Question

我试图从Web服务中获取列表的总和。

[WebMethod]
public string CalculateSum(List<int> listInt)
{
       int[] sum = listInt.ToArray();

        return sum; // error under sum on this line

}

但是我得到的错误无法将int转换为字符串，这应该有用吗？

客户代码：

    public partial class Form1 : Form
    {
        List<int> listInt = new List<int>();

        public Form1()
        {
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e)
        {

        }
        private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            listInt.Add(Convert.ToInt32(textBox1.Text));
            textBox1.Clear();
            listBox1.Items.Clear();
            for (int i = 0; i < listInt.Count; i++)
            {
                listBox1.Items.Add(listInt[i]);
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            CalculateSumOfList.ServiceReference1.Service1SoapClient client = new CalculateSumOfList.ServiceReference1.Service1SoapClient();
            CalculateSumOfList.ServiceReference1.ArrayOfInt arrayOfInt = new CalculateSumOfList.ServiceReference1.ArrayOfInt();
            arrayOfInt.AddRange(listInt);
            int result = client.CalculateSum(arrayOfInt); //here
            label1.Text = Convert.ToString(result);


        }



    }
}

我在client.CalculateSum(arrayOfInt);

时遇到错误

Answer 1

[WebMethod]
public int CalculateSum(List<int> listInt)
{
    int sum = listInt.Sum();
    return sum; // error under sum on this line

}

注意函数的返回值 - 你声明它返回一个字符串而不是一个整数。

Answer 2

您可以使用

 return sum.ToString();

或

return "" + sum;

但首先要考虑：一个总和int值的函数是否真的会返回一个字符串？它似乎更有意义作为int函数：

public int CalculateSum(List<int> listInt)
{
    int sum = listInt.Sum();
    return sum;  // now matches the return-type of the method 
}

webmethod int to list of list of sum

2 个答案: