的Xaml

Question

我需要以编程方式生成图像，因此在xaml中使用标记不是一种选择。当窗口加载时，我也试着运行，但是

运行程序只是给我一个空白屏幕：

我的.CS

namespace WpfApplication2
{
    public partial class MainWindow : Window
    {
        public Image anImage;

        public MainWindow()
        {
            InitializeComponent();

            anImage = new Image();
            anImage.Visibility = Visibility.Visible;
            anImage.Width = 120;
            anImage.Height = 310;
            anImage.HorizontalAlignment = HorizontalAlignment.Left;
            anImage.VerticalAlignment = VerticalAlignment.Top;
            anImage.Margin = new Thickness(500, 500, 0, 0);
            BitmapImage bmImage = new BitmapImage();
            bmImage.BeginInit();
            bmImage.UriSource = new Uri("balloonB.png", UriKind.Relative);
            bmImage.EndInit();
            anImage.Source = bmImage;
            anImage.Stretch = Stretch.None;

            this.AddVisualChild(anImage);
            this.InvalidateVisual();
        }
    }
}

我的XAML

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="1024" Width="1280" ResizeMode="NoResize"
                 WindowStartupLocation="CenterScreen" WindowState="Maximized">
    <Grid Width="1280" Height="1024">

    </Grid>
</Window>

Answer 1

您的代码至少有两个问题。

首先，您应该确保可以在运行时加载图像文件。最简单的方法是将文件添加到Visual Studio项目中，可能位于名为＆＃34; Images＆＃34;的文件夹中。文件的构建操作必须设置为Resource，但这仍然是图像文件的默认设置。现在，您可以通过Pack URI（或Resource Pack URI更准确地访问代码中的此图像资源文件）。给定文件夹名称＆＃34; Images＆＃34;，该URI将如下所示：

pack://application:,,,/Images/balloonB.png

其次，您不应使用AddVisualChild将Image控件添加到MainWindow。相反，通过在XAML中设置Grid上的x:Name属性，然后在代码隐藏中使用带有该名称的自动生成的成员变量，将其添加到顶级Grid。

<Window ...>
    <Grid x:Name="rootGrid" Width="1280" Height="1024">
    </Grid>
</Window>

将Image控件添加到Grid：

rootGrid.Children.Add(anImage);

将所有内容放在一起并省略不必要的属性设置，您的代码将如下所示：

var anImage = new Image();
anImage.Width = 120;
anImage.Height = 310;
anImage.HorizontalAlignment = HorizontalAlignment.Left;
anImage.VerticalAlignment = VerticalAlignment.Top;
anImage.Margin = new Thickness(500, 500, 0, 0);
anImage.Source = new BitmapImage(new Uri("pack://application:,,,/Images/balloonB.png"));
rootGrid.Children.Add(anImage);

或者，更短一些：

var anImage = new Image
{
    Width = 120,
    Height = 310,
    HorizontalAlignment = HorizontalAlignment.Left,
    VerticalAlignment = VerticalAlignment.Top,
    Margin = new Thickness(500, 500, 0, 0),
    Source = new BitmapImage(new Uri("pack://application:,,,/Images/balloonB.png"))
};
rootGrid.Children.Add(anImage);

Answer 2

我发现很多次，一个完整的包Uri有点多，简化的Uri也可以，如果不是更好，只需确保你的图像构建属性配置为MSBuild资源：

Image anImage = new Image();
anImage.Visibility = Visibility.Visible;
anImage.Width = 120;
anImage.Height = 310;
anImage.HorizontalAlignment = HorizontalAlignment.Left;
anImage.VerticalAlignment = VerticalAlignment.Top;
BitmapImage bmImage = new BitmapImage(new Uri(@"pack://application:,,,/yournameSpace;component/Subfolder/balloonB.png"));
bmImage.BeginInit();
bmImage.EndInit();
anImage.Source = bmImage;
anImage.Stretch = Stretch.None;
gr.Children.Add(anImage);

的Xaml

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="1024" Width="1280" ResizeMode="NoResize"
                 WindowStartupLocation="CenterScreen" WindowState="Maximized">
    <Grid Name="gr" Width="1280" Height="1024">

    </Grid>
</Window>

Answer 3

此行可能存在问题：

anImage.Margin = new Thickness(500, 500, 0, 0);

我将我的网格重命名为gr并尝试了以下代码并且工作正常，我使用ImageBrush绘制图像：

Image anImage = new Image();
anImage.Visibility = Visibility.Visible;
anImage.Width = 120;
anImage.Height = 310;
anImage.HorizontalAlignment = HorizontalAlignment.Left;
anImage.VerticalAlignment = VerticalAlignment.Top;
//anImage.Margin = new Thickness(500, 500, 0, 0);
BitmapImage bmImage = new BitmapImage();
bmImage.BeginInit();
bmImage.UriSource = new Uri("balloonB.png", UriKind.Relative);
bmImage.EndInit();

ImageBrush ib = new ImageBrush(bmImage);
anImage.Source = ib.ImageSource;
gr.Children.Add(anImage);

的Xaml

<Window x:Class="WpfApplication2.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="1024" Width="1280" ResizeMode="NoResize"
                 WindowStartupLocation="CenterScreen" WindowState="Maximized">
    <Grid Name="gr" Width="1280" Height="1024">

    </Grid>
</Window>

为什么我在WPF中看不到以编程方式生成的图像？

3 个答案:

的Xaml

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