重新想象 Windows 8 Store Apps (10) - 控件之 ScrollViewer 特性: Chaining, Rail, Inertia, Snap, Zoom

原文:重新想象 Windows 8 Store Apps (10) - 控件之 ScrollViewer 特性: Chaining, Rail, Inertia, Snap, Zoom[源码下载]

[align=center]重新想象 Windows 8 Store Apps (10) - 控件之 ScrollViewer 特性: Chaining, Rail, Inertia, Snap, Zoom[/align]

作者：webabcd

介绍
重新想象 Windows 8 Store Apps 之 ScrollViewer

Chaining - 锁链

Rail - 轨道

Inertia - 惯性

Snap - 对齐

Zoom - 缩放

示例
1、演示 ScrollViewer 的 Chaining 特性
ScrollViewer/Chaining.xaml

<Page
x:Class="XamlDemo.Controls.ScrollViewer.Chaining"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:XamlDemo.Controls.ScrollViewer"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">

<Grid Background="Transparent">
<StackPanel Margin="120 0 0 0">

<ScrollViewer>
<StackPanel>

<TextBlock Text="我是参照物" FontSize="14.667" />

<!--
Chaining: 锁链，在触摸模式下，滚动本 ScrollViewer 如果超出了边界，则滚动其父 ScrollViewer
本例的测试方法：在触摸模式下，滚动 ScrollViewer 内的内容直至超出边界，超出边界后不要停下来继续滚动，通过“我是参照物”观察父 ScrollViewer 是否也被滚动

IsHorizontalScrollChainingEnabled - 是否启用水平方向上的 Chaining，默认值为 true
IsVerticalScrollChainingEnabled - 是否启用垂直方向上的 Chaining，默认值为 true
-->

<ScrollViewer Name="scrollViewer" Width="400" Height="400" Margin="0 10 0 0" HorizontalAlignment="Left"
HorizontalScrollMode="Enabled" VerticalScrollMode="Enabled"
HorizontalScrollBarVisibility="Visible" VerticalScrollBarVisibility="Visible"
IsHorizontalScrollChainingEnabled="{Binding IsChecked, ElementName=chkIsHorizontalScrollChainingEnabled}"
IsVerticalScrollChainingEnabled="{Binding IsChecked, ElementName=chkIsVerticalScrollChainingEnabled}">
<Image Source="/Assets/Logo.png" Width="1000" />
</ScrollViewer>

<StackPanel Orientation="Horizontal">
<CheckBox Name="chkIsHorizontalScrollChainingEnabled" Content="IsHorizontalScrollChainingEnabled" IsChecked="True" Margin="10 0 0 0" />
<CheckBox Name="chkIsVerticalScrollChainingEnabled" Content="IsVerticalScrollChainingEnabled" IsChecked="True" Margin="10 0 0 0" />
</StackPanel>

</StackPanel>
</ScrollViewer>

</StackPanel>
</Grid>
</Page>

2、演示 ScrollViewer 的 Rail 特性
ScrollViewer/Rail.xaml

<Page
x:Class="XamlDemo.Controls.ScrollViewer.Rail"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:XamlDemo.Controls.ScrollViewer"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">

<Grid Background="Transparent">
<StackPanel Margin="120 0 0 0">

<!--
Rail: 轨道，在触摸模式下，假设沿水平方向滚动，则由于轨道的作用，在松手前只能延水平方向滚动（即使手指有垂直方向的滚动也无用）

IsHorizontalRailEnabled - 是否启用水平方向上的轨道，默认值为 true
IsVerticalRailEnabled - 是否启用垂直方向上的轨道，默认值为 true
-->

<ScrollViewer Name="scrollViewer2" Width="400" Height="400" Margin="0 10 0 0" HorizontalAlignment="Left"
HorizontalScrollMode="Enabled" VerticalScrollMode="Enabled"
HorizontalScrollBarVisibility="Visible" VerticalScrollBarVisibility="Visible"
IsHorizontalRailEnabled="{Binding IsChecked, ElementName=chkIsHorizontalRailEnabled}"
IsVerticalRailEnabled="{Binding IsChecked, ElementName=chkIsVerticalRailEnabled}">
<Image Source="/Assets/Logo.png" Width="1000" />
</ScrollViewer>

<StackPanel Orientation="Horizontal">
<CheckBox Name="chkIsHorizontalRailEnabled" Content="IsHorizontalRailEnabled" IsChecked="True" />
<CheckBox Name="chkIsVerticalRailEnabled" Content="IsVerticalRailEnabled" IsChecked="True" Margin="10 0 0 0" />
</StackPanel>

</StackPanel>
</Grid>
</Page>

3、演示 ScrollViewer 的 Inertia 特性
ScrollViewer/Inertia.xaml

<Page
x:Class="XamlDemo.Controls.ScrollViewer.Inertia"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:XamlDemo.Controls.ScrollViewer"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">

