将 base64 绑定到 ffimageloading:CachedImage 时出现问题

Question

I have a problem with creating stacklayout, which contains image created from base64string, downloaded from database. Example of image declare:

In ViewModel: public string ImageString {get; set;} = "[base64string - 95503 chars]"; public string ImageString {get; set;} = "[base64string - 95503 chars]";

Fragment code in xaml: <ffimageloading:CachedImage Aspect="AspectFill" Source="{Binding ImageString}"/>

When I tried base64 directly (instead of binding), it worked. I think the problem is too large binding string.

Any idea of resolving this problem?

Answer 1

If you want to use binding, you can try to convert the ImageBase64String into Xamarin.Forms.ImageSource .

I did a test on my side, and it works on my side. Please refer to the following code:

public class MyViewModle 
    {
        public string ImageBase64 { get; set; }

        public Xamarin.Forms.ImageSource Image { get; set; }


        public MyViewModle() {
            
          ImageBase64 = "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";

            if (ImageBase64 != null)
            {
                if (ImageBase64.Trim() != "")
                {
                    var byteArray = Convert.FromBase64String(ImageBase64);

                    if (byteArray != null)
                    {
                        Image = Xamarin.Forms.ImageSource.FromStream(
                            () => new MemoryStream(Convert.FromBase64String(ImageBase64)));
                    }
                }
            }
        }

    }

Usage example:

<ffimageloading:CachedImage HorizontalOptions="Center" Source="{Binding Image}" DownsampleToViewSize="true" WidthRequest="40"/>

Note:

Do not forget to set the BindingContext for your page.

public partial class MainPage : ContentPage 
    {
        public MainPage()
        {
            InitializeComponent();

            this.BindingContext = new MyViewModle();
        }
    }