将位图图像转换为byte []数组以存储在sqlite数据库中 [英] Convert a bitmapimage to byte[] array for storage in sqlite database

问题描述

我已经使用filepicker从本地文件夹中选择一张照片，并将该图像分配给xaml页面中的图像控件.现在图像已经存在，我想将其保存到我的sqlite数据库中的byte []字段中.我已经尝试了多种搜索互联网的方法，但是大多数方法都涉及Windows 8.1 Windows Store应用程序中不可用的命名空间(例如System.Drawing).你能建议一种方法吗?这是我用来将byte []数组转换为位图图像的方法.我只想要相反的意思:

I have used filepicker to choose a photo from a local folder and have assigned that image to an image control in xaml page. Now that the image is there, I want to save it to a byte[] field in my sqlite database. I have tried numerous approaches from searching the internet but most involve a namespace that is not available (like System.Drawing) in windows 8.1 windows store app. Can you suggest a method? Here is the method I use to convert from byte[] array to a bitmap image. I just want the reverse of this:

   //this converts VehPhoto Byte[] array to BitMapImage file
    private async Task LoadImageAsync()
    {
        using (InMemoryRandomAccessStream ms = new InMemoryRandomAccessStream())
        {
            // Writes the image byte array in an InMemoryRandomAccessStream
            // that is needed to set the source of VehicleBitMap.
            using (DataWriter writer = new DataWriter(ms.GetOutputStreamAt(0)))
            {
                writer.WriteBytes(vehphoto);
                await writer.StoreAsync();
            }

            var image = new BitmapImage();
            await image.SetSourceAsync(ms);
            vehiclebitmap = image;
        }
    }

感谢您的帮助！

推荐答案

我终于迷失了自己的问题的答案.从我身上浮现出来的是，一旦我从文件中加载照片图像，就可以将其放入字节数组中.因此，在我使用文件选择器选择了一张照片之后，将其转换为可在图像控件中使用的BitMapImage之后，便使用此代码将其分配给我的数据库元素:

I finally stumbled on the answer to my own question. It dawned on me that I could put the photo image into a byte array as soon as I load it from a file. So, right after I select a photo using filepicker, after converting it to a BitMapImage for use in the image control, I use this code to assign it to my database element:

            byte[] fileBytes = null;
            using (IRandomAccessStreamWithContentType stream = await file.OpenReadAsync())
            {
                fileBytes = new byte[stream.Size];
                using (DataReader reader = new DataReader(stream))
                {
                    await reader.LoadAsync((uint)stream.Size);
                    reader.ReadBytes(fileBytes);
                    Vehicle.VehPhoto = fileBytes;
                }
            }

然后，无需将BitmapImage转换为byte []，只需将文件转换为byte [].是的！！！

Then there is no need to convert a BitmapImage to a byte[], just a file to byte[]. Yea!!!!

这篇关于将位图图像转换为byte []数组以存储在sqlite数据库中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！