<Grid Background="Transparent">
<StackPanel Margin="120 0 0 0">

<!--
Inertia: 惯性，在触摸模式下，用一个加速度滚动内容，松手后内容会具有惯性滚动效果

IsScrollInertiaEnabled - 是否启用惯性效果，默认值为 true
-->

<ScrollViewer Name="scrollViewer2" Width="400" Height="400" Margin="0 10 0 0" HorizontalAlignment="Left"
HorizontalScrollMode="Enabled" VerticalScrollMode="Enabled"
HorizontalScrollBarVisibility="Visible" VerticalScrollBarVisibility="Visible"
IsScrollInertiaEnabled="{Binding IsChecked, ElementName=chkIsScrollInertiaEnabled}">
<Image Source="/Assets/Logo.png" Width="1000" />
</ScrollViewer>

<StackPanel Orientation="Horizontal">
<CheckBox Name="chkIsScrollInertiaEnabled" Content="IsScrollInertiaEnabled" IsChecked="True" />
</StackPanel>

</StackPanel>
</Grid>
</Page>

4、演示 ScrollViewer 的 Snap 特性
ScrollViewer/Snap.xaml

<Page
x:Class="XamlDemo.Controls.ScrollViewer.Snap"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:XamlDemo.Controls.ScrollViewer"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">

<Grid Background="Transparent">
<StackPanel Margin="120 0 0 0">

<!--用于设置 ScrollViewer 的 HorizontalSnapPointsType-->
<ComboBox Name="comboBox" SelectedIndex="0" SelectionChanged="ComboBox_SelectionChanged_1" HorizontalAlignment="Left">
<ComboBoxItem>HorizontalSnapPointsType = SnapPointsType.None</ComboBoxItem>
<ComboBoxItem>HorizontalSnapPointsType = SnapPointsType.Optional</ComboBoxItem>
<ComboBoxItem>HorizontalSnapPointsType = SnapPointsType.Mandatory</ComboBoxItem>
</ComboBox>

<ScrollViewer x:Name="scrollViewer" Width="400" Height="200" HorizontalAlignment="Left" Margin="0 10 0 0"
HorizontalScrollMode="Enabled" VerticalScrollMode="Enabled"
HorizontalScrollBarVisibility="Visible" VerticalScrollBarVisibility="Visible">
<StackPanel Orientation="Horizontal">
<Image Width="400" Height="200" Stretch="Fill" Source="/Assets/Logo.png" />
<Image Width="400" Height="200" Stretch="Fill" Source="/Assets/NineGrid/Demo.png" />
<Image Width="350" Height="200" Stretch="Fill" Source="/Assets/Logo.png" />
<Image Width="450" Height="200" Stretch="Fill" Source="/Assets/NineGrid/Demo.png" />
<Image Width="400" Height="200" Stretch="Fill" Source="/Assets/Logo.png" />

<TextBox Width="400" Height="200" FontSize="26.67" Text="message" Name="txtMsg"  />
<TextBox Width="400" Height="200" FontSize="26.67" Text="message2" Name="txtMsg2"  />
<TextBox Width="400" Height="200" FontSize="26.67" Text="message3" Name="txtMsg3"  />
</StackPanel>
</ScrollViewer>

<!--用于演示通过程序定位到 ScrollViewer 内的指定元素-->
<Button Content="滚动到 txtMsg2" Click="Button_Click_1" Margin="0 10 0 0" />

</StackPanel>
</Grid>
</Page>

ScrollViewer/Snap.xaml.cs

/*
* Snap: 对齐，在触摸模式下，如果 ScrollViewer 有多个元素，在滚动结束后会定位到其中某一个具体的元素，这就叫对齐
*
* HorizontalSnapPointsType - 水平方向上的对齐行为，Windows.UI.Xaml.Controls.SnapPointsType枚举
*     SnapPointsType.None - 不需要对齐，默认值
*     SnapPointsType.Optional - 看情况，如果离某个元素很近则对齐此元素
*     SnapPointsType.Mandatory - 强制对齐，必须对齐到某一元素
*     SnapPointsType.OptionalSingle - 仅对 Zoom 对齐有用
*     SnapPointsType.MandatorySingle - 仅对 Zoom 对齐有用
* VerticalSnapPointsType - 垂直方向上的对齐行为
*
*
* HorizontalSnapPointsAlignment - 水平方向上的对齐方式，Windows.UI.Xaml.Controls.Primitives.SnapPointsAlignment枚举
*     SnapPointsAlignment.Near - 元素的左侧对齐 ScrollViewer 的左侧边界，默认值
*     SnapPointsAlignment.Center - 元素的中心点对齐 ScrollViewer 的中心点
*     SnapPointsAlignment.Far - 元素的右侧对齐 ScrollViewer 的右侧边界
* VerticalSnapPointsAlignment - 垂直方向上的对齐方式
*
*
* BringIntoViewOnFocusChange - ScrollViewer 内的某元素获得焦点后，是否需要定位到此元素，默认值为 true
*/

