/// <summary>
/// 创建字段的获取器委托。
/// </summary>
/// <param name="fieldInfo">字段元数据。</param>
/// <returns>字段获取器的委托。</returns>
public static DynamicMemberGetter CreateFieldGetter(this FieldInfo fieldInfo)
{
if (fieldInfo == null)
{
throw new ArgumentNullException(nameof(fieldInfo));
}
return(GetterCache.GetOrAdd(fieldInfo, m =>
{
var emit = new EmitHelper(DefineTypes.Object, new Type[] { DefineTypes.Object }, fieldInfo.DeclaringType);
if (fieldInfo.IsStatic)
{
emit.ldsfld(fieldInfo)
.end();
}
else
{
emit.ldarg_0
.castType(fieldInfo.DeclaringType)
.ldfld(fieldInfo)
.end();
}
emit.boxIfValueType(fieldInfo.FieldType)
.ret();
return emit.CreateDelegate <DynamicMemberGetter>();
}));
}
/// <summary>
/// 创建方法的调用委托。
/// </summary>
/// <param name="methodInfo">方法元数据。方法不能是一个尚未构造泛型参数的方法</param>
/// <returns>方法调用的委托。</returns>
public static DynamicMethodInvoker CreateMethodInvoker(this MethodInfo methodInfo)
{
if (methodInfo == null)
{
throw new ArgumentNullException(nameof(methodInfo));
}
if (methodInfo.IsGenericMethodDefinition)
{
throw new ArgumentException("不支持尚未构造泛型参数的方法。", nameof(methodInfo));
}
return(MethodCache.GetOrAdd(methodInfo, m =>
{
var declaringType = m.DeclaringType;
var emit = new EmitHelper(DefineTypes.Object, new Type[] { DefineTypes.Object, DefineTypes.ObjectArray }, declaringType);
var isStatic = m.IsStatic;
var returnType = m.ReturnType; //- 方法的返回类型
var parameterInfos = m.GetParameters(); //- 方法的参数集合
var parameterLength = parameterInfos.Length;
var parameterLocals = new LocalBuilder[parameterLength];
var hasByRef = false;
CreateParameterLocals(1, emit, parameterInfos, parameterLength, parameterLocals, ref hasByRef);
if (!isStatic)
{
emit.ldarg_0
.castType_any(declaringType)
.end();
}
LoadParameterLocals(emit, parameterInfos, parameterLength, parameterLocals);
emit.call(isStatic, m);
if (returnType == typeof(void))
{
emit.ldnull
.end();
}
else
{
emit.boxIfValueType(returnType)
.end();
}
if (hasByRef)
{
SaveParameters(1, emit, parameterInfos, parameterLength, parameterLocals);
}
emit.ret().end();
return emit.CreateDelegate <DynamicMethodInvoker>();
}));
}
/// <summary>
/// 创建属性的获取器委托。
/// </summary>
/// <param name="propertyInfo">属性元数据。</param>
/// <returns>属性获取器的委托。</returns>
public static DynamicMemberGetter CreatePropertyGetter(this PropertyInfo propertyInfo)
{
if (propertyInfo == null)
{
throw new ArgumentNullException(nameof(propertyInfo));
}
return(GetterCache.GetOrAdd(propertyInfo, m =>
{
var declaringType = propertyInfo.DeclaringType;
var methodInfo = propertyInfo.GetGetMethod(true);
if (methodInfo == null)
{
return null;
}
var emit = new EmitHelper(DefineTypes.Object, new Type[] { DefineTypes.Object }, declaringType);
var isStatic = methodInfo.IsStatic;
if (!isStatic)
{
emit.ldarg_0
.castType(declaringType)
.callvirt(methodInfo)
.end();
}
else
{
emit.call(methodInfo)
.end();
}
emit.boxIfValueType(propertyInfo.PropertyType)
.ret();
return emit.CreateDelegate <DynamicMemberGetter>();
}));
}
