WPF密码可见性切换时VisibilityOff.png图像无法正常显示

可能原因及解决步骤 #

1. 路径与文件名校验

• 严格匹配文件名大小写：WPF的pack URI对大小写敏感，确保代码中的VisibilityOff.png和实际文件名完全一致（包括大小写）。
• 确认目录结构：检查项目中img文件夹是否存在，且VisibilityOff.png确实放在该目录下，无嵌套错误。

2. 修正BitmapImage加载逻辑

后台直接创建BitmapImage时，未设置缓存选项可能导致加载失败，修改为：

PasswordEyeIcon.Source = new BitmapImage(new Uri("pack://application:,,,/img/VisibilityOff.png", UriKind.Absolute)) 
{ 
    CacheOption = BitmapCacheOption.OnLoad 
};

更稳妥的方式是提前在XAML资源字典中定义图像，后台直接引用：
XAML添加资源：

<Window.Resources>
    <BitmapImage x:Key="VisibilityIcon" UriSource="pack://application:,,,/img/Visibility.png"/>
    <BitmapImage x:Key="VisibilityOffIcon" UriSource="pack://application:,,,/img/VisibilityOff.png"/>
</Window.Resources>

后台代码修改：

PasswordEyeIcon.Source = (BitmapImage)FindResource("VisibilityOffIcon");

3. 检查图像文件完整性

• 用图片查看器打开VisibilityOff.png，确认文件未损坏；若损坏，替换为正常图像文件。
• 确认图像格式为WPF支持的类型（如PNG、JPG），无特殊编码问题。

4. 确认资源属性设置

右键VisibilityOff.png → 属性：

• 生成操作设置为Resource
• 复制到输出目录设置为不复制（资源已嵌入程序集，无需复制到输出目录）

优化后完整代码示例 #

XAML部分：

<Window.Resources>
    <BitmapImage x:Key="VisibilityIcon" UriSource="/img/Visibility.png"/>
    <BitmapImage x:Key="VisibilityOffIcon" UriSource="/img/VisibilityOff.png"/>
</Window.Resources>

<Image x:Name="PasswordEyeIcon"
       Source="{StaticResource VisibilityIcon}"
       Width="20" Height="20" Margin="0,0,10,0"
       VerticalAlignment="Center" HorizontalAlignment="Right"
       Cursor="Hand" MouseDown="PasswordEyeIcon_MouseDown"/>

后台代码：

private bool isPasswordVisible = false;

private void PasswordEyeIcon_MouseDown(object sender, MouseButtonEventArgs e)
{
    if (isPasswordVisible)
    {
        PasswordTextBox.Visibility = Visibility.Collapsed;
        PasswordBox.Visibility = Visibility.Visible;
        PasswordBox.Password = PasswordTextBox.Text;
        PasswordEyeIcon.Source = (BitmapImage)FindResource("VisibilityIcon");
        isPasswordVisible = false;
    }
    else
    {
        PasswordTextBox.Text = PasswordBox.Password;
        PasswordBox.Visibility = Visibility.Collapsed;
        PasswordTextBox.Visibility = Visibility.Visible;
        PasswordEyeIcon.Source = (BitmapImage)FindResource("VisibilityOffIcon");
        isPasswordVisible = true;
    }
}

内容的提问来源于stack exchange，提问作者Alex