private ValueGenerateBase CreateGenerate(GeneratedValueBaseAttribute attr, EGeneratedPurpose purpose, ValueGenerateBase source)
{
if (source == null && (attr.GeneratedPurpose & purpose) == purpose)
{
switch (attr.GeneratedOption)
{
case EGeneratedOption.Ignore: return(IgnoreValueGenerate);
case EGeneratedOption.Identity: return(new ValueGenerateIdentity());
case EGeneratedOption.Database: return(new ValueGenerateDatabase());
case EGeneratedOption.Memory:
var memoryAttr = (GeneratedMemoryValueAttribute)attr;
return(new ValueGenerateMemory(memoryAttr.GeneratorType));
case EGeneratedOption.Expression:
var expAttr = (GeneratedExpressionAttribute)attr;
return(new ValueGenerateExpression(expAttr.Expression));
}
}
return(source);
}
/// <summary>
/// 创建表达式生成值特性。
/// </summary>
/// <param name="purpose">生成时的目的。</param>
public GeneratedExpressionAttribute(EGeneratedPurpose purpose)
: base(purpose)
{
}
/// <summary>
/// 创建生成值特性。
/// </summary>
/// <param name="purpose">生成值的目的。</param>
public GeneratedValueBaseAttribute(EGeneratedPurpose purpose)
{
GeneratedPurpose = purpose;
}
/// <summary>
/// 创建内存中生成值特性。
/// </summary>
/// <param name="generatorType">生成器类型，该类型必须实现<see cref="IMemoryValueGenerator"/>接口。</param>
/// <param name="purpose">生成目的。</param>
public GeneratedMemoryValueAttribute(Type generatorType, EGeneratedPurpose purpose = EGeneratedPurpose.Insert)
: base(purpose)
{
GeneratorType = generatorType;
}
/// <summary>
/// 创建数据库生成值特性。
/// </summary>
/// <param name="purpose">生成目的。</param>
public GeneratedValueAttribute(EGeneratedPurpose purpose = EGeneratedPurpose.Insert)
: base(purpose)
{
}
/// <summary>
/// 创建忽略值生成特性。
/// </summary>
/// <param name="purpose">生成时的目的。</param>
public GeneratedIgnoreAttribute(EGeneratedPurpose purpose)
: base(purpose)
{
}
public GeneratedGuidAttribute(EGeneratedPurpose purpose = EGeneratedPurpose.Insert)
: base(purpose)
{
Expression = Expression.Call(null, typeof(Guid).GetMethod(nameof(Guid.NewGuid)));
}
/// <summary>
/// 创建序列生成特性。
/// </summary>
/// <param name="name">序列名。</param>
/// <param name="purpose">生成目的。</param>
public SequenceAttribute(string name, EGeneratedPurpose purpose = EGeneratedPurpose.Insert)
: base(purpose)
{
Name = name;
}
public GeneratedDateTimeAttribute(EGeneratedPurpose purpose = EGeneratedPurpose.Update)
: base(purpose)
{
Expression = Expression.MakeMemberAccess(null, typeof(DateTime).GetProperty(nameof(DateTime.Now)));
}