前言
本文将介绍另一个与编辑器相关的例子PropertyManager。
问题分析
PropertyManager用来管理代码中的属性。我们在C# 3.0之前编写代码时,与属性相关的主要操作是将字段封装为属性,VS 2005中的Refactor->Encapsulate Field菜单(快捷键Ctrl+R, E)可以简化这个操作。它每次封装一个字段,并将生成的属性放在字段所在行的下一行,但是大部分人的编码习惯是将字段放在一起,将属性们放在一起,所以首先PropertyManager要做到这一点。
C#3.0引入了自动属性的特性,使得我们在处理简单属性的时候更为简单。但是我们有时候还是需要使用传统风格的属性声明方式,PropertyManager还要能在这两种声明方式之间进行转化。
下面就来看看如何在Add-In中实现这些功能。
实现PropertyManager
1)添加命令
按上面的分析,这里需要三个命令,界面看起来像这样:

Batch Property为选中的多个字段生成属性代码。这里将原有的传统的声明方式称为Normal-Property,将自动属性称为Auto-Property,后面的两个命令即是在这两种方式间进行转换。
使用下面的代码添加命令:
C# Code - 添加ProjectManager命令
CommandBar codeWinCommandBar = helper.GetCommandBarByName("Code Window");
int pmPopupIndex = codeWinCommandBar.Controls.Count + 1;
CommandBarPopup pmPopup = codeWinCommandBar.Controls.Add(
MsoControlType.msoControlPopup, Type.Missing, Type.Missing,
pmPopupIndex, true) as CommandBarPopup;
pmPopup.Caption = "PropertyManager";
CommandBarButton batchPropertyCmd = helper.AddButtonToPopup
(pmPopup, pmPopup.Controls.Count + 1,
"Batch Property", "Encapsulate these fields");
batchPropertyCmdEvent = _applicationObject.Events.get_
CommandBarEvents(batchPropertyCmd) as CommandBarEvents;
batchPropertyCmdEvent.Click += new _dispCommandBarControlEvents_
ClickEventHandler(BatchPropertyCmdEvent_Click);
CommandBarButton convertToAutoPropCmd = helper.
AddButtonToPopup(pmPopup, pmPopup.Controls.Count + 1,
"Convert to Auto-Property", "Convert to Auto-Property(C# 3.0 style)");
convertToAutoPropCmdEvent = _applicationObject.Events.get_
CommandBarEvents(convertToAutoPropCmd) as CommandBarEvents;
convertToAutoPropCmdEvent.Click += new _dispCommandBarControlEvents_
ClickEventHandler(ConvertToAutoPropCmdEvent_Click);
CommandBarButton convertToNormalPropCmd =
helper.AddButtonToPopup(pmPopup, pmPopup.Controls.Count + 1,
"Convert to Normal-Property", "Convert to Normal-Property
(C# 2.0 style)");
convertToNormalPropCmdEvent = _applicationObject.Events.get_
CommandBarEvents(convertToNormalPropCmd) as CommandBarEvents;
convertToNormalPropCmdEvent.Click += new _dispCommandBarControlEvents_
ClickEventHandler(ConvertToNormalPropCmdEvent_Click);
2)命令的实现
为简化问题,这里约定字段、自动属性和常规属性的声明格式为:
C# Code - 字段和属性约定格式
private int id;
string name;
private DateTime birth;
private int Id { get; set; }
public string Name { private get; set; }
public DateTime Birth { get; private set; }
public int Id
{
get { return id; }
set { id = value; }
}
public string Name
{
get { return name; }
set { name = value; }
}
public DateTime Birth
{
get { return birth; }
set { birth = value; }
}
字段采用camelCase风格命名,属性采用PascalCase风格命名。
在实现Batch Property时,可以采用正则表达式找出选中行中的多个字段,为它们一一生成属性,最后将属性代码放入剪贴板:
C# Code - 实现BatchProperty命令
private void BatchPropertyCmdEvent_Click(object CommandBarControl,
ref bool Handled, ref bool CancelDefault)
{
string selectedLines = helper.GetSelectedLines();
GenerateProperties(selectedLines);
}
private void GenerateProperties(string selectedLines)
{
Regex regex = new Regex(".*(?<type>\\b\\w+\\b)\\s+(?<fieldName>\\w+)(\\s*=.+)*;", RegexOptions.IgnoreCase);
MatchCollection fieldLines = regex.Matches(selectedLines);
// 约定字段为camelCase, 属性为PascalCase
StringBuilder props = new StringBuilder();
foreach (Match fieldLine in fieldLines)
{
string type = fieldLine.Groups["type"].Value;
string fieldName = fieldLine.Groups["fieldName"].Value;
bool readOnly = fieldLine.Value.IndexOf("readonly") >= 0;
props.AppendLine(GenerateNormalProperty
("public", type, fieldName, readOnly, false));
}
Clipboard.SetText(props.ToString());
}
private string GenerateNormalProperty
(string modifier, string type, string fieldName, bool readOnly, bool writeOnly)
{
string propertyName = StringHelper.GetPascalCaseString(fieldName);
// 添加一个换行可利用VS的自动格式特性
string format = "{0} {1} {2}{{ " + Environment.NewLine + "{3} {4} }}";
string getter = string.Empty;
if (!writeOnly)
{
getter = string.Format("get{{ return {0}; }}", fieldName);
