DirectiveProcessor.ProcessDirective 方法

项目
10/25/2012

在派生类中重写时，根据模板文件处理单个指令。

命名空间： Microsoft.VisualStudio.TextTemplating
程序集： Microsoft.VisualStudio.TextTemplating.11.0（在 Microsoft.VisualStudio.TextTemplating.11.0.dll 中）

语法

声明
Public MustOverride Sub ProcessDirective ( _
    directiveName As String, _
    arguments As IDictionary(Of String, String) _
)

public abstract void ProcessDirective(
    string directiveName,
    IDictionary<string, string> arguments
)

public:
virtual void ProcessDirective(
    String^ directiveName, 
    IDictionary<String^, String^>^ arguments
) abstract

abstract ProcessDirective : 
        directiveName:string * 
        arguments:IDictionary<string, string> -> unit

public abstract function ProcessDirective(
    directiveName : String, 
    arguments : IDictionary<String, String>
)

参数

directiveName
类型：System.String
要处理的指令的名称。

arguments
类型：System.Collections.Generic.IDictionary<String, String>
指令的参数。

实现

IDirectiveProcessor.ProcessDirective(String, IDictionary<String, String>)

备注

一个指令处理器可以支持许多不同的指令。在调用 ProcessDirective 时，条件语句仅运行所调用的特定指令。

该指令处理参数并生成要添加到生成的转换类的代码。

示例

下面的代码示例演示自定义指令处理器的可能实现。此代码示例摘自为 DirectiveProcessor 类提供的一个更大的示例。

public override void ProcessDirective(string directiveName, IDictionary<string, string> arguments)
{
    if (string.Compare(directiveName, "CoolDirective", StringComparison.OrdinalIgnoreCase) == 0)
    {
        string fileName;

        if (!arguments.TryGetValue("FileName", out fileName))
        {
            throw new DirectiveProcessorException("Required argument 'FileName' not specified.");
        }

        if (string.IsNullOrEmpty(fileName))
        {
            throw new DirectiveProcessorException("Argument 'FileName' is null or empty.");
        }

        //Now we add code to the generated transformation class.
        //This directive supports either Visual Basic or C#, so we must use the
        //System.CodeDom to create the code.
        //If a directive supports only one language, you can hard code the code.
        //--------------------------------------------------------------------------
        
        CodeMemberField documentField = new CodeMemberField();

        documentField.Name = "document" + directiveCount + "Value";
        documentField.Type = new CodeTypeReference(typeof(XmlDocument));
        documentField.Attributes = MemberAttributes.Private;

        CodeMemberProperty documentProperty = new CodeMemberProperty();

        documentProperty.Name = "Document" + directiveCount;
        documentProperty.Type = new CodeTypeReference(typeof(XmlDocument));
        documentProperty.Attributes = MemberAttributes.Public;
        documentProperty.HasSet = false;
        documentProperty.HasGet = true;

        CodeExpression fieldName = new CodeFieldReferenceExpression(new CodeThisReferenceExpression(), documentField.Name);
        CodeExpression booleanTest = new CodeBinaryOperatorExpression(fieldName, CodeBinaryOperatorType.IdentityEquality, new CodePrimitiveExpression(null));
        CodeExpression rightSide = new CodeMethodInvokeExpression(new CodeTypeReferenceExpression("XmlReaderHelper"), "ReadXml", new CodePrimitiveExpression(fileName));
        CodeStatement[] thenSteps = new CodeStatement[] { new CodeAssignStatement(fieldName, rightSide) };

        CodeConditionStatement ifThen = new CodeConditionStatement(booleanTest, thenSteps);
        documentProperty.GetStatements.Add(ifThen);

        CodeStatement s = new CodeMethodReturnStatement(fieldName);
        documentProperty.GetStatements.Add(s);

        CodeGeneratorOptions options = new CodeGeneratorOptions();
        options.BlankLinesBetweenMembers = true;
        options.IndentString = "    ";
        options.VerbatimOrder = true;
        options.BracingStyle = "C";

        using (StringWriter writer = new StringWriter(codeBuffer, CultureInfo.InvariantCulture))
        {
            codeDomProvider.GenerateCodeFromMember(documentField, writer, options);
            codeDomProvider.GenerateCodeFromMember(documentProperty, writer, options);
        }

