Answers

• LandLu Member, Xamarin Team Xamurai

  September 2019

  What is the control you are using named imageSlider?
  But if you are meaning you want to consume an Image control in Xamarin and you want to display an image using bytes you could try:

  HttpClient client = new HttpClient();
  var response = await client.GetAsync("https://sample-videos.com/img/Sample-jpg-image-50kb.jpg");
  var bytes = await response.Content.ReadAsByteArrayAsync();
  
  var stream = new MemoryStream(bytes);
  MyImage.Source = ImageSource.FromStream(() => stream);  
  

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• sandy3080 Member ✭✭

  September 2019

  I want to code Xamarin Form

  ImageSlide imageslider is my class,,
  this is my form

  image
  Order no
  IsActive

  Submit Button

  now i upload image
  take order no =1
  IsActive true=true
  but no idea how to convert image to byte[]
  When clicked submit button

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• LandLu Member, Xamarin Team Xamurai

  September 2019

  @sandy3080 If you could detect which image is selected you could record its source.
  Let's assume you load images from the internet then you could get image path.
  Upload the image path or convert it to bytes as you want.

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• sandy3080 Member ✭✭

  September 2019

  plz tell me code @LandLu

  public static byte[] ToByteArray(Image imageIn)
  {
  var ms = new MemoryStream();
  imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
  return ms.ToArray();
  }

  now i using this code but get error

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• LandLu Member, Xamarin Team Xamurai

  September 2019

  @sandy3080 You can't convert the image control to stream directly. Once the stream has been passed to the StreamImageSource it will be released.
  What I mean above is you need to store the resource's path where you got the bytes.
  i.e. I obtained the bytes from the address https://sample-videos.com/img/Sample-jpg-image-50kb.jpg so I needed to store this address in a list corresponding to your images.
  If you have five images to be displayed you need to create a list which contains five image paths.
  When one of the images has been seleceted you could retrieve the image path from the list due to the image's index.
  At last, get the bytes from the image path, upload it to your server.

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• lillian Member ✭✭

  September 2019

  Please have a try, hope it can help you.

  private byte[] ToByteArray(Image image, ImageFormat format)
  {
  using (var ms = new MemoryStream())
  {
  image.Save(ms, format);
  var byData = new byte[ms.Length];
  ms.Position = 0;
  ms.Read(byData, 0, byData.Length);
  ms.Close();
  return byData;
  }
  }

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• rozman50 Member ✭✭

  September 2019

  @sandy3080

  See if this helps you: https://forums.xamarin.com/discussion/comment/387729#Comment_387729

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• sandy3080 Member ✭✭

  September 2019

  @lillian your code is okk but
  image.save() method
  not found in Xamrin forms
  got error

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• LandLu Member, Xamarin Team Xamurai

  September 2019

  @sandy3080 This is not a .Net Standard api: https://docs.microsoft.com/en-us/dotnet/api/system.drawing.image.save?redirectedfrom=MSDN&view=netframework-4.8#System_Drawing_Image_Save_System_String_System_Drawing_Imaging_ImageCodecInfo_System_Drawing_Imaging_EncoderParameters_
  Image here in Xamarin.Forms is a standard control and you can't convert it directly to a byte array.
  You could try my approach to get the image path and convert it to what you need.

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• lillian Member ✭✭

  September 2019

  maybe you can use FFImageLoading

  Here is an example:
  <ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:ffimageloading="clr-namespace:FFImageLoading.Forms;assembly=FFImageLoading.Forms" x:Class="App1.MainPage"> <StackLayout> <ffimageloading:CachedImage x:Name="TestImage" Source="icon" /> <Button Text="Convert" Clicked="Button_OnClicked" /> </StackLayout> </ContentPage>

  private async void Button_OnClicked(object sender, EventArgs e)
  {
  var imageBytes = await TestImage.GetImageAsJpgAsync();
  }

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