c# WPF中自定義加載時實現帶動畫效果的Form和FormItem

更新時間：2021年03月05日 11:21:06 作者：Hello 尋夢者！

這篇文章主要介紹了c# WPF中自定義加載時實現帶動畫效果的Form和FormItem，幫助大家更好的理解和學習使用c#，感興趣的朋友可以了解下

背景

　　今天我們來談一下我們自定義的一組WPF控件Form和FormItem,然后看一下如何自定義一組完整地組合WPF控件，在我們很多界面顯示的時候我們需要同時顯示文本、圖片并且我們需要將這些按照特定的順序整齊的排列在一起，這樣的操作當然通過定義Grid和StackPanel然后組合在一起當然也是可以的，我們的這一組控件就是將這個過程組合到一個Form和FormItem中間去，從而達到這樣的效果，我們首先來看看這組控件實現的效果。

一動畫效果

　　看了這個效果之后我們來看看怎么來使用Form和FormItem控件，后面再進一步分析這兩個控件的一些細節(jié)信息。

<xui:TabControl Canvas.Left="356" Canvas.Top="220">
                   <xui:TabItem Header="Overview">
                       <xui:Form Margin="2" >
                           <xui:FormItem Content="Test1" Height="30"></xui:FormItem>
                           <xui:FormItem Content="Test2" Height="30"></xui:FormItem>
                           <xui:FormItem Content="Test3" Height="30"></xui:FormItem>
                       </xui:Form>
                   </xui:TabItem>
                   <xui:TabItem Header="Plumbing">
                       <xui:Form Margin="2" Columns="2" Rows="2">
                           <xui:FormItem Content="Demo1" Height="30" Margin="5 2"></xui:FormItem>
                           <xui:FormItem Content="Demo2" Height="30" Margin="5 2"></xui:FormItem>
                           <xui:FormItem Content="Demo3" Height="30" Margin="5 2"></xui:FormItem>
                           <xui:FormItem Content="Demo4" Height="30" Margin="5 2"></xui:FormItem>
                       </xui:Form>
                   </xui:TabItem>
                   <xui:TabItem Header="Clean">
                       <xui:TextBox Text="Test2" Width="220" Height=" 30" Margin="5"></xui:TextBox>
                   </xui:TabItem>
               </xui:TabControl>

　　這個里面xui命名控件是我們的自定義控件庫的命名空間，這個里面的TableControl也是一種特殊的自定義的TableControl，關于這個TableControl我們后面也會進一步分析。

二自定義控件實現

　　按照上面的順序我們先來分析Form控件，然后再分析FormItem控件的實現細節(jié)

　　2.1 Form

　　通過上面的代碼我們發(fā)現Form是可以承載FormItem的，所以它是一個可以承載子控件的容器控件，這里Form是集成ItemsControl的，我們來看看具體的代碼

public class Form : ItemsControl
    {
        static Form()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(Form), new FrameworkPropertyMetadata(typeof(Form)));
        }
 
        public double HeaderWidth
        {
            get { return (double)GetValue(HeaderWidthProperty); }
            set { SetValue(HeaderWidthProperty, value); }
        }
 
        // Using a DependencyProperty as the backing store for HeaderWidth.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty HeaderWidthProperty =
            DependencyProperty.Register("HeaderWidth", typeof(double), typeof(Form), new PropertyMetadata(70D));
 
        public int Rows
        {
            get { return (int)GetValue(RowsProperty); }
            set { SetValue(RowsProperty, value); }
        }
 
        // Using a DependencyProperty as the backing store for Rows.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty RowsProperty =
            DependencyProperty.Register("Rows", typeof(int), typeof(Form), new PropertyMetadata(0));
 
        public int Columns
        {
            get { return (int)GetValue(ColumnsProperty); }
            set { SetValue(ColumnsProperty, value); }
        }
 
        // Using a DependencyProperty as the backing store for Columns.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty ColumnsProperty =
            DependencyProperty.Register("Columns", typeof(int), typeof(Form), new PropertyMetadata(1));
 
    }

　　然后我們再來看看Form的樣式文件

<Style TargetType="local:Form">
        <Setter Property="Padding" Value="10"></Setter>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="local:Form">
                    <ScrollViewer Background="#eee" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Auto">
                        <UniformGrid Columns="{TemplateBinding Columns}" Rows="{TemplateBinding Rows}" IsItemsHost="True" Background="Transparent" VerticalAlignment="Top" Margin="{TemplateBinding Padding}"></UniformGrid>
                    </ScrollViewer>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
        <Setter Property="ItemTemplate">
            <Setter.Value>
                <DataTemplate>
                    <ContentPresenter Content="{Binding}" Focusable="False"></ContentPresenter>
                </DataTemplate>
            </Setter.Value>
        </Setter>
    </Style>

　　這里我們使用UniformGrid作為內容承載容器，所以我們現在清楚了為什么需要定義Columns和Rows這兩個依賴項屬性了，這個UniformGrid是嵌套在ScrollerViewer中的，所以如果其子控件超出了一定范圍，其子控件外面是會顯示滾動條的。

　　2.2 FormItem

　　FormItem是從ListBoxItem繼承而來，而ListBoxItem又是從ContentControl繼承而來的，所以可以添加到任何具有Content屬性的控件中去，常見的ListBoxItem可以放到ListBox中，也可以放到ItemsControl中去，ListBoxItem可以橫向和TreeViewItem進行比較，只不過TreeViewItem是直接從HeaderedItemsControl繼承過來的，然后再繼承自ItemsControl。兩者有很多的共同之處，可以做更多的橫向比較，我們今天只是來講ListBoxItem，首先看看我們使用的樣式，這里貼出前端代碼：

<Style TargetType="local:FormItem">
        <Setter Property="Margin" Value="0 0 0 15"></Setter>
        <Setter Property="Background" Value="#fff"></Setter>
        <Setter Property="Height" Value="50"></Setter>
        <Setter Property="HorizontalAlignment" Value="Stretch"></Setter>
        <Setter Property="VerticalAlignment" Value="Stretch"></Setter>
        <Setter Property="Padding" Value="6"></Setter>
        <Setter Property="Foreground" Value="{StaticResource DarkColor}"></Setter>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="local:FormItem">
                    <Grid Background="{TemplateBinding Background}" Height="{TemplateBinding Height}">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="{Binding HeaderWidth,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=local:Form}}"></ColumnDefinition>
                            <ColumnDefinition Width="*"></ColumnDefinition>
                        </Grid.ColumnDefinitions>
                        <Rectangle Width="3" HorizontalAlignment="Left" Fill="{StaticResource Highlight}"></Rectangle>
                        <StackPanel VerticalAlignment="Center" HorizontalAlignment="Left" Margin="13 0 0 0" Orientation="Horizontal">
                            <Image x:Name="Icon" Source="{TemplateBinding Icon}" Width="24" Height="24" Margin="0 0 10 0" VerticalAlignment="Center" HorizontalAlignment="Left"></Image>
                            <TextBlock Text="{TemplateBinding Title}" Foreground="{TemplateBinding Foreground}" VerticalAlignment="Center" HorizontalAlignment="Left"></TextBlock>
                        </StackPanel>
                        <ContentPresenter Margin="{TemplateBinding Padding}" Grid.Column="1" HorizontalAlignment="{TemplateBinding HorizontalAlignment}" VerticalAlignment="{TemplateBinding VerticalAlignment}"></ContentPresenter>
                    </Grid>
                    <ControlTemplate.Triggers>
                        <Trigger Property="Icon" Value="{x:Null}">
                            <Setter Property="Visibility" Value="Collapsed" TargetName="Icon"></Setter>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

　　這里我們重寫了ListBoxItem 的ControlTemplate，我們需要注意的一個地方就是我們使用了

<ContentPresenter Margin="{TemplateBinding Padding}" Grid.Column="1" HorizontalAlignment="{TemplateBinding HorizontalAlignment}" VerticalAlignment="{TemplateBinding VerticalAlignment}"></ContentPresenter>

來替代ListBoxItem的Content，我們需要始終記住，只有控件擁有Content屬性才能使用ContentPresenter ，這個屬性是用來呈現控件的Content。

另外一個需要重點介紹的就是FormItem這個類中的代碼，這個控件在加載的時候所有的效果都是在后臺中進行加載的，首先貼出相關的類的實現，然后再做進一步的分析。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;
 
namespace X.UI
{
    public class FormItem : ListBoxItem
    {
        static FormItem()
        {
            DefaultStyleKeyProperty.OverrideMetadata(typeof(FormItem), new FrameworkPropertyMetadata(typeof(FormItem)));          
        }
 
        public FormItem()
        {
            System.Windows.Media.TranslateTransform transform = EnsureRenderTransform<System.Windows.Media.TranslateTransform>(this);
            transform.X = transform.Y = 100;
            Opacity = 0;
 
            IsVisibleChanged += FormItem_IsVisibleChanged;
        }
 
        void FormItem_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            if (this.Parent is Form)
            {
                if (!IsVisible)
                {
                    int index = (this.Parent as Form).Items.IndexOf(this);
                    System.Windows.Media.TranslateTransform transform = EnsureRenderTransform<System.Windows.Media.TranslateTransform>(this);
                    DoubleAnimation da = new DoubleAnimation()
                    {
                        From = 0,
                        To = 100,
                        EasingFunction = new CircleEase { EasingMode = EasingMode.EaseOut }
                    };
                    transform.BeginAnimation(System.Windows.Media.TranslateTransform.XProperty, da);
                    transform.BeginAnimation(System.Windows.Media.TranslateTransform.YProperty, da);
                    DoubleAnimation daopacity = new DoubleAnimation
                    {
                        From = 1,
                        To = 0,
                    };
                    this.BeginAnimation(UIElement.OpacityProperty, daopacity);
                }
                else
                {
                    int index = (this.Parent as Form).Items.IndexOf(this);
                    System.Windows.Media.TranslateTransform transform = EnsureRenderTransform<System.Windows.Media.TranslateTransform>(this);
                    DoubleAnimation da = new DoubleAnimation()
                    {
                        From = 100,
                        To = 0,
                        BeginTime = TimeSpan.FromMilliseconds(100 * (index + 1)),
                        Duration = TimeSpan.FromMilliseconds(666),
                        EasingFunction = new CircleEase { EasingMode = EasingMode.EaseOut }
                    };
                    transform.BeginAnimation(System.Windows.Media.TranslateTransform.XProperty, da);
                    transform.BeginAnimation(System.Windows.Media.TranslateTransform.YProperty, da);
                    DoubleAnimation daopacity = new DoubleAnimation
                    {
                        From = 0,
                        To = 1,
                        BeginTime = TimeSpan.FromMilliseconds(100 * (index + 1)),
                        Duration = TimeSpan.FromMilliseconds(666),
                        EasingFunction = new CircleEase { EasingMode = EasingMode.EaseOut }
                    };
                    this.BeginAnimation(UIElement.OpacityProperty, daopacity);
                }
            }
        }
 
        private T EnsureRenderTransform<T>(UIElement uiTarget)
            where T : Transform
        {
            if (uiTarget.RenderTransform is T)
                return uiTarget.RenderTransform as T;
            else
            {
                T instance = typeof(T).Assembly.CreateInstance(typeof(T).FullName) as T;
                uiTarget.RenderTransform = instance;
                return instance;
            }
        }
 
        public string Title
        {
            get { return (string)GetValue(TitleProperty); }
            set { SetValue(TitleProperty, value); }
        }
 
        // Using a DependencyProperty as the backing store for Title.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty TitleProperty =
            DependencyProperty.Register("Title", typeof(string), typeof(FormItem), new PropertyMetadata(""));
 
 
        public ImageSource Icon
        {
            get { return (ImageSource)GetValue(IconProperty); }
            set { SetValue(IconProperty, value); }
        }
 
        // Using a DependencyProperty as the backing store for Icon.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty IconProperty =
            DependencyProperty.Register("Icon", typeof(ImageSource), typeof(FormItem), new PropertyMetadata(null));
 
    }
}

這里在FormItem的構造函數中，添加了一個IsVisibleChanged事件，這個事件會在加載當前控件的時候發(fā)生，另外當當前控件的屬性值發(fā)生變化的時候會觸發(fā)該效果。其實效果就是同時在X和Y方向做一個平移的效果，這個也是一個常用的效果。

我們重點討論的是下面的這段代碼：

private T EnsureRenderTransform<T>(UIElement uiTarget)
           where T : Transform
       {
           if (uiTarget.RenderTransform is T)
               return uiTarget.RenderTransform as T;
           else
           {
               T instance = typeof(T).Assembly.CreateInstance(typeof(T).FullName) as T;
               uiTarget.RenderTransform = instance;
               return instance;
           }
       }

　　這里我們創(chuàng)建TranslateTransform的時候是使用的System.Windows.Media.TranslateTransform transform = EnsureRenderTransform<System.Windows.Media.TranslateTransform>(this);這個方法，而不是每次都new一個對象，每次new一個對象的效率是很低的，而且會占據內存，我們如果已經創(chuàng)建過當前對象完全可以重復利用，這里我們使用了帶泛型參數的函數來實現當前效果，typeof(T).Assembly.CreateInstance(typeof(T).FullName) as T，核心是通過程序集來創(chuàng)建對象，這種方式我們也是經常會使用的，比如我們可以通過獲取應用程序級別的程序集來通過Activator.CreateInstance來創(chuàng)建窗體等一系列的對象，這種通過反射的機制來擴展的方法是我們需要特別留意的，另外寫代碼的時候必須注重代碼的質量和效率，而不僅僅是實現了某一個功能，這個在以后的開發(fā)過程中再一點點去積累去吸收。

以上就是c# WPF中自定義加載時實現帶動畫效果的Form和FormItem的詳細內容，更多關于c# wpf實現帶動畫效果的Form和FormItem的資料請關注腳本之家其它相關文章！

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