英文:
Restrict the type of a generic method on a class
问题
以下是翻译好的部分：
"I am currently working on a save system that will allow me to save data in Unity. I have a problem when it comes to the generic part. When the program wants to load a new element of type T, he will check if it exists then load it. If the element doesn't exist, a new element will be created using a constructor in the class T.
A problem happens when I tried to name the new element. I created a new class named Savable which will be parent for every data I will need to save, but I don't know how to restrict the type of the generic method so that T is considered as an element of type Savable, but the return object is of type T.
I currently tried to use the class T and to use a constructor with parameter, but it doesn't work.
Here is my current code."
"我目前正在开发一个保存系统，允许我在Unity中保存数据。在泛型部分出现了问题。当程序想要加载一个类型为T的新元素时，它会检查是否存在，然后加载它。如果元素不存在，将使用类T中的构造函数创建一个新元素。
当我尝试为新元素命名时出现问题。我创建了一个名为Savable的新类，它将成为我需要保存的每个数据的父类，但我不知道如何限制泛型方法的类型，以便T被视为Savable类型的元素，但返回对象的类型为T。
我目前尝试使用类T和带参数的构造函数，但它不起作用。
这是我的当前代码。"
"PS：对于我的英语，我很抱歉，这是我的第二语言。"
"The solution was found. I just needed to add the constraint Savable before the constraint new()."
"解决方案已找到。我只需要在new()约束之前添加Savable约束。"
英文:
I am currently working on a save system that will allow me to save data in Unity. I have a problem when it comes to the generic part. When the program wants to load a new element of type T, he will check if it exists then load it. If the element doesn't exist, a new element will be created using a constructor in the class T.
A problem happens when I tried to name the new element. I created a new class named Savable which will be parent for every data I will need to save, but I don't know how to restrict the type of the generic method so that T is considered as an element of type Savable, but the return object is of type T.
I currently tried to use the class T and to use a constructor with parameter, but it doesn't work.
Here is my current code.
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.IO;
public static class SaveManager
{
public static void SaveFromJson<T>(T data, string name, string path)
{
path = Application.persistentDataPath + path;
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
path = path + name + ".txt";
string json = JsonUtility.ToJson(data, true);
File.WriteAllText(path, json);
}
public static T LoadFromJson<T>(string name, string path) where T : new()
{
path = Application.persistentDataPath + path + name + ".txt";
Savable data = new T();
if (Directory.Exists(path))
{
string json = File.ReadAllText(path);
data = JsonUtility.FromJson<T>(json);
}
else
{
data.Name = name;
}
return data;
}
}
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Savable
{
public string Name;
}
PS : Sorry for my English, it is my second language.
The solution was found. I just needed to add the constraint Savable before the constraint new().
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.IO;
public static class SaveManager
{
public static void SaveFromJson<T>(T data, string name, string path)
{
path = Application.persistentDataPath + path;
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
path = path + name + ".txt";
string json = JsonUtility.ToJson(data, true);
File.WriteAllText(path, json);
}
public static T LoadFromJson<T>(string name, string path) where T : Savable, new()
{
path = Application.persistentDataPath + path + name + ".txt";
T data = new T();
if (Directory.Exists(path))
{
string json = File.ReadAllText(path);
data = JsonUtility.FromJson<T>(json);
}
else
{
data.Name = name;
}
return data;
}
}
答案1
得分: 0
解决方案已找到。我只需要在 new() 约束前添加 Savable 约束。
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.IO;
public static class SaveManager
{
public static void SaveFromJson<T>(T data, string name, string path)
{
path = Application.persistentDataPath + path;
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
path = path + name + ".txt";
string json = JsonUtility.ToJson(data, true);
File.WriteAllText(path, json);
}
public static T LoadFromJson<T>(string name, string path) where T : Savable, new()
{
path = Application.persistentDataPath + path + name + ".txt";
T data = new T();
if (Directory.Exists(path))
{
string json = File.ReadAllText(path);
data = JsonUtility.FromJson<T>(json);
}
else
{
data.Name = name;
}
return data;
}
}
如果您需要进一步的帮助，请随时告诉我。
英文:
The solution was found. I just needed to add the constraint Savable before the constraint new().
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.IO;
public static class SaveManager
{
public static void SaveFromJson<T>(T data, string name, string path)
{
path = Application.persistentDataPath + path;
if (!Directory.Exists(path))
{
Directory.CreateDirectory(path);
}
path = path + name + ".txt";
string json = JsonUtility.ToJson(data, true);
File.WriteAllText(path, json);
}
public static T LoadFromJson<T>(string name, string path) where T : Savable, new()
{
path = Application.persistentDataPath + path + name + ".txt";
T data = new T();
if (Directory.Exists(path))
{
string json = File.ReadAllText(path);
data = JsonUtility.FromJson<T>(json);
}
else
{
data.Name = name;
}
return data;
}
}
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论