Question

我有不同类型的类，每个类都有自己的变量和函数。我在创建一个类，在内部创建一个遗传过程，该过程将对象类作为参数，并能够调用该类的变量和函数。我在创建遗传功能时遇到问题。

这是我的数据课程

class TransactionContent {
    int id, groupId;
    String category, frequency, payoutDate, amount,  status;

    TransactionContent({
        this.id,
        this.groupId,
        this.category,
        this.frequency,
        this.payoutDate,
        this.amount,
        this.status
    });

    factory TransactionContent.fromMap(Map<String, dynamic> transactionContent) => new TransactionContent(
        id: transactionContent["id"],
        groupId: transactionContent["groupId"],
        category: transactionContent["category"],
        frequency: transactionContent["frequency"],
        payoutDate: transactionContent["payoutDate"],
        amount: transactionContent["amount"],
        status: transactionContent["status"],
    );

    Map<String, dynamic> toMap() => {
        "id": id,
        "groupId": groupId,
        "category": category,
        "frequency": frequency,
        "payoutDate": payoutDate,
        "amount": amount,
        "status": status,
    };
}

class Expense implements ListItem {
    int id, groupId;
    String expenseName, frequency, paidDate, amount,  status;

    TransactionContent({
        this.id,
        this.groupId,
        this.expenseName,
        this.frequency,
        this.paidDate,
        this.amount,
        this.status
    });

    factory Expense.fromMap(Map<String, dynamic> expense) => new Expense (
        id: expense["id"],
        groupId: expense["groupId"],
        expenseName: expense["expenseName"],
        frequency: expense["frequency"],
        paidDate: expense["paidDate"],
        amount: expense["amount"],
        status: expense["status"],
    );

    Map<String, dynamic> toMap() => {
        "id": id,
        "groupId": groupId,
        "expenseName": expenseName,
        "frequency": frequency,
        "paidDate": paidDate,
        "amount": amount,
        "status": status,
    };
}

这是我试图在另一个类中创建的遗传函数。基本上，getTransactions函数将接受任何类型的类对象，例如， TransactionContent，Expense类等，然后您可以访问作为参数传递的该类的变量和函数。

getTransactions(class T) async {
    final db = await database;
    var res = await db.query('Transaction');
    List<T> transactions = res.isNotEmpty  ? res.map((trans) => T.fromMap(trans)).toList() : [];

    return transactions;
}

如何实现一个接受任何类对象并能够访问类对象变量和函数的函数？例如，如果我传递Expense的类对象，那么我应该能够像这样访问变量：

classobject.expenseName or function like classobject.ToMap().

我不想为每种类型的类创建多个函数。我正在寻找可以通过不同类型的类重用的东西。预先谢谢你

在flutter中将不同的类对象传递给函数

0 个答案: