按值比较迭代类型（IEnumerables及其亲属）（以检查相等性）

Posted 2021-02-26

When I'm running unit tests, I find it very annoying to have to check equality within loops when I've got two collections of data. I know of no built-in way (let me know if there is one) [Edit: [CollectionAssert](http://msdn.microsoft.com/en-us/library/microsoft.visualstudio.testtools.unittesting.collectionassert.aspx) does it. Sometimes you need to turn your IEnumerables into arrays, though, using .ToArray()] to compare two collections' values (such as an array of bytes compared to a list of bytes), so I made this extension method to do it.

public static class Extensions
{
    static void Main()
	{
		var actual = new List<byte>();
		actual.AddRange(0x01, 0xFF);
		var expected = new byte[] {0x01, 0xFF};
		Assert.IsTrue(actual.Value.EqualsByValues(expected.Value));
	}
    /// <summary>
    /// Compare objects by their values.
    /// </summary>
    /// <param name="a"></param>
    /// <param name="b"></param>
    /// <returns></returns>
    public static bool EqualsByValues<T>(this IEnumerable<T> a, IEnumerable<T> b)
    {
        var aEnum = a.GetEnumerator();
        var bEnum = b.GetEnumerator();
        while (aEnum.MoveNext())
        {
            bEnum.MoveNext();
            if (!aEnum.Current.Equals(bEnum.Current))
            {
                return false;
            }
        }
        return true;
    }
}