c# - 在 C# 中从已排序的字典中获取数据时出错

Question

我有一个 SortedDictionary<Package, List<string>> .以下是包类:

using System;

namespace GetPackageInfo
{

public class Package : IComparable, IEquatable<Package> 
{
    public string PackageName;
    public string Version;

    public Package()
    {

    }

    public Package(string packageName)
    {
        this.PackageName = packageName;
    }

    public override int GetHashCode()
    {
        unchecked
        {
            int result = 17;
            result = result * 23 + ((PackageName != null) ? this.PackageName.GetHashCode() : 0);
            result = result * 23 + ((Version != null) ? this.Version.GetHashCode() : 0);
            return result;
        }
    }

    public bool Equals(Package other)
    {
        if (ReferenceEquals(null, other))
        {
            return false;
        }
        if (ReferenceEquals(this, other))
        {
            return true;
        }
        return Equals(this.PackageName, other.PackageName) &&
               Equals(this.Version, other.Version);
    }

    public override bool Equals(object obj)
    {
        Package temp = obj as Package;
        if (temp == null)
            return false;
        return this.Equals(temp);
    }

    public override string ToString()
    {
        return string.Format("PackageName: {0}, Version: {1}", PackageName, Version);
    }

    public int CompareTo(object obj)
    {
        if (obj == null)
            return 1;

        if (obj != null) 
            return (Equals(obj) ? -1 : 1);
        else
            throw new ArgumentException("Object is not a Temperature");
    }

每当我做 Contains或 ContainsKey在 SortedDictionary 上，即使名称和版本相同，它也不起作用。

if (nugetPackagesInfo.Keys.Any(p => p.Equals(package)))
{
    //List<string> currPackage;
    //nugetPackagesInfo.TryGetValue(package, out currPackage);
    if (!nugetPackagesInfo[package].Contains(packageFile))
    {
        nugetPackagesInfo[package].Add(packageFile);
    }

nuGetPackagesInfo是我的字典对象。 Any虽然返回真。但是一旦通过并到达nugetPackagesInfo[package] , 然后它抛出 KeyNotFoundException .你能帮我弄清楚吗？是我的CompareTo不正确？

Answer 1

CompareTo 的实现似乎不正确。事实上，您没有实现包的任何排序。您很可能应该按名称订购包，如果相同则按版本订购。

Package.CompareTo 的核心应该如下所示(简化；不考虑 other == null):

// try name ordering
int nameOrdering = this.Name.CompareTo(other.Name);

// names not equal ⇒ ordering is clear and no need to inspect further
if (nameOrdering != 0)
{
    return nameOrdering;
}
// names are equal ⇒ resort to version ordering    
else
{
    return this.Version.CompareTo(other.Version);
}

你还应该 read the documentation for String.CompareTo()因为它具有特定于文化的语义。