您可以使用以下代码为您的解决方案:-

public void Linq94() 
{ 
    int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 }; 
    int[] numbersB = { 1, 3, 5, 7, 8 }; 

    var allNumbers = numbersA.Concat(numbersB); 

    Console.WriteLine("All numbers from both arrays:"); 
    foreach (var n in allNumbers) 
    { 
        Console.WriteLine(n); 
    } 
}

// The answer that I was looking for when searching
public void Answer()
{
    IEnumerable<YourClass> first = this.GetFirstIEnumerableList();
    // Assign to empty list so we can use later
    IEnumerable<YourClass> second = new List<YourClass>();

    if (IwantToUseSecondList)
    {
        second = this.GetSecondIEnumerableList();  
    }
    IEnumerable<SchemapassgruppData> concatedList = first.Concat(second);
}

您可以使用以下代码为您的解决方案:-

public void Linq94() 
{ 
    int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 }; 
    int[] numbersB = { 1, 3, 5, 7, 8 }; 

    var allNumbers = numbersA.Concat(numbersB); 

    Console.WriteLine("All numbers from both arrays:"); 
    foreach (var n in allNumbers) 
    { 
        Console.WriteLine(n); 
    } 
}

是的，LINQ to Objects通过Enumerable支持这一点。合并多个数组:

var together = first.Concat(second);

注意:如果第一或第二是空的，你会收到一个ArgumentNullException。为了避免这种情况&像对待空集一样对待空值，可以像这样使用空合并操作符:

var together = (first ?? Enumerable.Empty<string>()).Concat(second ?? Enumerable.Empty<string>()); //amending `<string>` to the appropriate type

我知道这是一个相对较老的帖子，但如果你想连接多个IEnumerable，我使用以下方法

var joinedSel = new[] { first, second, third }.Where(x => x != null).SelectMany(x => x);

这消除了任何空IEnumerable，并允许多个连接。

基于craig1231的答案，我创建了一些扩展方法…

    public static IEnumerable<T> JoinLists<T>(this IEnumerable<T> list1, IEnumerable<T> list2)
    {
        var joined = new[] { list1, list2 }.Where(x => x != null).SelectMany(x => x);
        return joined ?? Enumerable.Empty<T>();
    }
    public static IEnumerable<T> JoinLists<T>(this IEnumerable<T> list1, IEnumerable<T> list2, IEnumerable<T> list3)
    {
        var joined = new[] { list1, list2, list3 }.Where(x => x != null).SelectMany(x => x);
        return joined ?? Enumerable.Empty<T>();
    }
    public static IEnumerable<T> JoinMany<T>(params IEnumerable<T>[] array)
    {
        var final = array.Where(x => x != null).SelectMany(x => x);
        return final ?? Enumerable.Empty<T>();
    }