using Windows.UI.Xaml.Controls;

namespace XamlDemo.Controls.ScrollViewer
{
public sealed partial class Snap : Page
{
public Snap()
{
this.InitializeComponent();

this.Loaded += Snap_Loaded;
}

void Snap_Loaded(object sender, Windows.UI.Xaml.RoutedEventArgs e)
{
scrollViewer.HorizontalSnapPointsAlignment = Windows.UI.Xaml.Controls.Primitives.SnapPointsAlignment.Near;
scrollViewer.BringIntoViewOnFocusChange = true;
}

private void ComboBox_SelectionChanged_1(object sender, SelectionChangedEventArgs e)
{
if (scrollViewer != null && comboBox != null)
{
switch (comboBox.SelectedIndex)
{
case 0:
scrollViewer.HorizontalSnapPointsType = SnapPointsType.None;
break;
case 1:
scrollViewer.HorizontalSnapPointsType = SnapPointsType.Optional;
break;
case 3:
scrollViewer.HorizontalSnapPointsType = SnapPointsType.Mandatory;
break;
default:
scrollViewer.HorizontalSnapPointsType = SnapPointsType.None;
break;
}
}
}

private void Button_Click_1(object sender, Windows.UI.Xaml.RoutedEventArgs e)
{
// 当 BringIntoViewOnFocusChange 为 true 时，如果 txtMsg2 获得焦点，则 ScrollViewer 会自动滚动到 txtMsg2
txtMsg2.Focus(Windows.UI.Xaml.FocusState.Programmatic);
}
}
}

5、演示 ScrollViewer 的 Zoom 特性
ScrollViewer/Zoom.xaml

<Page
x:Class="XamlDemo.Controls.ScrollViewer.Zoom"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:XamlDemo.Controls.ScrollViewer"
xmlns:sys="using:System"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d">

<Grid Background="Transparent">
<StackPanel Margin="120 0 0 0">

<!--
Zoom - 放大/缩小

ZoomMode - 是否启用“放大/缩小”功能（Disabled, Enabled），默认值为 Enabled
MaxZoomFactor - 内容放大的最大倍数，默认值 10
MinZoomFactor - 内容放大的最小倍数，默认值 0.1
-->
<ScrollViewer Name="scrollViewer" Width="400" Height="400" HorizontalAlignment="Left"
ZoomMode="Enabled" MaxZoomFactor="2" MinZoomFactor="0.5">
<Image Source="/Assets/Logo.png" Width="400" Height="400" />
</ScrollViewer>

<Button Click="Button_Click_1" Content="放大/缩小到 0.1 倍" />

</StackPanel>
</Grid>
</Page>

ScrollViewer/Zoom.xaml.cs

using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

namespace XamlDemo.Controls.ScrollViewer
{
public sealed partial class Zoom : Page
{
public Zoom()
{
this.InitializeComponent();

this.Loaded += Zoom_Loaded;
}

void Zoom_Loaded(object sender, RoutedEventArgs e)
{
/*
* ZoomSnapPoints - “放大/缩小”的对齐点的集合，默认是空的
*
* ZoomSnapPointsType - “放大/缩小”的对齐行为
*     SnapPointsType.None - 不需要对齐，默认值
*     SnapPointsType.Optional - 看情况，如果离某个对齐点很近则对齐
*     SnapPointsType.Mandatory - 强制对齐，必须对齐到某一个对齐点
*     SnapPointsType.OptionalSingle - 同 Optional，但不能跳过对齐点
*     SnapPointsType.MandatorySingle - 同 Mandatory，但不能跳过对齐点
*
* IsZoomChainingEnabled - 是否启用 Zoom 的 Chaining
* IsZoomInertiaEnabled - 是否启用 Zoom 的 Inertia
* ZoomFactor - 获取当前的 Zoom 的倍数
*
* ZoomToFactor() - Zoom 到指定的倍数
*/

scrollViewer.ZoomSnapPointsType = SnapPointsType.OptionalSingle;

scrollViewer.ZoomSnapPoints.Add(0.5f);
scrollViewer.ZoomSnapPoints.Add(0.8f);
scrollViewer.ZoomSnapPoints.Add(1.0f);
scrollViewer.ZoomSnapPoints.Add(1.5f);
scrollViewer.ZoomSnapPoints.Add(2.0f);
}

private void Button_Click_1(object sender, RoutedEventArgs e)
{
scrollViewer.ZoomToFactor(0.1f);
}
}
}

OK
[源码下载]