C# Type.GetConstructors()用法及代码示例

Type.GetConstructors() 方法用于获取 Type 对象的构造函数。该方法的重载列表中有2个方法如下：

Type.GetConstructors() Method

此方法用于返回为当前 Type 定义的所有公共构造函数。
用法:

public System.Reflection.ConstructorInfo[] GetConstructors ();

返回值：该方法返回 ConstructorInfo 数组对象，表示为当前 Type 定义的所有公共实例构造函数，但不包括类型初始化器(静态构造函数)。以下示例程序旨在说明 Type.GetConstructors() 方法的使用：示例 1：

C#


// C# program to demonstrate the
// Type.GetConstructors() Method
using System;
using System.Globalization;
using System.Reflection;
class GFG {
    // Main Method
    public static void Main()
    {
        // Declaring and initializing object
        object obj = new Object();
        // Getting the type of object
        // using GetType() method
        Type type = obj.GetType();
        // Getting constructors of the current Type.
        // using GetArrayRank() Method
        ConstructorInfo[] info = type.GetConstructors();
        // Display all the public instance constructors
        Console.WriteLine("All constructors are shown below");
        for (int i = 0; i < info.Length; i++)
            Console.WriteLine(info[i]);
    }
}

输出：

All constructors are shown below
Void .ctor()

范例2：

C#


// C# program to demonstrate the
// Type.GetConstructors() Method
using System;
using System.Globalization;
using System.Reflection;
class GFG {
    // Main Method
    public static void Main()
    {
        // Declaring and initializing Type object
        Type type = typeof(string);
        // Getting constructors of the current Type.
        // using GetConstructors() Method
        ConstructorInfo[] info = type.GetConstructors();
        // Display all the public instance constructors
        Console.WriteLine("All constructors are shown below");
        for (int i = 0; i < info.Length; i++)
            Console.WriteLine(info[i]);
    }
}

输出：

All constructors are shown below
Void .ctor(Char[])
Void .ctor(Char[], Int32, Int32)
Void .ctor(Char*)
Void .ctor(Char*, Int32, Int32)
Void .ctor(SByte*)
Void .ctor(SByte*, Int32, Int32)
Void .ctor(SByte*, Int32, Int32, Encoding)
Void .ctor(Char, Int32)
Void .ctor(ReadOnlySpan`1)

Type.GetConstructors(BindingFlags) Method

此方法用于返回为当前类型定义的构造函数，在派生类中重写时使用指定的 BindingFlags，
用法:

public abstract System.Reflection.ConstructorInfo[] GetConstructors (System.Reflection.BindingFlags bindingAttr);

在这里，它需要一个位掩码，该位掩码由一个或多个 BindingFlags 组成，指定在哪个点进行参加。或零，返回空值。
下面是一些 BindingFlags 过滤器标志，可用于定义要在搜索中包含哪些构造函数：

您必须指定 BindingFlags.Instance 或 BindingFlags.Static 才能获得返回。
指定 BindingFlags.Public 以在搜索中包含公共构造函数。
指定 BindingFlags.NonPublic 以在搜索中包括非公共构造函数(即私有、内部和受保护的构造函数)。不返回基类的构造函数。

返回值：此方法返回一个 ConstructorInfo 对象数组，表示为当前 Type 定义的与指定绑定约束匹配的所有构造函数，包括类型初始值设定项(如果已定义)。以下示例程序旨在说明上述方法的使用：示例 1：

C#


// C# program to demonstrate the
// Type.GetConstructors(BindingFlags)
// Method
using System;
using System.Globalization;
using System.Reflection;
class GFG {
    // Main Method
    public static void Main()
    {
        // Declaring and initializing Type object
        Type type = typeof(string);
        // Declaring and initializing BindingFlags
        // it is used to specify how the search
        // is conducted
        BindingFlags bf = BindingFlags.Public
                          | BindingFlags.Static
                          | BindingFlags.NonPublic
                          | BindingFlags.Instance;
        // Getting constructors of the current Type.
        // using GetConstructors() Method
        ConstructorInfo[] info = type.GetConstructors(bf);
        // Display all constructors
        Console.WriteLine("All constructors are shown below");
        for (int i = 0; i < info.Length; i++)
            Console.WriteLine(info[i]);
    }
}

输出：

All constructors are shown below
Void .ctor(Char[])
Void .ctor(Char[], Int32, Int32)
Void .ctor(Char*)
Void .ctor(Char*, Int32, Int32)
Void .ctor(SByte*)
Void .ctor(SByte*, Int32, Int32)
Void .ctor(SByte*, Int32, Int32, Encoding)
Void .ctor(Char, Int32)
Void .ctor(ReadOnlySpan`1)

范例2：

C#


// C# program to demonstrate the
// Type.GetConstructors(BindingFlags)
// Method
using System;
using System.Globalization;
using System.Reflection;
class GFG {
    // Main Method
    public static void Main()
    {
        // Creating and initializing object
        object obj = new Object();
        // Declaring and initializing Type object
        Type type = obj.GetType();
        // Declaring and initializing BindingFlags
        // it is used to specify how the search is conducted
        BindingFlags bf = BindingFlags.Public
                          | BindingFlags.Static
                          | BindingFlags.NonPublic
                          | BindingFlags.Instance;
        // Getting constructors of the current Type.
        // using GetConstructors() Method
        ConstructorInfo[] info = type.GetConstructors(bf);
        // Display all constructors
        Console.WriteLine("All constructors are shown below");
        for (int i = 0; i < info.Length; i++)
            Console.WriteLine(info[i]);
    }
}

输出：

All constructors are shown below
Void .ctor()

参考：

https://docs.microsoft.com/en-us/dotnet/api/system.type.getconstructors?view=netcore-3.0

相关用法

注：本文由纯净天空筛选整理自RohitPrasad3大神的英文原创作品 Type.GetConstructors() Method in C# with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。