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C# WPF后台动态加控件

zls366 人气:0

概述

在Winform中从后台添加控件相对比较容易,但是在WPF中,我们知道界面是通过XAML编写的,如何把后台写好的控件动态添加到前台呢?本节举例介绍这个问题。

这里要用到UniformGrid布局,UniformGrid 是一种横向的网格分割、纵向的网格分割分别是均等的分割的布局类型.

​项目介绍

-. 这里界面添加一个ComboBox用来下拉选择图片数量;

-. 添加一个button用来执行图片显示;

dispaly下方是图片显示区域

代码设计

-.前台XAML代码:

<Grid>
        <dxlc:LayoutControl Orientation="Vertical">
            <dxlc:LayoutGroup Orientation="Horizontal" View="GroupBox">
                <dxlc:LayoutGroup.Header>
                    <dxlc:LayoutItem Label="Action" Background="#FF004486" Foreground="White"/>
                </dxlc:LayoutGroup.Header>
                <dxlc:LayoutItem Label="Image Count" >
                    <ComboBox SelectedIndex="{Binding ComSelectedIndex}">
                        <ComboBoxItem>2</ComboBoxItem>
                        <ComboBoxItem>4</ComboBoxItem>
                        <ComboBoxItem>6</ComboBoxItem>
                    </ComboBox>
                </dxlc:LayoutItem>
                <dxlc:LayoutItem Width="110">
                    <dx:SimpleButton Content="Image Dispaly" Background="LightGray"
                       cal:Message.Attach="[Event Click]=[btnAdd_Click($source,$eventArgs)]" />
                </dxlc:LayoutItem>
            </dxlc:LayoutGroup>
 
            <dxlc:LayoutGroup Orientation="Horizontal" View="GroupBox">
                <dxlc:LayoutGroup.Header>
                    <dxlc:LayoutItem Label="Dispaly" Background="#FF004486" Foreground="White"/>
                </dxlc:LayoutGroup.Header>
                <UniformGrid
                        cal:Message.Attach="[Event Loaded]=[UniformGrid_Loaded($source,$eventArgs)]" />
            </dxlc:LayoutGroup>
        </dxlc:LayoutControl>
    </Grid>

前台代码比较简单,只要关注下UniformGrid控件,绑定了Loaded事件。

-.后台代码:

[AddINotifyPropertyChangedInterface]
   public class UniformGridViewModel : Screen, IViewModel
   {
       public int ComSelectedIndex { get; set; }
 
       public UniformGrid UniformGrid;
 
       public string[] ImageFullPath;
       public void btnAdd_Click(object sender, RoutedEventArgs e)
       {
           UniformGrid.Children.Clear();
           UniformGrid.Columns = 2;
 
           var count = 0;
           switch(ComSelectedIndex)
           {
               case 0:
                   count = 2;break;
               case 1:
                   count = 4; break;
               case 2:
                   count = 6; break;
               default: break;
           }
           for (int i = 0; i < count; i++)
           {
               Image image = new Image();
               image.Source = LoadImageFreeze(ImageFullPath[i]);
               image.MouseLeftButtonUp += ImageClick;
               image.Name = Path.GetFileNameWithoutExtension(ImageFullPath[i]);
               image.Margin = new Thickness(5);
               UniformGrid.Children.Add(image);
           }
       }
 
       public void ImageClick(object sender, MouseButtonEventArgs e)
       {
           var name = (sender as Image).Name;
           MessageBox.Show($"当前选择的图片名称:{name}");
       }
       public void UniformGrid_Loaded(object sender, RoutedEventArgs e)
       {
           UniformGrid = (UniformGrid)sender;
       }
       public UniformGridViewModel()
       {
           DisplayName = "UniformGrid";
           string imagePath =Path.Combine( AppDomain.CurrentDomain.BaseDirectory, "Images");
           ImageFullPath = Directory.GetFiles(imagePath, "*.png");
       }
 
       public static BitmapImage LoadImageFreeze(string imagePath)
       {
           try
           {
               var bitmap = new BitmapImage();
               if (File.Exists(imagePath))
               {
                   bitmap.BeginInit();
                   bitmap.CacheOption = BitmapCacheOption.OnLoad;
 
                   using (Stream ms = new MemoryStream(File.ReadAllBytes(imagePath)))
                   {
                       bitmap.StreamSource = ms;
                       bitmap.EndInit();
                       bitmap.Freeze();
                   }
               }
               return bitmap;
           }
           catch (Exception)
           {
               return null;
           }
       }
   }

介绍:

①LoadImageFreeze:从路径下加载图片并转换为BitmapImage;

②UniformGrid_Loaded;获取UniformGrid对象;

③ImageFullPath:从项目bin下获取图片文件并读取到这个数组;

④btnAdd_Click:界面button点击事件,这里是核心的代码,主要就是申城图片,然后设定好 UniformGrid的行列以及其他属性后添加到控件里面, UniformGrid.Children.Add(image);

⑤ImageClick:点击后显示图片的名称.

源码

点击这里下载

总结

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