Question

所以我创建了一个包含字符串，整数和浮点数的类。

然后我在这些类型的main中声明了一个数组，并将该类型的对象读入其中

现在我需要在该数组中搜索特定值，如果该值匹配，则返回整个对象

我将如何做到这一点？

真的很难过

public class cdClass
{
    private static string artist = null;
    private static string genre = null;
    private static string cdTitle = null;
    private static float mSRP;
    private static int stock;
    private static int upc = 0;

    //Following functions are public member methods
    public void read_cd(string artist, string genre, string cdTitle, float mSRP, int stock, int upc)
    {
        //cdClass cd = null ;
        System.Console.WriteLine("Enter Artist Name: ");
        artist = Console.ReadLine();

        System.Console.WriteLine("Enter CD Title: ");
        cdTitle = Console.ReadLine();

        System.Console.WriteLine("Enter Genre Type: ");
        genre = Console.ReadLine();

        System.Console.WriteLine("Enter Manufacturers Suggested Retal Price: ");
        mSRP = float.Parse(Console.ReadLine());

        System.Console.WriteLine("Enter UPC Number: ");
        upc = int.Parse(Console.ReadLine());

        System.Console.WriteLine("Enter Stock: ");
        stock = int.Parse(Console.ReadLine());

        //return cd;
    }

    public  int get_upc()
    {
        return upc;
    }

MAIN：

//Follwoing cod will initialize an array of Cd's
cdClass[] cdArray = new cdClass[20];

float taxRate = 0;
do
{
    int i = 0;
    cdClass current_cd = new cdClass();
    current_cd.read_cd(artist, genre, cdTitle, mSRP, stock, upc);
    cdArray[i] = current_cd;
    i++;

} while (businesslogic.question() != 'Y');

buyer = inputfunctions.buyer();
int UPC = inputfunctions.get_upc();

for (int i = 0; i < 20; i++)
{
    if (cdArray[i].get_upc() == UPC)

Answer 1

您可以使用简单的LINQ扩展方法来搜索对象。

var foundItem = myArray.SingleOrDefault(item => item.intProperty == someValue);

以下是一些让您更熟悉的MSDN information regarding LINQ。

发布的代码

编辑。

我首先想说的是，你看起来像是从一个不同的语言带来了一些范例，比如使用你的getter方法而不是使用.NET样式属性的java，这是你可能想要研究的东西。但是我已经根据您的具体案例制作了一个代码示例..

您可以替换块

for (int i = 0; i < 20; i++)
{
    if (cdArray[i].get_upc() == UPC)

使用

cdClass foundCD = cdArray.SingleOrDefault(cd => cd.get_upc() == UPC);

或者使用BrokenGlass建议的Array.Find()方法..

cdClass foundCD = Array.Find(cdArray, delegate(cdClass cd) { return cd.get_upc() == UPC); });

Answer 2

在这种特殊情况下，

Array.Find()是LINQ的替代方案，特别是如果您只限于较旧的.NET版本：

var fooItem = Array.Find(myArray, item => item.fooProperty == "bar");

Answer 3

class TheThing {
    public int T1;
    public float T2;
}


List<TheThing> list = new List<TheThing>();

// Populate list...

var instance = (from thing in list
               where thing.T1 == 4
               select thing).SingleOrDefault();

这假设您只有一个匹配T1 == 4，如果您将拥有多个匹配，请执行以下操作：

var instances = from thing in list
                where thing.T1 == 4
                select thing;

Answer 4

使用LINQ，如：

public class Car
{
    public int ID { get; set; }
    public int CarName { get; set; }
}


class Program
{
    public IEnumerable<Car> GetCars
    {
        get { return MyDb.Cars; }
    }

    static void Main(string[] args)
    {
        Car myCar = GetCars.FirstOrDefault(x => x.ID == 5);
        Console.WriteLine("ID: {0} | CarName {1}", myCar.ID, myCar.CarName);
    }
}

http://msdn.microsoft.com/en-us/library/bb397926.aspx将为您提供必要的信息，帮助您开始使用LINQ。

Answer 5

对于那些仍然没有＆＃34;卡住＆＃34;在.Net 2 ...

我的类数组结构......

wsStudentID == 'somevalue'

我想根据使用List<EmployerContactDetailsClass> OrgList = new List<EmployerContactDetailsClass>();传递的索引值在此类中找到特定元素。

首先创建一个列表数组

EmployerContactDetailsClass OrgElem = new EmployerContactDetailsClass();

接下来创建一个节点元素

                        OrgElem.wsOrgID = reader["OrganisationID"].ToString();  //Org ID from database
                        OrgElem.wsContactID = reader["ContactID"].ToString();   //Contact ID from employer database
                        OrgElem.wsUserChoiceVerifier = (bool)reader["UserChoiceVerify"];  //boolean by default
                        if (reader["ContactGivenName"].ToString() != string.Empty && OrgElem.wsUserChoiceVerifier)
                            OrgElem.wsContactName = reader["ContactGivenName"].ToString() + " " + reader["ContactFamilyName"].ToString();
                        else
                            OrgElem.wsContactName = "TO WHOM IT MAY CONCERN";
                        OrgElem.wsContactEmail = reader["ContactEmail"].ToString();   //"support@tecnq.com.au";
                        OrgElem.wsEmployerEmail = reader["OrganisationEmail"].ToString();    //"support@tecnq.com.au";

                        //now add the elements into the array class
                        OrgList.Add(OrgElem);

从某些数据源构建列表（我的情况是Reader对象）

EmployerContactDetailsClass[] OrgListArray = (EmployerContactDetailsClass[])OrgList.ToArray();

转换列表＆lt;＆gt;进入一个数组[]

Delegate

使用String wsStudentID = 'FIND007'; //with respect to Roger Moore RIP EmployerContactDetailsClass OrgElemFound = Array.Find(OrgListArray, ByStudentID(wsStudentID));在数组中查找给定的StudentID。

//predicate method to return true or f if studentID matches the array list (used to pass into SendEmail)
private Predicate<EmployerContactDetailsClass> ByStudentID(string wsStudentID)
{
    return delegate(EmployerContactDetailsClass OrgElem)
    {
        return OrgElem.wsStudentID == wsStudentID;
    };
}

你的代码上的其他地方的Predicate方法......

function somefunc() {
    PageFrame.goToTab('test', function(item) {
        if(!item.search){

        return false;
        }
        //else do some stuff
    }, this);
}

window.onload = somefunc;

干杯！

c＃搜索特定int值的对象数组，然后返回该对象的所有数据

5 个答案: