c# - 在不知道字典名称的情况下从类中动态访问字典

Question

我有一个名为 SomeClass 的类。我里面几乎没有字典。

public class SomeClass
{
    public Dictionary<double, int[]> Dict1;
    public Dictionary<double, int[]> Dict2;
    public Dictionary<double, int[]> Dict3;
}

我在运行时知道字典名称。意味着我需要在哪个字典中分配数据只有在运行时才知道。我动态地在 string 中获取字典名称。有点像 -

String dictName = "Dict1"; //Achieved through some code mechanism in my project.

SomeClass DynValue = new SomeClass();
DynValue.[dictName/* Known at run time */].Add(3, new int[] { 5, 10 });

Answer 1

您应该在创建对象后初始化字典。

public class SomeClass
{
    public Dictionary<double, int[]> Dict1 = new Dictionary<double, int[]>();
    public Dictionary<double, int[]> Dict2 = new Dictionary<double, int[]>();
    public Dictionary<double, int[]> Dict3 = new Dictionary<double, int[]>();
}

要使用名称动态更改对象字段，您应该使用反射:

    String dictName = "Dict1"; //Achieved through some code mechanism in my project.

    SomeClass obj = new SomeClass();

    // Get dictionary interface object of 'Dict1' field using reflection
    var targetDict = obj.GetType().GetField(dictName).GetValue(obj) as IDictionary;

    // Add key and value to dictionary
    targetDict.Add(3.5d, new int[] { 5, 10 });

---

如果你需要使用反射初始化字典，你应该使用这个:

String dictName = "Dict1"; //Achieved through some code mechanism in my project.

SomeClass obj = new SomeClass();

// Get field info by name
var dictField = obj.GetType().GetField(dictName);

// Get dictionary interface object from field info using reflection
var targetDict = dictField.GetValue(obj) as IDictionary;
if (targetDict == null) // If field not initialized
{
    // Initialize field using default dictionary constructor
    targetDict = dictField.FieldType.GetConstructor(new Type[0]).Invoke(new object[0]) as IDictionary;

    // Set new dictionary instance to 'Dict1' field
    dictField.SetValue(obj, targetDict);
}

targetDict.Add(3.5d, new int[] { 5, 10 });