演练:概述

2015-05-18

通过定义控件实现的语言为基础的功能 (如概述了若要展开或折叠的文本区域。可以定义区域。语言服务中，也可以定义拥有文件扩展名与内容类型并将区域定义只应用于该类型，也可以将区域定义于现有内容类型 (例如 “text”)。本演练演示如何定义和显示大纲区域。

系统必备

若要完成本演练，您必须安装 Visual Studio 2010 SDK。

备注

有关 Visual Studio SDK 的更多信息，请参见扩展 Visual Studio 概述。若要查找有关中所列如何下载 Visual Studio SDK，请 Visual Studio Extensibility Developer Center 参见 MSDN 网站上。

创建一个 managed extensibility framework 项目 (MEF)

创建 MEF 项目

创建一个编辑分类器项目。将解决方案命名为 OutlineRegionTest。
打开在 VSIX 清单编辑器中的 source.extension.vsixmanifest 文件。
确保 Content 归为包含一个 MEF 组件内容类型，而 Path 设置为 OutlineRegionTest.dll。
保存并关闭的 source.extension.vsixmanifest。
删除现有类文件。

实现以大纲方式显示的标记

大纲区域由标记指示OutliningRegionTag()。此标记提供标准概述的行为。该大纲区域可以展开或折叠。该大纲区域由加号指示，则折叠或负号，则，将展开，然后展开的区域由竖线标定。

下面的步骤演示如何定义创建轮廓所有区域的区域分隔 “的标记 [”和 “]”。

实现以大纲方式显示的标记

将类文件并将其命名为 OutliningTagger。

导入下列命名空间。

Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Text
Imports System.ComponentModel.Composition
Imports Microsoft.VisualStudio.Text.Outlining
Imports Microsoft.VisualStudio.Text.Tagging
Imports Microsoft.VisualStudio.Utilities
Imports Microsoft.VisualStudio.Text

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel.Composition;
using Microsoft.VisualStudio.Text.Outlining;
using Microsoft.VisualStudio.Text.Tagging;
using Microsoft.VisualStudio.Utilities;
using Microsoft.VisualStudio.Text;

创建名为 OutliningTagger的类，并使它实现 ITagger:

Friend NotInheritable Class OutliningTagger
    Implements ITagger(Of IOutliningRegionTag)

internal sealed class OutliningTagger : ITagger<IOutliningRegionTag>

添加一些字段跟踪文本缓冲区，并快照和累积应标记为大纲区域的设置行。此代码包括的区域对象列表表示大纲显示区域 (稍后将定义)。

'the characters that start the outlining region 
Private startHide As String = "[" 
'the characters that end the outlining region 
Private endHide As String = "]" 
'the characters that are displayed when the region is collapsed 
Private ellipsis As String = "..." 
'the contents of the tooltip for the collapsed span 
Private hoverText As String = "hover text" 
Private buffer As ITextBuffer
Private snapshot As ITextSnapshot
Private regions As List(Of Region)

string startHide = "[";     //the characters that start the outlining region 
string endHide = "]";       //the characters that end the outlining region 
string ellipsis = "...";    //the characters that are displayed when the region is collapsed 
string hoverText = "hover text"; //the contents of the tooltip for the collapsed span
ITextBuffer buffer;
ITextSnapshot snapshot;
List<Region> regions;

将字段初始化，分析缓冲区，并添加事件处理程序。 Changed 事件的一个标记构造函数。

Public Sub New(ByVal buffer As ITextBuffer)
    Me.buffer = buffer
    Me.snapshot = buffer.CurrentSnapshot
    Me.regions = New List(Of Region)()
    Me.ReParse()
    AddHandler Me.buffer.Changed, AddressOf BufferChanged
End Sub

public OutliningTagger(ITextBuffer buffer)
{
    this.buffer = buffer;
    this.snapshot = buffer.CurrentSnapshot;
    this.regions = new List<Region>();
    this.ReParse();
    this.buffer.Changed += BufferChanged;
}

执行 GetTags 方法，实例化标记范围。此示例假定，在 NormalizedSpanCollection 的范围传递给方法是连续的，不过，这可能并非始终用例。该方法实例化每个的新标记范围大纲显示区域。

