<Toolkit>———LockablePivot

Toolkit中LockablePivot的外部属性、方法如下：

namespace Microsoft.Phone.Controls
{
    // Summary:
    //     The lockable Pivot extends the base Pivot control with a property that disables
    //     navigation between Pivot items.
    [StyleTypedProperty(Property = "ItemContainerStyle", StyleTargetType = typeof(PivotItem))]
    [TemplatePart(Name = "HeadersListElement", Type = typeof(PivotHeadersControl))]
    [TemplatePart(Name = "PivotItemPresenter", Type = typeof(ItemsPresenter))]
    public class LockablePivot : Pivot
    {
        // Summary:
        //     Identifies the IsLocked dependency property.
        public static readonly DependencyProperty IsLockedProperty;

        // Summary:
        //     Initializes a new instance of the LockablePivot type.
        public LockablePivot();

        // Summary:
        //     Gets or sets a value indicating whether the control is locked.
        public bool IsLocked { get; set; }

        // Summary:
        //     Invoked when the Items property changes.
        //
        // Parameters:
        //   e:
        //     Information about the change.
        protected override void OnItemsChanged(NotifyCollectionChangedEventArgs e);
    }
}

从中我们只看出LockablePivot是继承自Pivot，并且只有一个IsLocked属性可以用，所以可知LockablePivot使用和Pivot基本一致。

下面我们看一下IsLocked使用效果：

（未锁效果，可左右滑动）                             （锁住效果，这个时候LockablePivot中只有一个PivotItem）

锁住的时候为什么LockablePivot只有一个PivotItem呢？

其实我们把LockablePivot反编译一下就知道原因了。（下面是一段反编译代码）

private void OnIsLockedChanged(bool newValue)
{
    this._isLocked = newValue;
    this._isUpdating = true;
    if (this._isLocked)
    {
        this._savedIndex = base.get_SelectedIndex();
        this.FadeOutHeaders();
        this.SaveAndRemoveItems();
    }
    else
    {
        this.RestoreItems();
        this.FadeInHeaders();
    }
    this._isUpdating = false;
}

 

从中我们可以看出LockablePivot的实现原理：

　　当IsLocked设置为true的时候，LockablePivot会保存当前的PivotItem项，然后把其他的PivotItem从LockablePivot中移除保存起来。

　　当IsLocked设置为false的时候再将保存的PivotItem移回LockablePivot中。

下面是一个LockablePivot的简单使用例子：

<phone:PhoneApplicationPage 
    x:Class="TestLstBoxDemo.TestPage.TestCtrlPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    mc:Ignorable="d" d:DesignHeight="696" d:DesignWidth="480"
    shell:SystemTray.IsVisible="True" 
    xmlns:toolkit="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Toolkit" 
    xmlns:controls="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls"
    xmlns:my="clr-namespace:SinOrMulListBox;assembly=SinOrMulListBox" 
    d:DataContext="{d:DesignData ../Design/ViewModelSampleData.xaml}">

    <!--LayoutRoot is the root grid where all page content is placed-->
    <toolkit:LockablePivot x:Name="LockPivot" Title="Use LockablePivot">
        <toolkit:LockablePivot.Resources>
            <ResourceDictionary>
                <Style TargetType="TextBlock" x:Key="TBlock">
                    <Setter Property="Margin" Value="0,0,0,-10"/>
                    <Setter Property="FontSize" Value="60"/>
                </Style>
            </ResourceDictionary>
        </toolkit:LockablePivot.Resources>
        <controls:PivotItem>
            <controls:PivotItem.Header>
                <TextBlock Text="LockItem1" Style="{StaticResource TBlock}"/>
            </controls:PivotItem.Header>
            <Grid>
                <my:SinOrMulListBox Name="listBoxWithBoxes" Margin="0,0,0,0"  IsMultipleSelect="True" ItemsSource="{Binding SimpleModels}">
                    <my:SinOrMulListBox.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Orientation="Horizontal" Margin="0,0,0,20">
                                <Rectangle Height="100" Width="100" Fill="#FFE5001b" Margin="0,0,9,0"/>
                                <StackPanel>
                                    <TextBlock Text="{Binding Name}" TextWrapping="Wrap" Style="{StaticResource PhoneTextLargeStyle}"/>
                                    <TextBlock Text="{Binding Description}" TextWrapping="Wrap" Margin="12,-6,12,0" Style="{StaticResource PhoneTextSubtleStyle}"/>
                                </StackPanel>
                            </StackPanel>
                        </DataTemplate>
                    </my:SinOrMulListBox.ItemTemplate>
                </my:SinOrMulListBox>
            </Grid>
        </controls:PivotItem>
        <controls:PivotItem>
            <controls:PivotItem.Header>
                <TextBlock Text="LockItem2" Style="{StaticResource TBlock}"/>
            </controls:PivotItem.Header>
            <Grid />
        </controls:PivotItem>
    </toolkit:LockablePivot>

    <!--Sample code showing usage of ApplicationBar-->
    <phone:PhoneApplicationPage.ApplicationBar>
        <shell:ApplicationBar IsVisible="True" IsMenuEnabled="True">
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button1.png" Text="Lock" Click="Lock_Click"/>
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button1.png" Text="UnLock" Click="UnLock_Click"/>

            <shell:ApplicationBar.MenuItems>
                <shell:ApplicationBarMenuItem Text="开启单选" Click="ApplicationBarMenuItem_Click"/>
                <shell:ApplicationBarMenuItem Text="开启多选" Click="ApplicationBarMenuItem_Click_1"/>
            </shell:ApplicationBar.MenuItems>
        </shell:ApplicationBar>
    </phone:PhoneApplicationPage.ApplicationBar>

</phone:PhoneApplicationPage>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;

namespace TestLstBoxDemo.TestPage
{
    public partial class TestCtrlPage : PhoneApplicationPage
    {
        public TestCtrlPage()
        {
            InitializeComponent();

            this.Loaded += new RoutedEventHandler(LockablePivot_Loaded);
        }

        void LockablePivot_Loaded(object sender, RoutedEventArgs e)
        {
            DataContext = App.ViewModel;
        }

        protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e)
        {
            if (!App.ViewModel.IsDataLoaded)
            {
                App.ViewModel.LoadData();
            }
            base.OnNavigatedTo(e);
        }

        private void Lock_Click(object sender, EventArgs e)
        {
            this.LockPivot.IsLocked = true;
        }

        private void UnLock_Click(object sender, EventArgs e)
        {
            this.LockPivot.IsLocked = false;
        }

        //开启单选
        private void ApplicationBarMenuItem_Click(object sender, EventArgs e)
        {
            listBoxWithBoxes.IsMultipleSelect = false;
        }
        //开启多选
        private void ApplicationBarMenuItem_Click_1(object sender, EventArgs e)
        {
            listBoxWithBoxes.IsMultipleSelect = true;
        }
    }
}

源码