    }//end CoolDirective


    //One directive processor can contain many directives.
    //If you want to support more directives, the code goes here...
    //-----------------------------------------------------------------
    if (string.Compare(directiveName, "supercooldirective", StringComparison.OrdinalIgnoreCase) == 0)
    {
        //code for SuperCoolDirective goes here...
    }//end SuperCoolDirective


    //Track how many times the processor has been called.
    //-----------------------------------------------------------------
    directiveCount++;

}//end ProcessDirective

Public Overrides Sub ProcessDirective(ByVal directiveName As String, ByVal arguments As IDictionary(Of String, String))

    If String.Compare(directiveName, "CoolDirective", StringComparison.OrdinalIgnoreCase) = 0 Then

        Dim fileName As String

        If Not (arguments.TryGetValue("FileName", fileName)) Then
            Throw New DirectiveProcessorException("Required argument 'FileName' not specified.")
        End If

        If String.IsNullOrEmpty(fileName) Then
            Throw New DirectiveProcessorException("Argument 'FileName' is null or empty.")
        End If

        'Now we add code to the generated transformation class.
        'This directive supports either Visual Basic or C#, so we must use the
        'System.CodeDom to create the code.
        'If a directive supports only one language, you can hard code the code.
        '--------------------------------------------------------------------------

        Dim documentField As CodeMemberField = New CodeMemberField()

        documentField.Name = "document" & directiveCount & "Value"
        documentField.Type = New CodeTypeReference(GetType(XmlDocument))
        documentField.Attributes = MemberAttributes.Private

        Dim documentProperty As CodeMemberProperty = New CodeMemberProperty()

        documentProperty.Name = "Document" & directiveCount
        documentProperty.Type = New CodeTypeReference(GetType(XmlDocument))
        documentProperty.Attributes = MemberAttributes.Public
        documentProperty.HasSet = False
        documentProperty.HasGet = True

        Dim fieldName As CodeExpression = New CodeFieldReferenceExpression(New CodeThisReferenceExpression(), documentField.Name)
        Dim booleanTest As CodeExpression = New CodeBinaryOperatorExpression(fieldName, CodeBinaryOperatorType.IdentityEquality, New CodePrimitiveExpression(Nothing))
        Dim rightSide As CodeExpression = New CodeMethodInvokeExpression(New CodeTypeReferenceExpression("XmlReaderHelper"), "ReadXml", New CodePrimitiveExpression(fileName))
        Dim thenSteps As CodeStatement() = New CodeStatement() {New CodeAssignStatement(fieldName, rightSide)}

        Dim ifThen As CodeConditionStatement = New CodeConditionStatement(booleanTest, thenSteps)
        documentProperty.GetStatements.Add(ifThen)

        Dim s As CodeStatement = New CodeMethodReturnStatement(fieldName)
        documentProperty.GetStatements.Add(s)

        Dim options As CodeGeneratorOptions = New CodeGeneratorOptions()
        options.BlankLinesBetweenMembers = True
        options.IndentString = "    "
        options.VerbatimOrder = True
        options.BracingStyle = "VB"

        Using writer As StringWriter = New StringWriter(codeBuffer, CultureInfo.InvariantCulture)

            codeDomProvider.GenerateCodeFromMember(documentField, writer, options)
            codeDomProvider.GenerateCodeFromMember(documentProperty, writer, options)
        End Using

    End If  'CoolDirective


    'One directive processor can contain many directives.
    'If you want to support more directives, the code goes here...
    '-----------------------------------------------------------------
    If String.Compare(directiveName, "supercooldirective", StringComparison.OrdinalIgnoreCase) = 0 Then

        'code for SuperCoolDirective goes here
    End If 'SuperCoolDirective

    'Track how many times the processor has been called.
    '-----------------------------------------------------------------
    directiveCount += 1
End Sub 'ProcessDirective