本文整理汇总了C#中Expression.AddFirst方法的典型用法代码示例。如果您正苦于以下问题：C# Expression.AddFirst方法的具体用法？C# Expression.AddFirst怎么用？C# Expression.AddFirst使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类Expression的用法示例。
在下文中一共展示了Expression.AddFirst方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C#代码示例。
示例1: CallMethodNoResult
/// <summary>
/// Helper method for generating a MetaObject which calls a
/// specific method on Dynamic, but uses one of the arguments for
/// the result.
/// </summary>
private DynamicMetaObject CallMethodNoResult(string methodName, DynamicMetaObjectBinder binder, Expression[] args, Fallback fallback) {
//
// First, call fallback to do default binding
// This produces either an error or a call to a .NET member
//
DynamicMetaObject fallbackResult = fallback(null);
//
// Build a new expression like:
// if (TryDeleteMember(payload)) { } else { fallbackResult }
//
var callDynamic = new DynamicMetaObject(
Expression.Condition(
Expression.Call(
GetLimitedSelf(),
typeof(DynamicObject).GetMethod(methodName),
args.AddFirst(Constant(binder))
),
Expression.Empty(),
fallbackResult.Expression,
typeof(void)
),
GetRestrictions().Merge(fallbackResult.Restrictions)
);
//
// Now, call fallback again using our new MO as the error
// When we do this, one of two things can happen:
// 1. Binding will succeed, and it will ignore our call to
// the dynamic method, OR
// 2. Binding will fail, and it will use the MO we created
// above.
//
return fallback(callDynamic);
}示例2: CallMethodReturnLast
/// <summary>
/// Helper method for generating a MetaObject which calls a
/// specific method on Dynamic, but uses one of the arguments for
/// the result.
/// </summary>
private DynamicMetaObject CallMethodReturnLast(string methodName, DynamicMetaObjectBinder binder, Expression[] args, Fallback fallback) {
//
// First, call fallback to do default binding
// This produces either an error or a call to a .NET member
//
DynamicMetaObject fallbackResult = fallback(null);
//
// Build a new expression like:
// {
// object result;
// TrySetMember(payload, result = value) ? result : fallbackResult
// }
//
var result = Expression.Parameter(typeof(object), null);
var callArgs = args.AddFirst(Constant(binder));
callArgs[args.Length] = Expression.Assign(result, callArgs[args.Length]);
var callDynamic = new DynamicMetaObject(
Expression.Block(
new[] { result },
Expression.Condition(
Expression.Call(
GetLimitedSelf(),
typeof(DynamicObject).GetMethod(methodName),
callArgs
),
result,
fallbackResult.Expression,
typeof(object)
)
),
GetRestrictions().Merge(fallbackResult.Restrictions)
);
//
// Now, call fallback again using our new MO as the error
// When we do this, one of two things can happen:
// 1. Binding will succeed, and it will ignore our call to
// the dynamic method, OR
// 2. Binding will fail, and it will use the MO we created
// above.
//
return fallback(callDynamic);
}