}
string setter = string.Empty;
if (!readOnly)
{
setter = string.Format("set {{ {0} = value; }}", fieldName);
}
return string.Format(format, modifier, type, propertyName, getter, setter);
}
GetSelectedLines方法是获取当前文档中选中的代码行:
C# Code - 获取选中的文本行
public string GetSelectedLines()
{
TextSelection selectedText = dte.ActiveDocument.Selection as TextSelection;
TextPoint topPoint = selectedText.TopPoint;
EditPoint bottomPoint = selectedText.BottomPoint.CreateEditPoint();
return bottomPoint.GetLines(topPoint.Line, bottomPoint.Line + 1);
}
字段可能为readonly的,此时将只生成getter代码。这样在生成属性时考虑的主要因素为:字段类型、字段名称、是否只读。这样
C# Code
private int id;
string name;
private readonly DateTime birth;
会生成如下的代码(会拷贝到剪贴板中):
C# Code
public int Id
{
get { return id; }
set { id = value; }
}
public string Name
{
get { return name; }
set { name = value; }
}
public DateTime Birth
{
get { return birth; }
}
在实现Convert to Auto-Property时,思路与上面相同,也是将查找到的各个常规属性转换为自动属性:
C# Code - 实现Convert to Auto-Property命令
private void ConvertToAutoPropCmdEvent_Click(object CommandBarControl, ref bool Handled, ref bool CancelDefault)
{
string selectedLines = helper.GetSelectedLines();
Regex propRegex = new Regex(
"((?<modifier>\\b\\w+\\b)\\s+)*(?<type>\\b\\w+\\b)\\s+(?<name>\\w+)\\s*{(.|\\n)+?(?<!;\\s*)}",
RegexOptions.IgnoreCase | RegexOptions.Multiline);
MatchCollection properties = propRegex.Matches(selectedLines);
StringBuilder autoProps = new StringBuilder();
foreach (Match prop in properties)
{
string modifier = prop.Groups["modifier"].Value;
if (modifier.Length == 0)
{
modifier = "private";
}
string type = prop.Groups["type"].Value;
string name = prop.Groups["name"].Value;
string propText = prop.Value;
bool hasGetter = Regex.IsMatch(propText, "get\\s*{(.|\\n)+?}");
bool hasSetter = Regex.IsMatch(propText, "set\\s*{(.|\\n)+?}");
if (!hasGetter && !hasSetter) { break; }
autoProps.AppendLine(GenerateAutoProperty(modifier, type, name, hasGetter, hasSetter));
}
Clipboard.SetText(autoProps.ToString());
}
private string GenerateAutoProperty(string modifier, string type, string name, bool hasGetter, bool hasSetter)
{
string format = "{0} {1} {2}{{ {3} {4} }}";
string getter = "get;";
if (!hasGetter)
{
getter = "private " + getter;
}
string setter = "set;";
if (!hasSetter)
{
setter = "private " + setter;
}
return string.Format(format, modifier, type, name, getter, setter);
}
对于代码
public int Id
{
get { return id; }
set { id = value; }
}
public string Name
{
set { name = value; }
}
public DateTime Birth
{
get { return birth; }
}
生成的结果为:
public int Id { get; set; }
public string Name { private get; set; }
public DateTime Birth { get; private set; }
最后是Convert to Normal-Property:
C# Code - 实现Convert to Normal-Property命令
private void ConvertToNormalPropCmdEvent_Click(object CommandBarControl, ref bool Handled, ref bool CancelDefault)
{
string selectedLines = helper.GetSelectedLines();
Regex propRegex = new Regex(
"((?<modifier>\\w+)?\\s+)?(?<type>\\w+)\\s+(?<name>\\w+)\\s*{(.|\\n)*?get;(.|\\n)*?set;\\s*}",
RegexOptions.IgnoreCase | RegexOptions.Multiline);
MatchCollection autoProperties = propRegex.Matches(selectedLines);
StringBuilder normalProps = new StringBuilder();
foreach (Match prop in autoProperties)
{
string modifier = prop.Groups["modifier"].Value;
string type = prop.Groups["type"].Value;
string name = prop.Groups["name"].Value;
string propText = prop.Value;
bool writeOnly = Regex.IsMatch(propText, "private\\s+get;");
bool readOnly = Regex.IsMatch(propText, "private\\s+set;");
if (writeOnly && readOnly) { break; }
normalProps.AppendLine(GenerateNormalProperty(modifier, type, name, readOnly, writeOnly));
}
Clipboard.SetText(normalProps.ToString());
}
至此这三个命令就全部实现了,它们都是将结果放在剪切板中,因为我感觉很难确定出一个合适的位置。
可以从这里下载代码,也可以在这里下载可运行的Add-In(解压缩后将文件放在[My Documents Path]\Visual Studio 2008\Addins下)。
希望这个功能能让您对编辑器的扩展有更多的了解。
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