非静态字段，方法或属性需要对象引用

Question

using System;
using System.IO;
using System.Data;
using System.Text;
using System.Drawing;
using System.Data.OleDb;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Drawing.Printing;
using System.Collections.Generic;

namespace Eagle_Eye_Class_Finder
{

    public class GetSchedule
    {
        public GetSchedule()
        {
            IDnumber[] IDnumbers = new IDnumber[3];
            IDnumbers[0] = new IDnumber() { Name = "Joshua Banks", ID = "900456317", year = "Senior", class1 = "TEET 4090", class2 = "TEET 3020", class3 = "TEET 3090", class4 = "TEET 4290" };
            IDnumbers[1] = new IDnumber() { Name = "Sean Ward", ID = "900456318", year = "Junior", class1 = "ENGNR 4090", class2 = "ENGNR 3020", class3 = "ENGNR 3090", class4 = "ENGNR 4290" };
            IDnumbers[2] = new IDnumber() { Name = "Terrell Johnson", ID = "900456319", year = "Sophomore", class1 = "BUS 4090", class2 = "BUS 3020", class3 = "BUS 3090", class4 = "BUS 4290" };

        }
        public class IDnumber
        {
            public string Name { get; set; }
            public string ID { get; set; }
            public string year { get; set; }
            public string class1 { get; set; }
            public string class2 { get; set; }
            public string class3 { get; set; }
            public string class4 { get; set; }


           public static void ProcessNumber(IDnumber myNum)
                {
                    StringBuilder myData = new StringBuilder();
                    myData.AppendLine(IDnumber.Name);   
                    myData.AppendLine(": ");   
                    myData.AppendLine(IDnumber.ID);   
                    myData.AppendLine(IDnumber.year);   
                    myData.AppendLine(IDnumber.class1);   
                    myData.AppendLine(IDnumber.class2);   
                    myData.AppendLine(IDnumber.class3);   
                    myData.AppendLine(IDnumber.class4);  
                    MessageBox.Show(myData);
                }

            public string GetDataFromNumber(string ID)
            {

               foreach (IDnumber idCandidateMatch in IDnumbers)  

            { 

            if (IDCandidateMatch.ID == ID)
                {
                     StringBuilder myData = new StringBuilder();
                     myData.AppendLine(IDnumber.Name);   
                     myData.AppendLine(": ");   
                     myData.AppendLine(IDnumber.ID);   
                     myData.AppendLine(IDnumber.year);   
                     myData.AppendLine(IDnumber.class1);   
                     myData.AppendLine(IDnumber.class2);   
                     myData.AppendLine(IDnumber.class3);   
                     myData.AppendLine(IDnumber.class4);  
                     return myData;
        }
    }
    return "";
}
        }

    }
}using System;
using System.IO;
using System.Data;
using System.Text;
using System.Drawing;
using System.Data.OleDb;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Drawing.Printing;
using System.Collections.Generic;

namespace Eagle_Eye_Class_Finder
{

    public class GetSchedule
    {
        public GetSchedule()
        {
            IDnumber[] IDnumbers = new IDnumber[3];
            IDnumbers[0] = new IDnumber() { Name = "Joshua Banks", ID = "900456317", year = "Senior", class1 = "TEET 4090", class2 = "TEET 3020", class3 = "TEET 3090", class4 = "TEET 4290" };
            IDnumbers[1] = new IDnumber() { Name = "Sean Ward", ID = "900456318", year = "Junior", class1 = "ENGNR 4090", class2 = "ENGNR 3020", class3 = "ENGNR 3090", class4 = "ENGNR 4290" };
            IDnumbers[2] = new IDnumber() { Name = "Terrell Johnson", ID = "900456319", year = "Sophomore", class1 = "BUS 4090", class2 = "BUS 3020", class3 = "BUS 3090", class4 = "BUS 4290" };

        }
        public class IDnumber
        {
            public string Name { get; set; }
            public string ID { get; set; }
            public string year { get; set; }
            public string class1 { get; set; }
            public string class2 { get; set; }
            public string class3 { get; set; }
            public string class4 { get; set; }


           public static void ProcessNumber(IDnumber myNum)
                {
                    StringBuilder myData = new StringBuilder();
                    myData.AppendLine(IDnumber.Name);   
                    myData.AppendLine(": ");   
                    myData.AppendLine(IDnumber.ID);   
                    myData.AppendLine(IDnumber.year);   
                    myData.AppendLine(IDnumber.class1);// i get it for all of these   
                    myData.AppendLine(IDnumber.class2);   
                    myData.AppendLine(IDnumber.class3);   
                    myData.AppendLine(IDnumber.class4);  
                    MessageBox.Show(myData);
                }

            public string GetDataFromNumber(string ID)
            {

               foreach (IDnumber idCandidateMatch in IDnumbers)  