Public Function GetTags(ByVal spans As NormalizedSnapshotSpanCollection) As IEnumerable(Of ITagSpan(Of IOutliningRegionTag)) Implements ITagger(Of Microsoft.VisualStudio.Text.Tagging.IOutliningRegionTag).GetTags
    If spans.Count = 0 Then 
        Return Nothing 
        Exit Function 
    End If 
    Dim currentRegions As List(Of Region) = Me.regions
    Dim currentSnapshot As ITextSnapshot = Me.snapshot
    Dim entire As SnapshotSpan = New SnapshotSpan(spans(0).Start, spans(spans.Count - 1).[End]).TranslateTo(currentSnapshot, SpanTrackingMode.EdgeExclusive)
    Dim startLineNumber As Integer = entire.Start.GetContainingLine().LineNumber
    Dim endLineNumber As Integer = entire.[End].GetContainingLine().LineNumber

    Dim list As List(Of ITagSpan(Of IOutliningRegionTag))
    list = New List(Of ITagSpan(Of IOutliningRegionTag))()

    For Each region In currentRegions
        If region.StartLine <= endLineNumber AndAlso region.EndLine >= startLineNumber Then 
            Dim startLine = currentSnapshot.GetLineFromLineNumber(region.StartLine)
            Dim endLine = currentSnapshot.GetLineFromLineNumber(region.EndLine)

            'the region starts at the beginning of the "[", and goes until the *end* of the line that contains the "]".
            list.Add(New TagSpan(Of IOutliningRegionTag)(New SnapshotSpan(startLine.Start + region.StartOffset, endLine.End),
            New OutliningRegionTag(False, False, ellipsis, hoverText)))
        End If 
    Next 
    Return list
End Function

public IEnumerable<ITagSpan<IOutliningRegionTag>> GetTags(NormalizedSnapshotSpanCollection spans)
{
    if (spans.Count == 0)
        yield break;
    List<Region> currentRegions = this.regions;
    ITextSnapshot currentSnapshot = this.snapshot;
    SnapshotSpan entire = new SnapshotSpan(spans[0].Start, spans[spans.Count - 1].End).TranslateTo(currentSnapshot, SpanTrackingMode.EdgeExclusive);
    int startLineNumber = entire.Start.GetContainingLine().LineNumber;
    int endLineNumber = entire.End.GetContainingLine().LineNumber;
    foreach (var region in currentRegions)
    {
        if (region.StartLine <= endLineNumber &&
            region.EndLine >= startLineNumber)
        {
            var startLine = currentSnapshot.GetLineFromLineNumber(region.StartLine);
            var endLine = currentSnapshot.GetLineFromLineNumber(region.EndLine);

            //the region starts at the beginning of the "[", and goes until the *end* of the line that contains the "]".
            yield return new TagSpan<IOutliningRegionTag>(
                new SnapshotSpan(startLine.Start + region.StartOffset,
                endLine.End),
                new OutliningRegionTag(false, false, ellipsis, hoverText));
        }
    }
}

声明 TagsChanged 事件处理程序。

Public Event TagsChanged As EventHandler(Of SnapshotSpanEventArgs) Implements ITagger(Of IOutliningRegionTag).TagsChanged

public event EventHandler<SnapshotSpanEventArgs> TagsChanged;

添加响应 Changed 事件通过分析文本缓冲区中的一个 BufferChanged 事件处理程序。

Private Sub BufferChanged(ByVal sender As Object, ByVal e As TextContentChangedEventArgs)
    ' If this isn't the most up-to-date version of the buffer, then ignore it for now (we'll eventually get another change event). 
    If e.After IsNot buffer.CurrentSnapshot Then 
        Exit Sub 
    End If 
    Me.ReParse()
End Sub

void BufferChanged(object sender, TextContentChangedEventArgs e)
{
    // If this isn't the most up-to-date version of the buffer, then ignore it for now (we'll eventually get another change event). 
    if (e.After != buffer.CurrentSnapshot)
        return;
    this.ReParse();
}

添加分析缓冲区的方法。上述示例此处仅用于图。它同步分析缓冲区到嵌套的大纲显示区域。

Private Sub ReParse()
    Dim newSnapshot As ITextSnapshot = buffer.CurrentSnapshot
    Dim newRegions As New List(Of Region)()

    'keep the current (deepest) partial region, which will have 
    ' references to any parent partial regions. 
    Dim currentRegion As PartialRegion = Nothing 

    For Each line In newSnapshot.Lines
        Dim regionStart As Integer = -1
        Dim text As String = line.GetText()

        'lines that contain a "[" denote the start of a new region. 
        If text.IndexOf(startHide, StringComparison.Ordinal) <> -1 Then
            regionStart = text.IndexOf(startHide, StringComparison.Ordinal)
            Dim currentLevel As Integer = If((currentRegion IsNot Nothing), currentRegion.Level, 1)
            Dim newLevel As Integer 
            If Not TryGetLevel(text, regionStart, newLevel) Then
                newLevel = currentLevel + 1
            End If 

