public ActionGenerationParameterBindContext(ActionGenerationContext context, ParameterInfo par)
: base(context)
{
this.ParameterInfo = par;
this.NullableChecker = new NullableTypes(par.ParameterType);
this.LocalExpression = Expression.Parameter(this.ParameterType,par.Name);
this.GetItemExpression = Expression.Call(this.ArgumentsExpression, ArgumentGetItemMethodInfo, Expression.Constant(par.Name));
}
public IAction Generate(MethodInfo method)
{
if (!method.IsPublic) return null;
//标记了NoAction的方法跳过
var noAction = method.GetCustomAttribute<NonActionAttribute>();
if (noAction != null) return null;
var buildContext = new ActionGenerationContext(method, this.BinderFactory);
return Generate(buildContext);
}
protected ActionGenerationContext(ActionGenerationContext context)
{
this.ActionMethodInfo = context.ActionMethodInfo;
this.ArgumentsExpression = context.ArgumentsExpression;
this.RequestExpression = context.RequestExpression;
this.ContextExpression = context.ContextExpression;
this.CodeExpressions = context.CodeExpressions;
this.LocalVarExpressions = context.LocalVarExpressions;
this.BinderFactory = context.BinderFactory;
}
/// <summary>
/// 根据上下文，生成一个Action
/// </summary>
/// <param name="cmdContext"></param>
/// <returns></returns>
IAction Generate(ActionGenerationContext cmdContext)
{
//获取所有参数
var parameters = cmdContext.ActionMethodInfo.GetParameters();
//函数调用的参数列表
var argExprs = new List<ParameterExpression>();
//循环所有参数
foreach (var par in parameters)
{
#region 生成为每个参数赋值的表达式
//构建参数上下文
var parContext = new ActionGenerationParameterBindContext(cmdContext,par);
//把参数变量添加到变量表中
cmdContext.LocalVarExpressions.Add(parContext.LocalExpression);
argExprs.Add(parContext.LocalExpression);
//生成绑定参数值的表达式
if (parContext.NullableChecker.IsNullable)
{
GenerateNullableBindCodes(parContext);
}
else {
GenerateNonullableBindCodes(parContext);
}
#endregion
}
#region 生成函数调用 controllerInstance.Insert(username,password);
var instanceExpr = cmdContext.ControllerInstanceExpression;
var instanceConvertExpr = Expression.Convert(instanceExpr,cmdContext.ActionMethodInfo.DeclaringType);
var callExpr = Expression.Call(instanceConvertExpr, cmdContext.ActionMethodInfo, argExprs);
cmdContext.CodeExpressions.Add(callExpr);
#endregion
//根据Action Method的不同返回值类型，生成不同的Action
return GenerateReturn(cmdContext,callExpr);
}
/// <summary>
/// 根据Action Method的不同返回值类型，生成不同的Action
/// </summary>
/// <param name="cmdContext"></param>
/// <param name="callExpr"></param>
/// <returns></returns>
IAction GenerateReturn(ActionGenerationContext cmdContext, MethodCallExpression callExpr)
{
var retType = cmdContext.ActionMethodInfo.ReturnType;
var labelTarget = Expression.Label(retType);
if (cmdContext.ActionMethodInfo.ReturnType.FullName.StartsWith("System.Task"))
{
}
else {
var retExpr = Expression.Return(labelTarget, callExpr);
LabelExpression labelExpr = Expression.Label(labelTarget);
cmdContext.CodeExpressions.Add(labelExpr);
Expression blockExpr = Expression.Block(cmdContext.LocalVarExpressions, cmdContext.CodeExpressions);
if (blockExpr.CanReduce) blockExpr.ReduceAndCheck();
if (cmdContext.ActionMethodInfo.ReturnType == typeof(void))
{
var lamda = Expression.Lambda<Action<object, IArguments, IRequest, Context>>(blockExpr, cmdContext.ControllerInstanceExpression, cmdContext.ArgumentsExpression, cmdContext.RequestExpression, cmdContext.ContextExpression);
var func = lamda.Compile();
return new NoresultSyncAction(cmdContext.ActionMethodInfo, func);
}
else {
var lamda = Expression.Lambda<Func<object, IArguments, IRequest, Context,object>>(blockExpr, cmdContext.ControllerInstanceExpression, cmdContext.ArgumentsExpression, cmdContext.RequestExpression, cmdContext.ContextExpression);
var func = lamda.Compile();
return new ResultSyncAction(cmdContext.ActionMethodInfo, func);
}
}
return null;
//var returnValueExpr = Expression.Convert(resultExpr, typeof(object));
}