            { 

            if (IDCandidateMatch.ID == ID)
                {
                     StringBuilder myData = new StringBuilder();
                     myData.AppendLine(IDnumber.Name);   
                     myData.AppendLine(": ");   
                     myData.AppendLine(IDnumber.ID);   
                     myData.AppendLine(IDnumber.year);   
                     myData.AppendLine(IDnumber.class1);   
                     myData.AppendLine(IDnumber.class2);   
                     myData.AppendLine(IDnumber.class3);   
                     myData.AppendLine(IDnumber.class4);  
                     return myData;
        }
    }
    return "";
}
        }

    }
}

Answer 1

静态方法不应该引用自身，它应该引用你传递给它的IDnumber，如下所示：

public static void ProcessNumber(IDnumber myNum)
{
    StringBuilder myData = new StringBuilder();
    myData.AppendLine(myNum.Name);
    myData.AppendLine(": ");
    myData.AppendLine(myNum.ID);
    myData.AppendLine(myNum.year);
    myData.AppendLine(myNum.class1);// i get it for all of these   
    myData.AppendLine(myNum.class2);
    myData.AppendLine(myNum.class3);
    myData.AppendLine(myNum.class4);
    MessageBox.Show(myData.ToString());
}

Answer 2

好了很多代码，但这是一个例子

public class IDnumber 
    { 
        public string Name { get; set; } 
        public string ID { get; set; } 
        public string year { get; set; } 
        public string class1 { get; set; } 
        public string class2 { get; set; } 
        public string class3 { get; set; } 
        public string class4 { get; set; } 


       public static void ProcessNumber(IDnumber myNum) 
            { 
                StringBuilder myData = new StringBuilder(); 
                myData.AppendLine(IDnumber.Name);    
                myData.AppendLine(": ");    
                myData.AppendLine(IDnumber.ID);    
                myData.AppendLine(IDnumber.year);    
                myData.AppendLine(IDnumber.class1);// i get it for all of these    
                myData.AppendLine(IDnumber.class2);    
                myData.AppendLine(IDnumber.class3);    
                myData.AppendLine(IDnumber.class4);   
                MessageBox.Show(myData); 
            } 

你的方法是静态的，但是包含你所引用的成员的类不是，它不会那样工作，因为该方法永远不属于某个实例。

Answer 3

 public static void ProcessNumber(IDnumber myNum)
 {
                    StringBuilder myData = new StringBuilder();
                    myData.AppendLine(myNum.Name);   
                    myData.AppendLine(": ");   
                    myData.AppendLine(myNum.ID);   
                    myData.AppendLine(myNum.year);   
                    myData.AppendLine(myNum.class1);   
                    myData.AppendLine(myNum.class2);   
                    myData.AppendLine(myNum.class3);   
                    myData.AppendLine(myNum.class4);  
                    MessageBox.Show(myData);
 }

Answer 4

一种解决方案是：

        foreach (IDnumber idCandidateMatch in IDnumbers)  

        { 

        if (idCandidateMatch.ID == ID)
            {
                 StringBuilder myData = new StringBuilder();
                 myData.AppendLine(idCandidateMatch.Name);   
                 myData.AppendLine(": ");   
                 myData.AppendLine(idCandidateMatch.ID);   
                 myData.AppendLine(idCandidateMatch.year);   
                 myData.AppendLine(idCandidateMatch.class1);   
                 myData.AppendLine(idCandidateMatch.class2);   
                 myData.AppendLine(idCandidateMatch.class3);   
                 myData.AppendLine(idCandidateMatch.class4);  
                 return myData;
    }

而不是：

       foreach (IDnumber idCandidateMatch in IDnumbers)  

        { 

        if (IDCandidateMatch.ID == ID)
            {
                 StringBuilder myData = new StringBuilder();
                 myData.AppendLine(IDnumber.Name);   
                 myData.AppendLine(": ");   
                 myData.AppendLine(IDnumber.ID);   
                 myData.AppendLine(IDnumber.year);   
                 myData.AppendLine(IDnumber.class1);   
                 myData.AppendLine(IDnumber.class2);   
                 myData.AppendLine(IDnumber.class3);   
                 myData.AppendLine(IDnumber.class4);  
                 return myData;
    }
}
return "";

因为Name（和其他属性）不是静态的。

问题出在以下几行：

的ID号。[属性]

例如

IDnumber.ID

或

IDnumber.Name

因为ID，Name ......和其他不是静态的。解决方案是将类名替换为所有相关行中的实例变量：

像

idCandidateMatch.ID

idCandidateMatch.Name

... （见上面的代码）

请注意，您在此处使用不同的变量名称大小写：

        foreach (IDnumber *idCandidateMatch* in IDnumbers)  

在这里：

        if (*IDCandidateMatch*.ID == ID)

C＃是区分大小写的，不应该工作（除非我在源代码中遗漏了一些东西:)。