Question

下面是我正在处理的代码的一部分，执行时出现以下错误。

“无法将类型void隐式转换为字符串”。

我该如何解决？

private static void Main(string[] args)
{
    string[] strArray = new string[n];
    int i = 0;

    foreach (example)
    {
        if (condition 1)
        {
            strArray[i] = output;
        }
        if (condition 2)
        {
            strArray[i] = output;
        }
        if (condition 3)
        {
            strArray[i] = output;
        }
        i = i + 1;
    }
}

Answer 1

当我向您展示代码

private static void Main(string[] args)
{
    string[] strArray = new string[n];
    int i = 0;

    foreach (example)
    {
        if (condition 1)
        {
            strArray[i] = output;
        }
        if (condition 2)
        {
            strArray[i] = output;
        }
        if (condition 3)
        {
            strArray[i] = output;
        }
        i = i + 1;
    }
}

进入.net小提琴，我得到：

Compilation error (line 1, col 16): Expected class, delegate, enum, interface, or struct
Compilation error (line 1, col 33): Identifier expected
Compilation error (line 1, col 35): Expected class, delegate, enum, interface, or struct
Compilation error (line 3, col 12): Identifier expected
Compilation error (line 3, col 14): Expected class, delegate, enum, interface, or struct
Compilation error (line 3, col 29): Expected class, delegate, enum, interface, or struct
Compilation error (line 3, col 38): Expected class, delegate, enum, interface, or struct
Compilation error (line 10, col 25): Expected class, delegate, enum, interface, or struct
Compilation error (line 11, col 9): Type or namespace definition, or end-of-file expected

用

环绕

public class MyClass
{
    // your code
}

让我离开

Compilation error (line 8, col 21): Identifier expected
Compilation error (line 8, col 22): ) expected
Compilation error (line 10, col 23): ) expected
Compilation error (line 10, col 24): ; expected
Compilation error (line 10, col 24): Invalid expression term ')'
Compilation error (line 10, col 25): ; expected
Compilation error (line 14, col 23): ) expected
Compilation error (line 14, col 24): ; expected
Compilation error (line 14, col 24): Invalid expression term ')'
Compilation error (line 14, col 25): ; expected
Compilation error (line 18, col 23): ) expected
Compilation error (line 18, col 24): ; expected
Compilation error (line 18, col 24): Invalid expression term ')'
Compilation error (line 18, col 25): ; expected

将丢失的n和foreach固定到

string[] strArray = new string[10];
int i = 0;

var data = new [] {"1","2","3","4"};
foreach (var example in data)
{
     // your inner code
}

让我离开

Compilation error (line 11, col 23): ) expected
Compilation error (line 11, col 24): ; expected
Compilation error (line 11, col 24): Invalid expression term ')'
Compilation error (line 11, col 25): ; expected
Compilation error (line 15, col 23): ) expected
Compilation error (line 15, col 24): ; expected
Compilation error (line 15, col 24): Invalid expression term ')'
Compilation error (line 15, col 25): ; expected
Compilation error (line 19, col 23): ) expected
Compilation error (line 19, col 24): ; expected
Compilation error (line 19, col 24): Invalid expression term ')'
Compilation error (line 19, col 25): ; expected

修正内部条件

    if (i==1)
    {
        strArray[i] = "There is";
    }
    if (i==2)
    {
        strArray[i] = "is no";
    }
    if (i==3)
    {
        strArray[i] = "no spoon.";
    }
    i = i + 1;

导致缺少公共静态Main，而导致

的修复

public class MyClass
{
    public static void Main(string[] args)
    {
        string[] strArray = new string[10];
        int i = 0;
        var data = new[]{"1", "2", "3", "4"};
        foreach (var example in data)
        {
            if (i == 1)
            {
                strArray[i] = "There is";
            }

            if (i == 2)
            {
                strArray[i] = "is no";
            }

            if (i == 3)
            {
                strArray[i] = "no spoon.";
            }

            i = i + 1;
        }
    }
}

运行无错误的程序。

在旅途中的任何地方都没有弹出您的错误消息。

Answer 2

如果 output 是具有void返回类型的函数，则不能将其值分配给strArray [i]。在每种情况下，请确保函数的返回值都不为空。

此外，问题可能出在使用 foreach ，因此将其替换为for 循环，因为更改 foreach 的枚举数可能会产生一个问题。

Answer 3

尝试删除string[] args内的空白类型或Main(string[] args)

（不是其他解决方案）（但必须解决），但必须改进的地方

if(condtion==1){...}
if(condtion==2){...}
if(condtion==3){...}

等

更好的做法是将其替换为Switch，这样程序每次调用方法时都不会检查很多ifs

克服每个循环的空错误

3 个答案: