public MSILWriter(MethodBase method, ILGenerator ilGenerator)
{
var parameters = method.GetParameters();
_methodHeader = new MethodHeader
{
Attributes = method.CallingConvention,
DeclaringType = method.DeclaringType,
ParameterTypes = method.GetParameters()
.Select <ParameterInfo, Type>(p => p.ParameterType)
.ToArray <Type>(),
ReturnType = typeof(void)
};
_parameters = new SimpleParameter[parameters.Length];
int positionOffset = method.IsStatic ? 0 : 1;
for (int i = 0; i < parameters.Length; ++i)
{
_parameters[i] = new SimpleParameter(
this,
parameters[i].Position + positionOffset,
parameters[i].ParameterType,
null);
}
_ilGenerator = ilGenerator;
}
/// <summary>
/// 初始化一个 <see cref="MethodGenerator"/> 类的实例.
/// </summary>
/// <param name="writer">指令写入器</param>
private MethodGenerator(ICILWriter writer)
{
if (writer == null)
{
throw new ArgumentNullException("writer");
}
var header = writer.MethodHeader;
//检查非静态方法是否传入了声明类型
if (header.DeclaringType == null && NotStaticMethod(header))
{
throw new ArgumentException("必须为非静态方法定义一个声明类型（方法所在类的类型）");
}
//检查参数是否有null
for (int i = 0; i < header.ParameterTypes.Length; ++i)
{
if (header.ParameterTypes[i] == null)
{
throw new ArgumentException("writer.Header.Parameters 不能包含null值", "writer");
}
}
_writer = writer;
_header = header;
//收集参数
_parameters = LazyIndexer.Init <int, Parameter>(parameterIndex =>
{
if (NotStaticMethod(_header))
{
++parameterIndex; //如果不是静态方法，那么将参数索引值+1，因为第0个参数是this(也就是对象本身)
}
return(new Parameter(this, _writer.GetParameter(parameterIndex)));
});
_currentScope = new Scope(this); //创建代码范围
}
/// <summary>
/// 判断不是静态方法
/// </summary>
/// <param name="header"></param>
/// <returns>true:不是静态方法,false:是静态方法</returns>
private static bool NotStaticMethod(MethodHeader header)
{
return((header.Attributes & CallingConventions.HasThis) == CallingConventions.HasThis);
}