C++ cli 如何从C++中的NoigIpUpDip中获取值？

我一直在为我的一个小项目试用windows窗体，该程序计算不同数量食物的含量

我认为数字统计是获取食物量信息的好方法

我尝试了以下Microsofts教程，介绍了如何从numericupdown中获取计算值，结果如下：

Double testVariable = numericSportfit.Value * 14.4; 
    


private: System::Void MyForm_Load(System::Object^ sender, System::EventArgs^ e) {
}

//Button Räkna
private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) 
{
    MessageBox::Show(testVariable.ToString(), "Resultat");
}

但是，我不断收到错误消息E0153表达式必须具有类类型，C2228在“.Value”的左边必须具有class/struct/union

我正在跑步。 我已经尝试搜索整个Web，关于如何获得C++的值，但我能找到的只有C.。 最初我只是想在C中编程，因为这是我最熟悉的，但是VS似乎只有C++和C. < 下面是整个代码块：

namespace Foderkalkylator {

using namespace System;
using namespace System::ComponentModel;
using namespace System::Collections;
using namespace System::Windows::Forms;
using namespace System::Data;
using namespace System::Drawing;

/// <summary>
/// Summary for MyForm
/// </summary>
public ref class MyForm : public System::Windows::Forms::Form
{
public:
    MyForm(void)
    {
        InitializeComponent();
        //
        //TODO: Add the constructor code here
        //
    }

protected:
    /// <summary>
    /// Clean up any resources being used.
    /// </summary>
    ~MyForm()
    {
        if (components)
        {
            delete components;
        }
    }
private: System::Windows::Forms::Button^ button1;
private: System::Windows::Forms::NumericUpDown^ numericSportfit;
protected:

private:
    /// <summary>
    /// Required designer variable.
    /// </summary>
    System::ComponentModel::Container ^components;


    /// <summary>
    /// Required method for Designer support - do not modify
    /// the contents of this method with the code editor.
    /// </summary>
    void InitializeComponent(void)
    {
        this->button1 = (gcnew System::Windows::Forms::Button());
        this->numericSportfit = (gcnew System::Windows::Forms::NumericUpDown());
        (cli::safe_cast<System::ComponentModel::ISupportInitialize^>(this->numericSportfit))->BeginInit();
        this->SuspendLayout();
        // 
        // button1
        // 
        this->button1->BackColor = System::Drawing::SystemColors::ActiveBorder;
        this->button1->Location = System::Drawing::Point(656, 387);
        this->button1->Name = L"button1";
        this->button1->Size = System::Drawing::Size(116, 62);
        this->button1->TabIndex = 0;
        this->button1->Text = L"Räkna";
        this->button1->UseVisualStyleBackColor = false;
        this->button1->Click += gcnew System::EventHandler(this, &MyForm::button1_Click);
        // 
        // numericSportfit
        // 
        this->numericSportfit->DecimalPlaces = 2;
        this->numericSportfit->Location = System::Drawing::Point(94, 55);
        this->numericSportfit->Name = L"numericSportfit";
        this->numericSportfit->Size = System::Drawing::Size(120, 20);
        this->numericSportfit->TabIndex = 1;
        this->numericSportfit->ValueChanged += gcnew System::EventHandler(this, &MyForm::numericSportfit_ValueChanged);
        // 
        // MyForm
        // 
        this->AutoScaleDimensions = System::Drawing::SizeF(6, 13);
        this->AutoScaleMode = System::Windows::Forms::AutoScaleMode::Font;
        this->ClientSize = System::Drawing::Size(784, 461);
        this->Controls->Add(this->numericSportfit);
        this->Controls->Add(this->button1);
        this->Name = L"MyForm";
        this->Text = L"Foderkalkylator";
        this->Load += gcnew System::EventHandler(this, &MyForm::MyForm_Load);
        (cli::safe_cast<System::ComponentModel::ISupportInitialize^>(this->numericSportfit))->EndInit();
        this->ResumeLayout(false);

    }

    
Double testVariable = numericSportfit.Value * 14.4; 
    


private: System::Void MyForm_Load(System::Object^ sender, System::EventArgs^ e) {
}

//Button Räkna
private: System::Void button1_Click(System::Object^ sender, System::EventArgs^ e) 
{
    MessageBox::Show(testVariable.ToString(), "Resultat");
}


//sportfit numericUpDown
private: System::Void numericSportfit_ValueChanged(System::Object^ sender, System::EventArgs^ e) 
{

}
};

}

---

提前谢谢

如果我理解正确，您的问题在于这一行：

double testVariable = numericSportfit.Value * 14.4; 

因此，请查看System:：Windows:：Forms:：NumericUpDown的联机帮助，给出一个显示以下内容的页面

public decimal Value { get; set; }

正如你所说的，只有C。我不记得那个调用的专有名称，但是它取代了C++中的GETValk和StValk等价物。所以我猜可能是getValue或您想要的Value

您应该能够深入到代码中并找到答案，而不是猜测。在您的源代码中，Control单击NumericUpDown，这将带您到定义对象的文件，您可能可以从中找到您需要的内容

另外-你可以在VS2019中编译C，我认为你需要将文件定义为.C文件，但老实说，如果你学习C，你会得到更好的应用程序，IMO

。Value应该是->Value