Исходный код вики Сценарии

Редактировал(а) Alexandr Fokin 2025/05/13 13:04
Последние авторы
1 |(% style="width:394px" %)Компиляция дерева в делегат|(% style="width:1090px" %){{code language="c#"}}Expression
2 .Lambda(expressionValiarble)
3 .Compile();{{/code}}
4 |(% style="width:394px" %)[[Простое копирование свойств одного класса в другой>>doc:Разработка.NET.C#.Рантайм и типы.Expression tree | Деревья выражений.Сценарии.Простое копирование свойств одного класса в другой.WebHome]]|(% style="width:1090px" %)
5 |(% style="width:394px" %)[[Маппинг на основе выражения доступа к свойству>>doc:.Маппинг на основе выражения доступа к свойству.WebHome]]|(% style="width:1090px" %)
6 |(% style="width:394px" %)Вызов делегата при построении EpressionTree|(% style="width:1090px" %)Expression Trees and Invoking a Delegate
7 [[https:~~/~~/stackoverflow.com/questions/2215712/expression-trees-and-invoking-a-delegate>>url:https://stackoverflow.com/questions/2215712/expression-trees-and-invoking-a-delegate]]
8 |(% style="width:394px" %)Объявлений локальной переменной в блоке
9 (без передачи извне)|(% style="width:1090px" %)(((
10 переменная типа указана из области видимости, но не определена 
11 [[https:~~/~~/question-it.com/questions/717473/peremennaja-tipa-ukazana-iz-oblasti-vidimosti-no-ne-opredelena>>url:https://question-it.com/questions/717473/peremennaja-tipa-ukazana-iz-oblasti-vidimosti-no-ne-opredelena]]
12 )))
13 |(% style="width:394px" %) |(% style="width:1090px" %)(((
14 How do I set a field value in an C# Expression tree?
15 [[https:~~/~~/stackoverflow.com/questions/321650/how-do-i-set-a-field-value-in-an-c-sharp-expression-tree>>https://stackoverflow.com/questions/321650/how-do-i-set-a-field-value-in-an-c-sharp-expression-tree]]
16 )))
17 |(% style="width:394px" %)Типизированый вызов конструктора|(% style="width:1090px" %){{code language="c#"}}var constructorInfo = type.GetConstructors().First(e => e.Attributes.HasFlag(MethodAttributes.Public));
18 var constructorParameter1 = Expression.Parameter(typeof(bool));
19 var constructorExp = Expression.New(constructorInfo, constructorParameter1);
20
21 // Func<bool, object> or Func<bool, T>
22 var constructorDelegate = Expression
23 .Lambda<Func<bool, object>>(
24 constructorExp,
25 constructorParameter1
26 )
27 .Compile();{{/code}}(((
28 How do you call a constructor via an expression tree on an existing object?
29 [[https:~~/~~/stackoverflow.com/questions/16363838/how-do-you-call-a-constructor-via-an-expression-tree-on-an-existing-object>>https://stackoverflow.com/questions/16363838/how-do-you-call-a-constructor-via-an-expression-tree-on-an-existing-object]]
30 )))
31 |(% style="width:394px" %)Нетипизированый вызов|(% style="width:1090px" %)(((
32 |{{code language="c#"}}public delegate object ConstructorDelegate(object[]? Args);
33
34 public static ConstructorDelegate GetConstructorWithArgsDelegate(
35 ConstructorInfo constructorInfo)
36 {
37 ParameterExpression constructorParameters = Expression.Parameter(typeof(object?[]));
38
39 Expression[] parameterExpressions;
40 {
41 ParameterInfo[] parametersInfos = constructorInfo.GetParameters();
42 parameterExpressions = new Expression[parametersInfos.Length];
43
44 for (int i = 0; i < parametersInfos.Length; i++)
45 {
46 ConstantExpression ithIndex = Expression.Constant(i);
47 BinaryExpression ithParameter = Expression.ArrayIndex(
48 constructorParameters,
49 ithIndex);
50 UnaryExpression unboxedIthParameter = Expression.Convert(
51 ithParameter,
52 parametersInfos[i].ParameterType
53 );
54 parameterExpressions[i] = unboxedIthParameter;
55 }
56 }
57
58 NewExpression constructorCallExp = Expression.New(
59 constructorInfo,
60 parameterExpressions);
61
62 var convertResultExp = Expression.Convert(
63 constructorCallExp,
64 typeof(object)
65 );
66
67 var constructorHandler = Expression
68 .Lambda<ConstructorDelegate>(
69 convertResultExp,
70 constructorParameters
71 )
72 .Compile();
73
74 return constructorHandler;
75 }{{/code}}|{{code language="c#"}}object Func<object[]>{{/code}}(((
76 C# Expression tree: object array to Expression.New() parameters
77 [[https:~~/~~/stackoverflow.com/questions/67968927/c-sharp-expression-tree-object-array-to-expression-new-parameters>>https://stackoverflow.com/questions/67968927/c-sharp-expression-tree-object-array-to-expression-new-parameters]]
78 )))
79 |{{code language="c#"}}public delegate object? MethodDelegate(object instance, object[]? Args);
80
81 public static MethodDelegate GetMethodWithArgsDelegate(
82 MethodInfo methodInfo,
83 Type instanceType)
84 {
85 ParameterExpression instanceParameter = Expression.Parameter(typeof(object));
86 ParameterExpression methodParameters = Expression.Parameter(typeof(object?[]));
87
88 Expression instanceExp;
89 Expression[] parameterExpressions;
90 {
91 instanceExp = Expression.Convert(instanceParameter, instanceType);
92
93 ParameterInfo[] parametersInfos = methodInfo.GetParameters();
94 parameterExpressions = new Expression[parametersInfos.Length];
95
96 for (int i = 0; i < parametersInfos.Length; i++)
97 {
98 ConstantExpression ithIndex = Expression.Constant(i);
99 BinaryExpression ithParameter = Expression.ArrayIndex(
100 methodParameters,
101 ithIndex);
102 UnaryExpression unboxedIthParameter = Expression.Convert(
103 ithParameter,
104 parametersInfos[i].ParameterType
105 );
106 parameterExpressions[i] = unboxedIthParameter;
107 }
108 }
109
110 var callExpression = Expression.Call(
111 instanceExp,
112 methodInfo,
113 parameterExpressions
114 );
115
116 var convertResultExp = Expression.Convert(
117 callExpression,
118 typeof(object)
119 );
120
121 var callHandler = Expression
122 .Lambda<MethodDelegate>(
123 convertResultExp,
124 instanceParameter,
125 methodParameters
126 )
127 .Compile();
128
129 return callHandler;
130 }{{/code}}|{{code language="c#"}}object? Func<object, object[]>{{/code}}
131
132
133 )))
134 |(% style="width:394px" %)[[Generic enum to int>>doc:.Generic enum to int.WebHome]]|(% style="width:1090px" %)
135
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