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Редактировал(а) Alexandr Fokin 2025/05/13 13:04
От версии 2.4
отредактировано Alexandr Fokin
на 2023/05/31 09:57
на 2023/05/31 09:57
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К версии 2.12
отредактировано Alexandr Fokin
на 2025/05/13 13:04
на 2025/05/13 13:04
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... ... @@ -13,14 +13,8 @@ 13 13 |(% style="width:394px" %) |(% style="width:1090px" %)((( 14 14 How do I set a field value in an C# Expression tree? 15 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 -How do you call a constructor via an expression tree on an existing object? 18 -[[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]] 19 - 20 -How do I set a field value in an C# Expression tree? 21 -[[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]] 22 22 ))) 23 -|(% style="width:394px" %) Вызов конструктора|(% style="width:1090px" %){{code language="c#"}}var constructorInfo = t.GetConstructors().First(e => e.Attributes.HasFlag(MethodAttributes.Public));17 +|(% style="width:394px" %)Типизированый вызов конструктора|(% style="width:1090px" %){{code language="c#"}}var constructorInfo = type.GetConstructors().First(e => e.Attributes.HasFlag(MethodAttributes.Public)); 24 24 var constructorParameter1 = Expression.Parameter(typeof(bool)); 25 25 var constructorExp = Expression.New(constructorInfo, constructorParameter1); 26 26 ... ... @@ -28,26 +28,119 @@ 28 28 var constructorDelegate = Expression 29 29 .Lambda<Func<bool, object>>( 30 30 constructorExp, 31 - deletedParameter25 + constructorParameter1 32 32 ) 33 33 .Compile();{{/code}}((( 34 34 How do you call a constructor via an expression tree on an existing object? 35 35 [[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]] 36 36 ))) 31 +|(% style="width:394px" %)Нетипизированый вызов|(% style="width:1090px" %)((( 32 +|{{code language="c#"}}public delegate object ConstructorDelegate(object[]? Args); 37 37 38 -==== ==== 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); 39 39 40 -==== ==== 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}} 41 41 132 + 133 +))) 134 +|(% style="width:394px" %)[[Generic enum to int>>doc:.Generic enum to int.WebHome]]|(% style="width:1090px" %) 135 + 42 42 ==== ==== 43 43 44 - 45 ----- 46 - 47 47 ==== ==== 48 48 49 - 50 ----- 51 - 52 - 53 ----- 140 +==== ====