Question

我想遍历包含不同对象类型的ArrayList的ArrayList并将数据写入控制台。

我尝试使用IEnumerable和foreach循环。

//-------------------- Custom class Point --------------------
class Point
{
    public double X { get; set; }
    public double Y { get; set; }
    public double Z { get; set; }
    public Point(double x, double y, double z) { this.X = x; this.Y = y; this.Z = z; }
}
//-------------------- Main program --------------------
class Program
{
    static void Main(string[] args)
    {
        //ArrayList of different objects
        ArrayList arrlist = new ArrayList{
            new ArrayList { 1, "one" ,new Point(1.0,1.0,1.0)},
            new ArrayList { "two", 2,new Point(2.0,2.0,2.0) },
            new ArrayList { new Point(3.0,3.0,3.0), "three",3}
        };
        readData(arrlist);
        Console.ReadLine();
    }
    //-------------------- readData() function definition --------------------
    public static void readData(ArrayList arlst)
    {
        foreach (object obj in arlst)
        {
            foreach (object item in (IEnumerable)obj)
            {
                Console.WriteLine($"... {(IEnumerable)item.ToString()} ...");
            }
        }
    }
}

我希望将输入的每个项目的实际值写到ArrayList中。

编辑：格式化

Answer 1

这是您想要的输出吗？

... 1 ...
... one ...
... Point(1,1,1) ...
... two ...
... 2 ...
... Point(2,2,2) ...
... Point(3,3,3) ...
... three ...
... 3 ...

如果要打印点，则在Point类中需要这样的toString（）方法

override public string ToString() { return $"Point({X},{Y},{Z})"; }

Answer 2

//-------------------- Custom class Point --------------------
class Point
{
    public double X { get; set; }
    public double Y { get; set; }
    public double Z { get; set; }
    public Point(double x, double y, double z) { this.X = x; this.Y = y; this.Z = z; }
}
//-------------------- Main program --------------------
class Program
{
    static void Main(string[] args)
    {
        //ArrayList of different objects
        ArrayList arrlist = new ArrayList{
            new ArrayList { 1, "one" ,new Point(1.0,1.0,1.0)},
            new ArrayList { "two", 2,new Point(2.0,2.0,2.0) },
            new ArrayList { new Point(3.0,3.0,3.0), "three",3}
        };
        readData(arrlist);
        Console.ReadLine();
    }
    //-------------------- readData() function definition --------------------
    public static void readData(ArrayList arlst)
    {
        foreach (ArrayList l in arlst)
        {
            foreach (object item in l)
            {
                Console.WriteLine($"... {item.ToString()} ...");
            }
        }
    }
}

Answer 3

您可以将其用作数组列表以在数组列表上循环，有关示例，请参见注释：

public static void readData(ArrayList arlst)
{

    foreach (object l in arlst)
    {
        // try to convert it to arrayList to keep 
        var data = l as ArrayList;safe!
        if (data != null)
           // it is an arrayList, loop on it an print values
           foreach (object item in data)
               Console.WriteLine($"... {item.ToString()} ...");
        else
           // print the value if it is not an array list
           Console.WriteLine($"... {item.ToString()} ...");
    }
}

如何遍历和读取C＃中对象的ArrayLists的ArrayList中的值？

3 个答案: