WPF(1) 自定义面板-阶梯状面板

wpf中提供了几个内置的布局，如StackPanel,Grid,DockPanel,Canvas等,其实也可以继承自Panel并重写MeasureOverride和ArrangeOverride方法自定义一个面板中的元素布局格式，例子：

 

窗口缩小后：

 

图中最外面是一个自定义面板StairPanel,  其中1，2，3处分别为三个子元素，2为按钮，1和3又是StairPanel, 其中分别又有四个按钮，仍然是阶梯状布局。

当窗口大小改变后是自适应的。

xaml:

　　<Window x:Class="WpfApplication1._24.Window1"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApplication1._24"
        mc:Ignorable="d"
        Title="Window1" Height="800" Width="800">
    <Window.Resources>
        <Style x:Key="Style2" TargetType="{x:Type Button}">
            <Setter Property="Background">
                <Setter.Value>
                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                        <GradientStop Color="#FF1467C2" Offset="0"/>
                        <GradientStop Color="#FFAAC5E2" Offset="1"/>
                    </LinearGradientBrush>
                </Setter.Value>
            </Setter>
        </Style>
        <Style x:Key="Style1" TargetType="{x:Type local:StairPanel}">
            <Setter Property="Background">
                <Setter.Value>
                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                        <GradientStop Color="#FFDD8116" Offset="0"/>
                        <GradientStop Color="#FF0DBD2F" Offset="1"/>
                    </LinearGradientBrush>
                </Setter.Value>
            </Setter>
        </Style>
        <Style x:Key="Style3" TargetType="{x:Type Button}">
            <Setter Property="Background">
                <Setter.Value>
                    <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0">
                        <GradientStop Color="#FFDD8116" Offset="0"/>
                        <GradientStop Color="#FF0DBD2F" Offset="1"/>
                    </LinearGradientBrush>
                </Setter.Value>
            </Setter>
        </Style>
    </Window.Resources>
    <local:StairPanel>
        <local:StairPanel Style="{DynamicResource Style1}">
            <Button x:Name="Button1_1" Content="Button1.1" Style="{DynamicResource Style2}"/>
            <Button x:Name="Button1_2" Content="Button1.2" Style="{DynamicResource Style2}"/>
            <Button x:Name="Button1_3" Content="Button1.3" Style="{DynamicResource Style2}"/>
            <Button x:Name="Button1_4" Content="Button1.4" Style="{DynamicResource Style2}"/>
        </local:StairPanel>
        <Button x:Name="Button2" Content="Button2" FontSize="22" Style="{DynamicResource Style3}"/>
        <local:StairPanel Style="{DynamicResource Style1}">
            <Button x:Name="Button3_1" Content="Button3.1" Style="{DynamicResource Style2}"/>
            <Button x:Name="Button3_2" Content="Button3.2" Style="{DynamicResource Style2}"/>
            <Button x:Name="Button3_3" Content="Button3.3" Style="{DynamicResource Style2}"/>
            <Button x:Name="Button3_4" Content="Button3.4" Style="{DynamicResource Style2}"/>
        </local:StairPanel>

    </local:StairPanel>
</Window>

cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;

namespace WpfApplication1._24
{
    public class StairPanel : Panel
    {
        // Default public constructor
        public StairPanel()
            : base()
        {
        }

        // Override the default Measure method of Panel
        protected override Size MeasureOverride(Size availableSize)
        {
            Size panelDesiredSize = new Size();

            foreach (UIElement child in InternalChildren)
            {
                child.Measure(availableSize);
                panelDesiredSize = child.DesiredSize;
            }

            return panelDesiredSize;
        }
        protected override Size ArrangeOverride(Size finalSize)
        {
            //根据面板的大小和子元素个数等分宽度和高度
            double stepWidth = finalSize.Width / InternalChildren.Count;
            double stepHeight = finalSize.Height / InternalChildren.Count;


            double x = 0;
            double y = 0;

            foreach (UIElement child in InternalChildren)
            {
                child.Arrange(new Rect(new Point(x, y), new Size(stepWidth, stepHeight)));

　　　　 //递增子元素位置
                x += stepWidth;
                y += stepHeight;
            }
            return finalSize;
        }
    }
}