Question

我需要导入多个图像，并在一个图像中操作它们，就像拼贴画一样。我只需要简单的工具，如翻译图像，旋转图像等等。

我在学习mvvm的过程中，大部分视图都已完成。我不知道如何将导入的图像添加到一个画布。我可以使用某种内置的图像类吗？或者我可以从哪个图书馆开始？

现在我可以将图像导入列表了。我的目标是能够将所选图像添加到画布上，并在画布上操作该图像，然后导出/保存图像。

Answer 1

然而你所看到的内容太宽泛而无法回答，但这是一个小样本

XAML

    <Canvas x:Name="canvas" MouseDown="canvas_MouseDown" Background="Transparent"/>

背后的代码

    private void canvas_MouseDown(object sender, MouseButtonEventArgs e)
    {
        Random rand = new Random(DateTime.Now.Millisecond);
        var uriSource = new Uri(@"desert.jpg", UriKind.Relative);
        for (int i = 0; i < 10; i++)
        {
            Image img = new Image();
            img.Width = rand.NextDouble() * 200;
            img.Height = rand.NextDouble() * 200;
            img.Stretch= Stretch.UniformToFill;
            img.Source = new BitmapImage(uriSource);
            img.RenderTransform = new RotateTransform(rand.NextDouble() * 360);
            Canvas.SetLeft(img, (rand.NextDouble() * canvas.ActualWidth));
            Canvas.SetTop(img, (rand.NextDouble() * canvas.ActualHeight));
            canvas.Children.Add(img);
        }
    }

结果

result

上面的

也可以用MVVM方式完成，如果你也期待看到它，请告诉我。

MVVM方法

这是通过MVVM复制上述代码

XAML

<Grid>
    <Grid.Resources>
        <l:ViewModel x:Key="viewModel" />
        <l:ImageLocationConverter x:Key="ImageLocationConverter" />
        <Style TargetType="ContentPresenter">
            <Setter Property="Canvas.Left">
                <Setter.Value>
                    <MultiBinding Converter="{StaticResource ImageLocationConverter}">
                        <Binding Path="Left" />
                        <Binding Path="ActualWidth"
                                 RelativeSource="{RelativeSource FindAncestor,AncestorType=Canvas}" />
                    </MultiBinding>
                </Setter.Value>
            </Setter>
            <Setter Property="Canvas.Top">
                <Setter.Value>
                    <MultiBinding Converter="{StaticResource ImageLocationConverter}">
                        <Binding Path="Top" />
                        <Binding Path="ActualHeight"
                                 RelativeSource="{RelativeSource FindAncestor,AncestorType=Canvas}" />
                    </MultiBinding>
                </Setter.Value>
            </Setter>
        </Style>
    </Grid.Resources>
    <ItemsControl ItemsSource="{Binding Images,Source={StaticResource viewModel}}">
        <ItemsControl.ItemsPanel>
            <ItemsPanelTemplate>
                <Canvas />
            </ItemsPanelTemplate>
        </ItemsControl.ItemsPanel>
        <ItemsControl.ItemTemplate>
            <DataTemplate>
                <Grid>
                    <Border BorderBrush="White"
                            BorderThickness="5">
                        <Image Source="{Binding Image}"
                               Width="{Binding Width}"
                               Height="{Binding Height}"
                               Stretch="UniformToFill">
                        </Image>
                        <Border.RenderTransform>
                            <RotateTransform Angle="{Binding Angle}" />
                        </Border.RenderTransform>
                    </Border>
                    <Grid.Effect>
                        <DropShadowEffect Opacity=".5"
                                          BlurRadius="10" />
                    </Grid.Effect>
                </Grid>
            </DataTemplate>
        </ItemsControl.ItemTemplate>
    </ItemsControl>
</Grid>

我通过向模板添加更多详细信息来增强视图

Viewmodel，model＆amp;转换器类

namespace CSharpWPF
{
    class ViewModel : DependencyObject
    {
        public ViewModel()
        {
            Images = new ObservableCollection<CollageImage>();
            GenerateCollage();
        }
        public ObservableCollection<CollageImage> Images { get; private set; }

        public void GenerateCollage()
        {
            Random rand = new Random(DateTime.Now.Millisecond);
            var uriSource = new Uri(@"desert.jpg", UriKind.Relative);
            for (int i = 0; i < 10; i++)
            {
                CollageImage img = new CollageImage();
                img.Left = (0.2 + rand.NextDouble()) % 0.8;
                img.Top = (0.2 + rand.NextDouble()) % 0.8;
                img.Width = 100 + rand.NextDouble() * 100;
                img.Height = 100 + rand.NextDouble() * 100;
                img.Image = "desert.jpg";
                img.Angle = rand.NextDouble() * 360;
                Images.Add(img);
            }
        }
    }

    class CollageImage
    {
        public string Image { get; set; }
        public double Left { get; set; }
        public double Top { get; set; }
        public double Width { get; set; }
        public double Height { get; set; }
        public double Angle { get; set; }
    }

    class ImageLocationConverter : IMultiValueConverter
    {
        public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            double value = (double)values[0];
            double max = (double)values[1];

            return value * max;
        }

        public object[] ConvertBack(object value, Type[] targetTypes, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}

结果

result

如何在C＃中使用WPF从多个导入的图像中制作图像拼贴？

1 个答案: