Convert Object to Byte Array - xamarin.ios

Question

Edit :
Sorry for the late response.
I tried the code in the answer ,but I had a problem with the conversion from Byte to Image .
public override void ViewDidLoad()
{
var image = UIImage.FromFile("image.png");
var imageWidth = image.Size.Width;
var imageHeight = image.Size.Height;
var documents = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
var fullfilename = Path.Combine(documents, "Image.json");
// save json methode
SaveImageJson(image, fullfilename);
// read json methode
var newImage = readImageJson(fullfilename, imageWidth, imageHeight);
}
public static void SaveImageJson(UIImage image, string fullfilename)
{
// Convert image to byteArray
Byte[] imageByteArray = ReadFully(image.AsPNG().AsStream());
// Serialize object
var json = JsonConvert.SerializeObject(imageByteArray, Formatting.Indented);
// Save to file
File.WriteAllText(fullfilename, json);
}
public static byte[] ReadFully(Stream input)
{
byte[] buffer = new byte[16 * 1024];
using (MemoryStream ms = new MemoryStream())
{
int read;
while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
{
ms.Write(buffer, 0, read);
}
return ms.ToArray();
}
}
public static UIImage readImageJson(string fullfilename, nfloat width, nfloat height)
{
var filenameNewImage = File.ReadAllText(fullfilename, System.Text.Encoding.ASCII);
var jsonNewImage = JsonConvert.DeserializeObject(filenameNewImage);
Byte[] ByteNewImage = ObjectToByteArray(jsonNewImage);
UIImage NewImage = new UIImage();
NewImage = ImageFromBytes(ByteNewImage, width, height);
return NewImage;
}
public static byte[] ObjectToByteArray(Object obj)
{
BinaryFormatter bf = new BinaryFormatter();
using (var ms = new MemoryStream())
{
bf.Serialize(ms, obj);
return ms.ToArray();
}
}
private static UIImage ImageFromBytes(byte[] bytes, nfloat width, nfloat height)
{
try
{
NSData data = NSData.FromArray(bytes);
UIImage image = UIImage.LoadFromData(data);
CGSize scaleSize = new CGSize(width, height);
UIGraphics.BeginImageContextWithOptions(scaleSize, false, 0);
image.Draw(new CGRect(0, 0, scaleSize.Width, scaleSize.Height));
UIImage resizedImage = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
return resizedImage;
}
catch (Exception)
{
return null;
}
}
I have a problem converting an Object to a Byte Array
I have a Xamarin.IOS simulation in which I have to read the data which is an image that i saved before using the Json method . I have a problem while reading my data back and I think it has a relation with the conversion . I used a method to convert the object that I get from the Json file to an Byte Array, so I can convert that later to an UIImage , unfortunately the conversion doesn't work because when I compare the Byte Array I saved and the one I got from method read , I found out that they are different
public override void ViewDidLoad()
{
base.ViewDidLoad();
// getting the file that we saved the data before
var documents = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
var filename = Path.Combine(documents, "account.json");
File.WriteAllText(filename, json);
var filename2 = File.ReadAllText(filename,System.Text.Encoding.ASCII);
var json2 = ObjectToByteArray(JsonConvert.DeserializeObject(filename2));
NSData data2 = NSData.FromArray(json2);
UIImage image2 = new UIImage();
image2 = UIImage.LoadFromData(data2);
img.Image = image2;
}
public static byte[] ObjectToByteArray(Object obj)
{
BinaryFormatter bf = new BinaryFormatter();
using (var ms = new MemoryStream())
{
bf.Serialize(ms, obj);
return ms.ToArray();
}
}

Answer 1

Use another conversion.
First of all, convert your UIImage to Stream. To do it use 'myUIImage.AsPng().AsStream()'. Then convert 'Stream' to 'Byte Array'. To do so use:
public static byte[] ReadFully(Stream input)
{
byte[] buffer = new byte[16*1024];
using (MemoryStream ms = new MemoryStream())
{
int read;
while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
{
ms.Write(buffer, 0, read);
}
return ms.ToArray();
}
}
Then you can safely serialize it.
To make Image from Byte Array you can use this extension
private UIImage ImageFromBytes(byte[] bytes, nfloat width, nfloat height)
{
try {
NSData data = NSData.FromArray(bytes);
UIImage image = UIImage.LoadFromData(data);
CGSize scaleSize = new CGSize(width, height);
UIGraphics.BeginImageContextWithOptions(scaleSize, false, 0);
image.Draw(new CGRect(0,0, scaleSize.Width, scaleSize.Height));
UIImage resizedImage = UIGraphics.GetImageFromCurrentImageContext();
UIGraphics.EndImageContext();
return resizedImage;
} catch (Exception) {
return null;
}
}
Believe this will be helpful.