            'levels are the same and we have an existing region; 
            'end the current region and start the next 
            If currentLevel = newLevel AndAlso currentRegion IsNot Nothing Then 
                Dim newRegion = New Region()
                newRegion.Level = currentRegion.Level
                newRegion.StartLine = currentRegion.StartLine
                newRegion.StartOffset = currentRegion.StartOffset
                newRegion.EndLine = line.LineNumber
                newRegions.Add(newRegion)

                currentRegion = New PartialRegion()
                currentRegion.Level = newLevel
                currentRegion.StartLine = line.LineNumber
                currentRegion.StartOffset = regionStart
                currentRegion.PartialParent = currentRegion.PartialParent

            Else 
                'this is a new (sub)region
                currentRegion = New PartialRegion()
                currentRegion.Level = newLevel
                currentRegion.StartLine = line.LineNumber
                currentRegion.StartOffset = regionStart
                currentRegion.PartialParent = currentRegion
            End If 
            'lines that contain "]" denote the end of a region 
        ElseIf (text.IndexOf(endHide, StringComparison.Ordinal)) <> -1 Then
            regionStart = text.IndexOf(endHide, StringComparison.Ordinal)
            Dim currentLevel As Integer = If((currentRegion IsNot Nothing), currentRegion.Level, 1)
            Dim closingLevel As Integer 
            If Not TryGetLevel(text, regionStart, closingLevel) Then
                closingLevel = currentLevel
            End If 

            'the regions match 
            If currentRegion IsNot Nothing AndAlso currentLevel = closingLevel Then 
                Dim newRegion As Region
                newRegion = New Region()
                newRegion.Level = currentLevel
                newRegion.StartLine = currentRegion.StartLine
                newRegion.StartOffset = currentRegion.StartOffset
                newRegion.EndLine = line.LineNumber
                newRegions.Add(newRegion)

                currentRegion = currentRegion.PartialParent
            End If 
        End If 
    Next 
    'determine the changed span, and send a changed event with the new spans 
    Dim oldSpans As New List(Of Span)(Me.regions.[Select](Function(r) AsSnapshotSpan(r, Me.snapshot).TranslateTo(newSnapshot, SpanTrackingMode.EdgeExclusive).Span))
    Dim newSpans As New List(Of Span)(newRegions.[Select](Function(r) AsSnapshotSpan(r, newSnapshot).Span))

    Dim oldSpanCollection As New NormalizedSpanCollection(oldSpans)
    Dim newSpanCollection As New NormalizedSpanCollection(newSpans)

    'the changed regions are regions that appear in one set or the other, but not both. 
    Dim removed As NormalizedSpanCollection = NormalizedSpanCollection.Difference(oldSpanCollection, newSpanCollection)

    Dim changeStart As Integer = Integer.MaxValue
    Dim changeEnd As Integer = -1

    If removed.Count > 0 Then
        changeStart = removed(0).Start
        changeEnd = removed(removed.Count - 1).[End]
    End If 

    If newSpans.Count > 0 Then
        changeStart = Math.Min(changeStart, newSpans(0).Start)
        changeEnd = Math.Max(changeEnd, newSpans(newSpans.Count - 1).[End])
    End If 

    Me.snapshot = newSnapshot
    Me.regions = newRegions

    If changeStart <= changeEnd Then 
        Dim snap As ITextSnapshot = Me.snapshot
        RaiseEvent TagsChanged(Me, New SnapshotSpanEventArgs(New SnapshotSpan(Me.snapshot, Span.FromBounds(changeStart, changeEnd))))
    End If 
End Sub

void ReParse()
{
    ITextSnapshot newSnapshot = buffer.CurrentSnapshot;
    List<Region> newRegions = new List<Region>();

    //keep the current (deepest) partial region, which will have 
    // references to any parent partial regions.
    PartialRegion currentRegion = null;

    foreach (var line in newSnapshot.Lines)
    {
        int regionStart = -1;
        string text = line.GetText();

        //lines that contain a "[" denote the start of a new region.
        if ((regionStart = text.IndexOf(startHide, StringComparison.Ordinal)) != -1)
        {
            int currentLevel = (currentRegion != null) ? currentRegion.Level : 1;
            int newLevel;
            if (!TryGetLevel(text, regionStart, out newLevel))
                newLevel = currentLevel + 1;

