i am trying to convert a bitmap to a base64 string.i can convert to from string to bitmap...but it seems like there is a problem when converting from bitmap to string.I was hoping you guys could give me a hand
public static string BitmapToString(BitmapImage image)
{
Stream stream = image.StreamSource ;
Byte[] buffer = null;
if (stream != null && stream.Length > 0)
{
using (BinaryReader br = new BinaryReader(stream))
{
buffer = br.ReadBytes((Int32)stream.Length);
}
}
return Convert.ToBase64String(buffer);
}
it gets a ArgumentNullException was unhandled Value cannot be null. Parameter name: inArray when returning Convert.ToBase64String(buffer)
Help?
Try this alternative:
public string BitmapToBase64(BitmapImage bi)
{
MemoryStream ms = new MemoryStream();
PngBitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bi));
encoder.Save(ms);
byte[] bitmapdata = ms.ToArray();
return Convert.ToBase64String(bitmapdata);
}
First of all, it is necessary to save BitmapImage
data into memory using some bitmap encoder ( PngBitmapEncoder
for example).
public static byte[] EncodeImage(BitmapImage bitmapImage)
{
using (MemoryStream memoryStream = new MemoryStream())
{
BitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapImage));
encoder.Save(memoryStream);
return memoryStream.ToArray();
}
}
Then just encode the binary data with Base64-encoding.
const string filePath = @"...";
const string outFilePath = @"...";
const string outBase64FilePath = @"...";
// Constuct test BitmapImage instance.
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = File.OpenRead(filePath);
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.EndInit();
// Convert BitmapImage to byte array.
byte[] imageData = EncodeImage(bitmapImage);
File.WriteAllBytes(outFilePath, imageData);
// Encode with Base64.
string base64String = Convert.ToBase64String(imageData);
// Write to file (for example).
File.WriteAllText(outBase64FilePath, base64String);
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