytes((byte[])image);
            await writer.StoreAsync();
        }
        bitmapimage = new BitmapImage();
        bitmapimage.SetSource(ms);
    }
    return bitmapimage;
}

Then in constructors you can use:

img.Source = ConvertToBitmapImage(imagebytearray).Result;

or else

img.Source = await ConvertToBitmapImage(imagebytearray);

解决方案

You can try something like this to convert byte[] to BitmapImage:

using (InMemoryRandomAccessStream ms = new InMemoryRandomAccessStream())
{              
    using (DataWriter writer = new DataWriter(ms.GetOutputStreamAt(0)))
    {
       writer.WriteBytes((byte[])fileBytes);
       writer.StoreAsync().GetResults();
    }
    var image = new BitmapImage();
    image.SetSource(ms);
}

Found it on this: http://www.codeproject.com/Tips/804423/Conversion-between-File-Byte-Stream-BitmapImage-an

I'm using it to read byte[] from sqlite database and bind it to Image on Page.

For your code try adding await for Async functions:

public async Task<BitmapImage> ConvertToBitmapImage(byte[] image)
{
    InMemoryRandomAccessStream ras = new InMemoryRandomAccessStream();
    var bitmapImage = new BitmapImage();
    var memoryStream = new MemoryStream(image);
    await memoryStream.CopyToAsync(ras.AsStreamForWrite());
    await bitmapImage.SetSourceAsync(ras);
    return bitmapImage;
}

Image img = new Image();
img.Source = await ConvertToBitmapImage(picturebytearray);
rootgrid.Children.Add(img);

I'm not good at Async programming but I think that this would work.

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