问题：
嘿伙计们，我有一个奇怪的问题，开始真的让我感到沮丧。我已经搜索了高低的答案，并尝试了很多不同的东西，但由于某种原因，我无法使这段代码正常工作。我使用反射来根据 T 的类型将匿名对象数组转换为特定类型。现在提到它之前，是反射是我正在做的事情的唯一方法（将脚本语言转换为Type Strong C＃对象）。
我的问题在第35-43行。如果值类型是List {T}的值，那么我首先检查它是否为空...如果是，我使用Activator.CreateInstance（）创建一个新列表（第58行），否则使用现有列表。我在这里面临的问题是，当调用此方法时，值总是为NULL，即使我在第43行设置了值。这意味着列表中的列表永远不会超过1个，即使我添加更多比1项...
在第23和51行，您可以看到我为其他类型设置了值，并且它运行正常，所以我在第34-43行上做错了什么阻止了这段代码正常工作？
守则：
您可以使用pastebin或以下的行号查看此代码：
public class ObjectProperty<T> : ObjectPropertyBase
{
/// <summary>
/// Gets or Sets the value for this property
/// </summary>
public T Value;
/// <summary>
/// Takes an array of string values, and converts it to the proper value type for
/// this instance's Generic Type
/// </summary>
/// <param name="ValueParams">The string value's to convert, and set the
/// Value of this instance to.
/// </param>
public override void SetValueFromParams(String[] ValueParams)
{
Type PropertyType = typeof(T);
// Check for array's, as they are handled differently
if (PropertyType.IsArray)
{
// Set the value to the instanced object
Value = (T)ConvertArray(ValueParams, PropertyType);
}
else if (PropertyType.IsGenericType)
{
// Grab our types interfaces and generic types
Type[] interfaces = PropertyType.GetInterfaces();
Type[] types = PropertyType.GetGenericArguments();
// Check for List<T>
if (interfaces.Any(i => i == typeof(IList)))
{
// Grab our current list... if the Value isnt created yet, make it
dynamic obj = (dynamic)Value ?? CreateList(types);
// Add our value to the list
if (types[0].IsArray)
obj.Add(ConvertArray(ValueParams, types[0]));
else
obj.Add(ConvertValue<dynamic>(ValueParams[0], types[0]));
Value = (T)obj;
}
else
throw new Exception($"Invalid Generic Type found \"{PropertyType}\"");
}
else
{
// Since we are not an array, extract our only value
Value = ConvertValue<T>(ValueParams[0], PropertyType);
}
}
protected static IList CreateList(Type[] genericTypes)
{
Type obj = typeof(List<>).MakeGenericType(genericTypes);
return (IList)Activator.CreateInstance(obj);
}
/// <summary>
/// Converts the object value into the Typed variant of this <see cref="Value"/>
/// </summary>
protected K ConvertValue<K>(object Value, Type PropertyType)
{
// No need to change type if types match
if (Value.GetType() == PropertyType)
return (K)Value;
// Enums need special care
if (PropertyType.IsEnum)
return (K)Enum.Parse(PropertyType, Value.ToString(), true);
return (K)Convert.ChangeType(Value, PropertyType);
}
/// <summary>
/// Converts the object array values into the Typed variant of this <see cref="Value"/>
/// </summary>
protected object ConvertArray(Object[] values, Type propertyType)
{
// Set the value to the instanced object
switch (propertyType.Name.ToLowerInvariant())
{
case "int[]":
case "int32[]":
return Array.ConvertAll(values, Convert.ToInt32);
case "string[]":
return Array.ConvertAll(values, Convert.ToString);
case "double[]":
return Array.ConvertAll(values, Convert.ToDouble);
default:
throw new Exception("Invalid property type: " + propertyType.Name);
}
}
}
感谢您查看我的问题，希望有人可以帮我解决这个问题。
编辑：调用方法
public class Example
{
[PropertyName("isExample")]
public ObjectProperty<bool> IsExample;
// .....
public void Parse(string[] Params)
{
// Fetch our property that we are setting the value to
FieldInfo prop = this.GetType().GetField("isExample");
// Create our instance, and parse
ObjectPropertyBase obj = ObjectPropertyBase.Create(prop);
obj.SetValueFromParams(Params);
prop.SetValue(this, obj);
}
}
// Base Class
public abstract class ObjectPropertyBase
{
/// <summary>
/// Takes an array of string values, and converts it to the proper value type for
/// this instance's Generic Type
/// </summary>
/// <param name="ValueParams">The string value's to convert, and set the
/// Value of this instance to.
/// </param>
public abstract void SetValueFromParams(String[] value);
/// <summary>
/// Using reflection, this method creates a new instance of the <paramref name="field"/>
/// type, and returns it.
/// </summary>
/// <remarks>
/// This method does NOT set the field value, since hey... we dont have an instance to work on
/// </remarks>
/// <param name="field">The field we are creating an instance for. </param>
/// <exception cref="System.Exception">
/// Thrown if the Field provided does not contain the <see cref="PropertyName"/> attribute
/// </exception>
public static ObjectPropertyBase Create(FieldInfo field)
{
// If the Custom attribute exists, we add it to the Mapping
Attribute attribute = Attribute.GetCustomAttribute(field, typeof(PropertyName));
if (attribute == null)
throw new Exception($"Internal property \"{field.Name}\" does not contain a PropertyName attribute!");
// Get our constructor
PropertyName fieldAttr = attribute as PropertyName;
return (ObjectPropertyBase)Activator.CreateInstance(
field.FieldType,
new object[] { }
);
}
}
示例：
答案 0 :(得分：0)
我弄清楚我做错了什么..我的反射代码没有任何问题，而是调用＆＃34; SetValueFromParams＆＃34;方法。在用新实例覆盖它之前，我首先检查C＃对象的ObjectProperty字段是否为空（以及新的List）。
修复：
public void Parse(string[] Params)
{
// Fetch our property that we are setting the value to
FieldInfo prop = this.GetType().GetField("IsExample");
ObjectPropertyBase obj;
// Get the value that is set
var value = prop.Value.GetValue(this);
// If the value is null, then we create a new object property instance
if (value == null)
obj = ObjectPropertyBase.Create(prop.Value);
else
obj = (ObjectPropertyBase)value;
// Set Values
obj.SetValueFromParams(Params);
prop.SetValue(this, obj);
}
感谢所有花时间看我问题的人！