            //levels are the same and we have an existing region; 
            //end the current region and start the next 
            if (currentLevel == newLevel && currentRegion != null)
            {
                newRegions.Add(new Region()
                {
                    Level = currentRegion.Level,
                    StartLine = currentRegion.StartLine,
                    StartOffset = currentRegion.StartOffset,
                    EndLine = line.LineNumber
                });

                currentRegion = new PartialRegion()
                {
                    Level = newLevel,
                    StartLine = line.LineNumber,
                    StartOffset = regionStart,
                    PartialParent = currentRegion.PartialParent
                };
            }
            //this is a new (sub)region 
            else
            {
                currentRegion = new PartialRegion()
                {
                    Level = newLevel,
                    StartLine = line.LineNumber,
                    StartOffset = regionStart,
                    PartialParent = currentRegion
                };
            }
        }
        //lines that contain "]" denote the end of a region
        else if ((regionStart = text.IndexOf(endHide, StringComparison.Ordinal)) != -1)
        {
            int currentLevel = (currentRegion != null) ? currentRegion.Level : 1;
            int closingLevel;
            if (!TryGetLevel(text, regionStart, out closingLevel))
                closingLevel = currentLevel;

            //the regions match 
            if (currentRegion != null &&
                currentLevel == closingLevel)
            {
                newRegions.Add(new Region()
                {
                    Level = currentLevel,
                    StartLine = currentRegion.StartLine,
                    StartOffset = currentRegion.StartOffset,
                    EndLine = line.LineNumber
                });

                currentRegion = currentRegion.PartialParent;
            }
        }
    }

    //determine the changed span, and send a changed event with the new spans
    List<Span> oldSpans =
        new List<Span>(this.regions.Select(r => AsSnapshotSpan(r, this.snapshot)
            .TranslateTo(newSnapshot, SpanTrackingMode.EdgeExclusive)
            .Span));
    List<Span> newSpans =
            new List<Span>(newRegions.Select(r => AsSnapshotSpan(r, newSnapshot).Span));

    NormalizedSpanCollection oldSpanCollection = new NormalizedSpanCollection(oldSpans);
    NormalizedSpanCollection newSpanCollection = new NormalizedSpanCollection(newSpans);

    //the changed regions are regions that appear in one set or the other, but not both.
    NormalizedSpanCollection removed =
    NormalizedSpanCollection.Difference(oldSpanCollection, newSpanCollection);

    int changeStart = int.MaxValue;
    int changeEnd = -1;

    if (removed.Count > 0)
    {
        changeStart = removed[0].Start;
        changeEnd = removed[removed.Count - 1].End;
    }

    if (newSpans.Count > 0)
    {
        changeStart = Math.Min(changeStart, newSpans[0].Start);
        changeEnd = Math.Max(changeEnd, newSpans[newSpans.Count - 1].End);
    }

    this.snapshot = newSnapshot;
    this.regions = newRegions;

    if (changeStart <= changeEnd)
    {
        ITextSnapshot snap = this.snapshot;
        if (this.TagsChanged != null)
            this.TagsChanged(this, new SnapshotSpanEventArgs(
                new SnapshotSpan(this.snapshot, Span.FromBounds(changeStart, changeEnd))));
    }
}

下面的帮助器方法获取表示大纲级别的整数，因此 1 是最左侧的大括号对。

Private Shared Function TryGetLevel(ByVal text As String, ByVal startIndex As Integer, ByRef level As Integer) As Boolean
    level = -1
    If text.Length > startIndex + 3 Then 
        If Integer.TryParse(text.Substring(startIndex + 1), level) Then 
            Return True 
        End If 
    End If 

    Return False 
End Function

static bool TryGetLevel(string text, int startIndex, out int level)
{
    level = -1;
    if (text.Length > startIndex + 3)
    {
        if (int.TryParse(text.Substring(startIndex + 1), out level))
            return true;
    }

    return false;
}

下面的帮助器方法将区域 (本主题稍后部分进行了定义) 转换为 SnapshotSpan。

Private Shared Function AsSnapshotSpan(ByVal region As Region, ByVal snapshot As ITextSnapshot) As SnapshotSpan
    Dim startLine = snapshot.GetLineFromLineNumber(region.StartLine)
    Dim endLine = If((region.StartLine = region.EndLine), startLine, snapshot.GetLineFromLineNumber(region.EndLine))
    Return New SnapshotSpan(startLine.Start + region.StartOffset, endLine.[End])
End Function

static SnapshotSpan AsSnapshotSpan(Region region, ITextSnapshot snapshot)
{
    var startLine = snapshot.GetLineFromLineNumber(region.StartLine);
    var endLine = (region.StartLine == region.EndLine) ? startLine
         : snapshot.GetLineFromLineNumber(region.EndLine);
    return new SnapshotSpan(startLine.Start + region.StartOffset, endLine.End);
}

