Generator 类

2008-09-04

更新：2007 年 11 月

数据生成器的抽象基类。

命名空间： Microsoft.VisualStudio.TeamSystem.Data.DataGenerator
程序集： Microsoft.VisualStudio.TeamSystem.Data（在 Microsoft.VisualStudio.TeamSystem.Data.dll 中）

语法

声明
<GeneratorAttribute(GetType(DefaultGeneratorDesigner))> _
<CLSCompliantAttribute(True)> _
Public MustInherit Class Generator _
    Implements IGenerator, IDisposable
用法
Dim instance As Generator

[GeneratorAttribute(typeof(DefaultGeneratorDesigner))]
[CLSCompliantAttribute(true)]
public abstract class Generator : IGenerator, 
    IDisposable

[GeneratorAttribute(typeof(DefaultGeneratorDesigner))]
[CLSCompliantAttribute(true)]
public ref class Generator abstract : IGenerator, 
    IDisposable

public abstract class Generator implements IGenerator, IDisposable

备注

如果标准数据生成器不能满足需要，您可以创建自定义数据生成器。若要创建自定义数据生成器，必须创建一个实现 IGenerator 的类或从 Generator 继承的类。您可以通过使用 GeneratorAttribute 修饰该类来将其标识为数据生成器。

您可以为自定义数据生成器创建自定义设计器，也可以使用 DefaultGeneratorDesigner。

基类实现构造基于标记为 OutputAttribute 的公共属性的输出。输入是使用 InputAttribute 设置的。使用通过属性 (Attribute) 标记的属性 (Property) 可提供一个用于声明强类型输入和输出值的简单机制。

示例

标准数据生成器无法生成满足某些 CHECK 约束的数据。例如，如果某一 CHECK 约束要求日期位于两个不同范围中的一个范围内，则您无法使用标准 DateTime 生成器。此示例创建一个能够满足类似约束的自定义数据生成器。该生成器接受两个不同的范围作为其输入，并生成一个位于其中一个范围内的随机日期。有关更多信息，请参见演练：为 CHECK 约束创建自定义数据生成器。

using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.VisualStudio.TeamSystem.Data.DataGenerator;

namespace GeneratorDateRangesCS
{
    public class GeneratorDateRangesCS : Generator
    {
        DateTime mRange1Min;
        DateTime mRange1Max;

        DateTime mRange2Min;
        DateTime mRange2Max;

        [Input]
        public DateTime Range1Min
        {
            set {mRange1Min = value;}
        }

        [Input]
        public DateTime Range1Max
        {
            set {mRange1Max = value;}
        }

        [Input]
        public DateTime Range2Min
        {
            set {mRange2Min = value;}
        }

        [Input]
        public DateTime Range2Max
        {
            set {mRange2Max = value;}
        }


        DateTime mRandomDate;

        [Output]
        public DateTime RandomDate
        {
            get {return mRandomDate;}
        }


        Random mRandom;
        Random mRandomRange;

        protected override void OnInitialize(GeneratorInit initInfo)
        {
            mRandom = new Random(this.Seed);       //deterministic
            mRandomRange = new Random(this.Seed);  //deterministic

            //mRandom = new Random();                //non-deterministic
            //mRandomRange = new Random();           //non-deterministic

            base.OnInitialize(initInfo);
        }


        protected override void OnGenerateNextValues()
        {
            DateTime min;
            DateTime max;

            //Generate a random date from either range 1 or range 2.
            //Randomly select either range 1 or range 2 by randomly 
            //generating an odd or an even random number.
            //------------------------------------------------------------
            if (mRandomRange.Next() % 2 == 0)  //check for odd or even
            {
                min = mRange1Min;
                max = mRange1Max;
            }
            else
            {
                min = mRange2Min;
                max = mRange2Max;
            }

            //The formula for creating a random number in a specific range is:
            //start of range + (size of range * random number between 0 and 1)

            //size of range
            TimeSpan range = max - min;

            //(size of range * random number between 0 and 1)
            TimeSpan randomNumber = new TimeSpan((long)(range.Ticks * mRandom.NextDouble()));

            //start of range + (size of range * random number between 0 and 1)
            mRandomDate = min + randomNumber;
        }
    }//end class
}//end namespace

Imports Microsoft.VisualStudio.TeamSystem.Data.DataGenerator

Public Class GeneratorDateRangesVB
    Inherits Generator

    Dim mRange1Min As Date
    Dim mRange1Max As Date

    Dim mRange2Min As Date
    Dim mRange2Max As Date

    <Input()> _
    Public WriteOnly Property Range1Min() As Date
        Set(ByVal value As Date)
            mRange1Min = value
        End Set
    End Property

    <Input()> _
    Public WriteOnly Property Range1Max() As Date
        Set(ByVal value As Date)
            mRange1Max = value
        End Set
    End Property

    <Input()> _
    Public WriteOnly Property Range2Min() As Date
        Set(ByVal value As Date)
            mRange2Min = value
        End Set
    End Property

    <Input()> _
    Public WriteOnly Property Range2Max() As Date
        Set(ByVal value As Date)
            mRange2Max = value
        End Set
    End Property


    Dim mRandomDate As Date

    <Output()> _
    Public ReadOnly Property RandomDate() As Date
        Get
            Return mRandomDate
        End Get
    End Property


    Dim mRandom As Random
    Dim mRandomRange As Random

    Protected Overrides Sub OnInitialize(ByVal initInfo As GeneratorInit)

        mRandom = New Random(Me.Seed)       'deterministic
        mRandomRange = New Random(Me.Seed)  'deterministic

        'mRandom = New Random()              'non-deterministic
        'mRandomRange = New Random()         'non-deterministic

        MyBase.OnInitialize(initInfo)
    End Sub


    Protected Overrides Sub OnGenerateNextValues()

        Dim min As Date
        Dim max As Date

        'Generate a random date from either range 1 or range 2.
        'Randomly select either range 1 or range 2 by randomly 
        'generating an odd or an even random number.
        '------------------------------------------------------------
        If mRandomRange.Next() Mod 2 = 0 Then  'check for odd or even
            min = mRange1Min
            max = mRange1Max
        Else
            min = mRange2Min
            max = mRange2Max
        End If

        'The formula for creating a random number in a specific range is:
        'start of range + (size of range * random number between 0 and 1)

        'size of range
        Dim range As TimeSpan = max - min

        '(size of range * random number between 0 and 1)
        Dim randomNumber As TimeSpan = New TimeSpan(CLng(range.Ticks * mRandom.NextDouble()))

        'start of range + (size of range * random number between 0 and 1)
        mRandomDate = min + randomNumber

    End Sub
End Class

继承层次结构

线程安全

此类型的任何公共 static（在 Visual Basic 中为 Shared）成员都是线程安全的。但不保证所有实例成员都是线程安全的。

另请参见

参考

Generator 成员

Microsoft.VisualStudio.TeamSystem.Data.DataGenerator 命名空间

GeneratorAttribute

GeneratorInit

IGenerator

其他资源

创建自定义数据生成器

数据生成器扩展性概述

为列指定数据生成的详细信息