WPF 动态更换图片路径

wpf中动态修改图片路径，其实很简单，有个小伙伴有疑问，绑定了source,为什么不能显示图片呢。。。

通过绑定，修改图片路径，动态显示图片，效果如下：

图片支持本地路径和网络路径，下面就来看看如何做吧：

首先，在项目中创建一个images文件夹，将默认图片复制到其中命名为404.jpg

然后：

创建一个窗口，xaml代码如下：

<Window x:Class="WxDemo.ChageImageDemo"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:WxDemo"mc:Ignorable="d"Background="LightBlue"Title="动态修改图片路径" Height="450" Width="800"><Window.Resources><local:StringToBitmapImageConverter x:Key="imageConverter"/></Window.Resources><Grid><Grid.RowDefinitions><RowDefinition Height="*"/><RowDefinition Height="40"/></Grid.RowDefinitions><Image Source="{Binding ImagePath,Converter={StaticResource imageConverter}}" Grid.Row="0"/><DockPanel Grid.Row="1"><TextBlock Text="输入图片路径：" DockPanel.Dock="Left" VerticalAlignment="Center" FontSize="18"/><TextBox Text="{Binding ImagePath,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"BorderThickness="1" BorderBrush="Black" VerticalContentAlignment="Center"FontSize="18"  Background="LightBlue"/></DockPanel></Grid>
</Window>

有一个图片，和一个文本框，绑定了同一个string类型的ImagePath属性，Source使用了一个转换器。

窗体后台代码如下：

using System;
using System.ComponentModel;
using System.Globalization;
using System.Windows;
using System.Windows.Data;
using System.Windows.Media.Imaging;namespace WxDemo
{public partial class ChageImageDemo : Window, INotifyPropertyChanged{public ChageImageDemo()
{InitializeComponent();DataContext = this;}public event PropertyChangedEventHandler PropertyChanged;public void OnPropertyChanged(string name)
{PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));}private string _imagePath= @"D:\bizhi\清纯\10-1.jpg";public string ImagePath{get { return _imagePath; }set{_imagePath = value;OnPropertyChanged(nameof(ImagePath));}}}public class StringToBitmapImageConverter : System.Windows.Markup.MarkupExtension, IValueConverter{public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{string path = value?.ToString();if(string.IsNullOrEmpty(path)) return new BitmapImage(new Uri("/images/404.jpg",UriKind.Relative));try{return new BitmapImage(new Uri(path));}catch (Exception){return new BitmapImage(new Uri("/images/404.jpg",UriKind.Relative));}}public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{throw new NotImplementedException();}public override object ProvideValue(IServiceProvider serviceProvider)
{return new StringToBitmapImageConverter();}}
}

后台代码里面指定了DataContext,实现了INotifyPropertyChanged接口，并且定义了转换器。

这样就已经实现我们想要的效果啦：