下面的代码仅用于图。它定义一个包含大纲区域起始处的行号和扭曲的 PartialRegion 类，并对父区域 (如果有)。这使得分析程序设置嵌套大纲区域。派生的区域类包含对一个大纲区域的末尾的行号。

Private Class PartialRegion
    Private _StartLine As Integer 
    Public Property StartLine() As Integer 
        Get 
            Return _StartLine
        End Get 
        Set(ByVal value As Integer)
            _StartLine = value
        End Set 
    End Property 
    Private _StartOffset As Integer 
    Public Property StartOffset() As Integer 
        Get 
            Return _StartOffset
        End Get 
        Set(ByVal value As Integer)
            _StartOffset = value
        End Set 
    End Property 
    Private _Level As Integer 
    Public Property Level() As Integer 
        Get 
            Return _Level
        End Get 
        Set(ByVal value As Integer)
            _Level = value
        End Set 
    End Property 
    Private _PartialParent As PartialRegion
    Public Property PartialParent() As PartialRegion
        Get 
            Return _PartialParent
        End Get 
        Set(ByVal value As PartialRegion)
            _PartialParent = value
        End Set 
    End Property 
End Class 

Private Class Region
    Inherits PartialRegion
    Private _EndLine As Integer 
    Public Property EndLine() As Integer 
        Get 
            Return _EndLine
        End Get 
        Set(ByVal value As Integer)
            _EndLine = value
        End Set 
    End Property 
End Class

class PartialRegion
{
    public int StartLine { get; set; }
    public int StartOffset { get; set; }
    public int Level { get; set; }
    public PartialRegion PartialParent { get; set; }
}

class Region : PartialRegion
{
    public int EndLine { get; set; }
}

实现标记提供程序

必须导出该标记的一个标记提供程序。，如果缓冲区已经有一，标记创建提供程序 “text”内容类型的缓冲区的 OutliningTagger ，或者返回 OutliningTagger 。

实现标记提供程序

创建实现 ITaggerProvider名为 OutliningTaggerProvider 的类，并将其导出与 ContentType 和 TagType 属性。

<Export(GetType(ITaggerProvider))> _
<TagType(GetType(IOutliningRegionTag))> _
<ContentType("text")> _
Friend NotInheritable Class OutliningTaggerProvider
    Implements ITaggerProvider

[Export(typeof(ITaggerProvider))]
[TagType(typeof(IOutliningRegionTag))]
[ContentType("text")]
internal sealed class OutliningTaggerProvider : ITaggerProvider

通过添加 OutliningTagger 执行 CreateTagger``1 方法添加到缓冲区的属性。

Public Function CreateTagger(Of T As ITag)(ByVal buffer As ITextBuffer) As ITagger(Of T) Implements ITaggerProvider.CreateTagger
    'create a single tagger for each buffer. 
    Dim sc As Func(Of ITagger(Of T)) = Function() TryCast(New OutliningTagger(buffer), ITagger(Of T))
    Return buffer.Properties.GetOrCreateSingletonProperty(Of ITagger(Of T))(sc)
End Function

public ITagger<T> CreateTagger<T>(ITextBuffer buffer) where T : ITag
{
    //create a single tagger for each buffer.
    Func<ITagger<T>> sc = delegate() { return new OutliningTagger(buffer) as ITagger<T>; };
    return buffer.Properties.GetOrCreateSingletonProperty<ITagger<T>>(sc);
}

生成并测试代码

若要测试此代码，请生成 OutlineRegionTest 解决方案并运行在的实验实例。

生成和测试 OutlineRegionTest 解决方案

生成解决方案。
当您运行在调试器中查看此项目， Visual Studio 的第二个实例进行实例化。
创建文本文件。键入包括左大括号和一个右大括号的某些文本。
```
[
   Hello
]
```
应具有包含两个大括号的一个大纲区域。您应当能够在左大括号左侧单击减号您可以展开大纲区域。在该区域折叠时，省略号 (...) 符号应处于个折叠区域的左边，，而 popup 包含文本 悬停文本 应显示您沿省略号的指针。

请参见

任务

演练:链接到文件扩展名的内容类型

通过

演练:概述

系统必备

创建一个 managed extensibility framework 项目 (MEF)

创建 MEF 项目

实现以大纲方式显示的标记

实现以大纲方式显示的标记

实现标记提供程序

实现标记提供程序

生成并测试代码

生成和测试 OutlineRegionTest 解决方案

请参见

任务

其他资源