我看到了一些不同的方法来迭代C#中的字典。有标准的方法吗?


当前回答

除了在使用

foreach(KeyValuePair<string, string> entry in myDictionary)
{
    // do something with entry.Value or entry.Key
}

or

foreach(var entry in myDictionary)
{
    // do something with entry.Value or entry.Key
}

最完整的是以下内容,因为您可以从初始化中看到字典类型,kvp是KeyValuePair

var myDictionary = new Dictionary<string, string>(x);//fill dictionary with x

foreach(var kvp in myDictionary)//iterate over dictionary
{
    // do something with kvp.Value or kvp.Key
}

其他回答

根据MSDN上的官方文档,迭代字典的标准方法是:

foreach (DictionaryEntry entry in myDictionary)
{
     //Read entry.Key and entry.Value here
}

除了在使用

foreach(KeyValuePair<string, string> entry in myDictionary)
{
    // do something with entry.Value or entry.Key
}

or

foreach(var entry in myDictionary)
{
    // do something with entry.Value or entry.Key
}

最完整的是以下内容,因为您可以从初始化中看到字典类型,kvp是KeyValuePair

var myDictionary = new Dictionary<string, string>(x);//fill dictionary with x

foreach(var kvp in myDictionary)//iterate over dictionary
{
    // do something with kvp.Value or kvp.Key
}

在.NET Framework 4.7中,可以使用分解

var fruits = new Dictionary<string, int>();
...
foreach (var (fruit, number) in fruits)
{
    Console.WriteLine(fruit + ": " + number);
}

要使此代码在较低的C#版本上运行,请添加System.ValueTuple NuGet包并在某处编写

public static class MyExtensions
{
    public static void Deconstruct<T1, T2>(this KeyValuePair<T1, T2> tuple,
        out T1 key, out T2 value)
    {
        key = tuple.Key;
        value = tuple.Value;
    }
}

迭代字典的最简单形式:

foreach(var item in myDictionary)
{ 
    Console.WriteLine(item.Key);
    Console.WriteLine(item.Value);
}
foreach(KeyValuePair<string, string> entry in myDictionary)
{
    // do something with entry.Value or entry.Key
}