The basic roadmap is to download web image at first ,
second convert it into memeorystream,
third assign the memorystream to bitmapimage as StreamSource.
//xaml <Window x:Class="WpfApp2.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:local="clr-namespace:WpfApp2" WindowState="Maximized" mc:Ignorable="d" Title="MainWindow" Height="450" Width="800"> <Grid> <Image x:Name="img"/> </Grid> </Window> //xaml.cs using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Net; using System.Text; using System.Threading.Tasks; using System.Windows; using System.Windows.Controls; using System.Windows.Data; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.Imaging; using System.Windows.Navigation; using System.Windows.Shapes; using static System.Net.Mime.MediaTypeNames; namespace WpfApp2 { /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { static string url = "https://wx4.sinaimg.cn/mw690/007ucPXmgy1hteb8tr7gjj311x1kwhdt.jpg"; public MainWindow() { InitializeComponent(); //LoadWebImageSync(); LoadWebImageAsync(); } private void LoadWebImageSync() { WebClient client = new WebClient(); var imgBytes = client.DownloadData(url); if(imgBytes!=null && imgBytes.Any()) { BitmapImage bmi = new BitmapImage(); bmi.BeginInit(); MemoryStream ms = new MemoryStream(imgBytes); ms.Seek(0, SeekOrigin.Begin); bmi.StreamSource = ms; bmi.EndInit(); img.Source = bmi; } } private void LoadWebImageAsync() { WebClient client = new WebClient(); client.DownloadDataAsync(new Uri(url)); client.DownloadDataCompleted += Client_DownloadDataCompleted; } private void Client_DownloadDataCompleted(object sender, DownloadDataCompletedEventArgs e) { var imgBytes = e.Result; if (imgBytes != null && imgBytes.Any()) { MemoryStream stream = new MemoryStream(imgBytes); BitmapImage bmi = new BitmapImage(); bmi.BeginInit(); bmi.StreamSource = stream; bmi.EndInit(); img.Source = bmi; } } } }
Here I recommand the asynchronous method which will not block other thread.