将 Image.Source 绑定到 WPF 中的字符串? [英] Binding Image.Source to String in WPF?

问题描述

我有以下 XAML 代码:

I have below XAML code :

<Window x:Class="WpfApplication1.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    DataContext="{Binding RelativeSource={RelativeSource Self}}"
    WindowStartupLocation="CenterScreen"
    Title="Window1" Height="300" Width="300">

    <Grid>
        <Image x:Name="TestImage" Source="{Binding Path=ImageSource}" />
    </Grid>

</Window>

此外，还有一种方法可以从 Base64 字符串生成图像:

Also, there is a method that makes an Image from a Base64 string :

Image Base64StringToImage(string base64ImageString)
{
    try
    {
        byte[] b;
        b = Convert.FromBase64String(base64ImageString);
        MemoryStream ms = new System.IO.MemoryStream(b);
        System.Drawing.Image img = System.Drawing.Image.FromStream(ms);

        //////////////////////////////////////////////
        //convert System.Drawing.Image to WPF image
        System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(img);
        IntPtr hBitmap = bmp.GetHbitmap();
        System.Windows.Media.ImageSource imageSource = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(hBitmap, IntPtr.Zero, Int32Rect.Empty, BitmapSizeOptions.FromEmptyOptions());

        Image wpfImage = new Image();
        wpfImage.Source = imageSource;
        wpfImage.Width = wpfImage.Height = 16;
        //////////////////////////////////////////////

        return wpfImage;
    }
    catch
    {
        Image img1 = new Image();
        img1.Source = new BitmapImage(new Uri(@"/passwordManager;component/images/TreeView/empty-bookmark.png", UriKind.Relative));
        img1.Width = img1.Height = 16;
        return img1;
    }
} 

现在，我要将 TestImage 绑定到 Base64StringToImage 方法的输出.
我使用了以下方式:

Now, I'm gonna bind TestImage to the output of Base64StringToImage method.
I've used the following way :

public string ImageSource { get; set; }
ImageSource = Base64StringToImage("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").Source.ToString(); 

但什么也没发生.
我该如何解决?

but nothing happen.
How can I fix it ?

顺便说一句，我很确定 base64 字符串是正确的

BTW, I'm dead sure that the base64 string is correct

推荐答案

作为对@itowlson 出色答案的补充，您的代码应该如下所示:

As a complement to @itowlson's excellent answer, this is what your code should look like:

// MainWindow.xaml
<Window x:Class="MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <DockPanel>
        <Image Source="{Binding ImageSource}" />
    </DockPanel>
</Window>

// MainWindow.xaml.cs
using System.ComponentModel;
using System.IO;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Imaging;

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();

        var model = new MainModel();
        DataContext = model;

        model.SetImageData(File.ReadAllBytes(@"C:UsersPublicPicturesSample PicturesDesert.jpg"));
    }
}

class MainModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    public void SetImageData(byte[] data) {
        var source = new BitmapImage();
        source.BeginInit();
        source.StreamSource = new MemoryStream(data);
        source.EndInit();

        // use public setter
        ImageSource = source;
    }

    ImageSource imageSource;
    public ImageSource ImageSource
    {
        get { return imageSource; }
        set
        {
            imageSource = value;
            OnPropertyChanged("ImageSource");
        }
    }

    protected void OnPropertyChanged(string name)
    {
        var handler = PropertyChanged;
        if (null != handler)
        {
            handler(this, new PropertyChangedEventArgs(name));
        }
    }
}

这篇关于将 Image.Source 绑定到 WPF 中的字符串?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！