初始化C ++ / CLI结构数组

问题描述

我希望部分初始化结构数组，例如C ++ POD类型。 String ^通常是char *，但是托管C ++不允许这样做。

#include "stdafx.h"

using namespace System;

ref struct Field
{
    String^ name;
    int fences;
    int length;
};

int main(array<System::String ^> ^args)
{
    array<Field^>^ farm =
    {
        { "eenie",10 },{ "meenie",20 },{ "miny",4 }
    };

    for each (Field^ field in farm)
    {
        field->length = field->fences * 22;
    }

    return 0;
}

这导致

1>arrayinit.cpp(18): error C2440: 'initializing' : cannot convert from 'const char [6]' to 'Field ^'
1>          Reason: cannot convert from 'const char *' to 'Field ^'
1>          No user-defined-conversion operator available,or
1>          Cannot convert an unmanaged type to a managed type

所以我尝试了

#include "stdafx.h"

using namespace System;

ref struct Field
{
    String^ name;
    int fences;
    int length;
};

int main(array<System::String ^> ^args)
{
    array<Field^>^ farm =
    {
        { String("eenie"),{ String("meenie"),{ String("miny"),4 }
    };

    for each (Field^ field in farm)
    {
        field->length = field->fences * 22;
    }

    return 0;
}

现在我得到

1>arrayinit.cpp(18): error C2440: 'initializing' : cannot convert from 'System::String' to 'Field ^'
1>          No user-defined-conversion operator available,or
1>          No user-defined-conversion operator available that can perform this conversion,or the operator cannot be called
1>arrayinit.cpp(18): error C2078: too many initializers

我看过的几乎每个示例都仅说明了如何初始化字符串或整数数组。我还没有找到初始化包含字符串的结构数组的方法。

是否有一种简单的方法？还是必须创建一个特殊的构造函数并gcnew每个元素？

解决方法

我发现我可以使用特殊的构造函数gcnew每个元素。有没有一种类似于POD初始化的简单方法？

constructor(props){
    super(props);
    this.state = {
      loading: true
    };
   //....

    this.tempoRealeDestro = [];
    this.tempoRealeSinistro = [];
}

dataReceived(){
    this.dimensioneArrayRaggiunta = this.props.dimensioneArrayRaggiunta;
     if(this.checkContatore == false){
       this.contatoreDestro = this.props.contatoreTimestampDestro;
       this.contatoreSinistro = this.props.contatoreTimestampSinistro;
       this.checkContatore = true;
     }
 this.stopClick();
}

或者，如果将Field更改为值而不是引用，

#include "stdafx.h"

using namespace System;

ref struct Field
{
    String^ name;
    int fences;
    int length;

    Field(String^ x,int in_fences)
    {
        name = x;
        fences = in_fences;
    }
};

int main(array<System::String ^> ^args)
{
    array<Field^>^ farm =
    {
        gcnew Field("eenie",10 ),gcnew Field("meenie",20 ),gcnew Field("miny",4 )
    };

    for each (Field^ field in farm)
    {
        field->length = field->fences * 22;
    }

    return 0;
}

这比对每个字段进行更新要好一些。