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我的所有方法都需要一个通用包装器,而不需要重复代码(C#)

Liam Kernighan · 技术社区 · 7 年前

我有一个函数

public TOut PerformDbOperation<TIn, TOut>(Func<IDbConnection, TIn, TOut> method, TIn param1, bool withinTransaction)
{
    IDbConnection db = GetNewDbConnection();
    OpenConnection(db);
    IDbTransaction transaction = null;

    if (withinTransaction) {
        transaction = db.BeginTransaction();
    }

    try {
        TOut result = method(db, param1);
        if (withinTransaction) {
            transaction.Commit();
        }
        return result;

    }
    finally {
        if (withinTransaction) {
            transaction.Dispose();
        }
        CloseConnection(db);
    }
}

3 回复 | 直到 7 年前

Abdou 7 年前

试试这个:

public TOut PerformDbOperation<TOut>(Function<IDbConnection,TOut> method, bool withinTransaction)
{
    IDbConnection db = GetNewDbConnection();
    OpenConnection(db);
    IDbTransaction transaction = null;

    if (withinTransaction) {
        transaction = db.BeginTransaction();
    }

    try {
        TOut result = method(db);
        if (withinTransaction) {
            transaction.Commit();
        }
        return result;

    }
    finally {
        if (withinTransaction) {
            transaction.Dispose();
        }
        CloseConnection(db);
    }
}

string s = PerformDbOperation((db) => yourMethode(db, param1, param2, param3));

如果您还需要传递不返回任何内容的methode,请使用 Action<IDbConnection> 而不是 Function<IDbConnection,TOut>

public void PerformDbOperation(Action<IDbConnection> method, bool withinTransaction)
{
     PerformDbOperation((db) => 
     {
          method(db);
          return 0;
     } 
     ,withinTransaction);  //this will call the other overload thanks to the 'return 0' stamtement
}

Olivier Jacot-Descombes 6 年前

你可以使用命令模式。

public interface IDbOperation<out TResult>
{
    TResult Result { get; }
    void Execute(IDbConnection connection);
}

实现此接口的类可以通过构造函数传递参数

public Class1 : IDbOperation<string>
{
    public Class1(int param1, double param2)
    {
        ...
    }

    public string Result { get; private set; }

    public void Execute(IDbConnection connection)
    {
        ...
        Result = ...;
    }
}

public Class2 : IDbOperation<int>
{
    public Class2(Person person)
    {
        ...
    }

    public int Result { get; private set; }

    public void Execute(IDbConnection connection)
    {
        ...
        Result = ...;
    }
}

public TOut PerformDbOperation<TOut>(IDbOperation<TOut> operation, bool withinTransaction)
{
    IDbConnection db = GetNewDbConnection();
    OpenConnection(db);
    IDbTransaction transaction = null;

    if (withinTransaction) {
        transaction = db.BeginTransaction();
    }

    try {
        operation.Execute(db);
        if (withinTransaction) {
            transaction.Commit();
        }
        return operation.Result;
    }
    finally {
        if (withinTransaction) {
            transaction.Dispose();
        }
        CloseConnection(db);
    }
}

它不需要知道操作的参数。

Bruno Warmling 7 年前

DbConnection 通过应用现有的继承。因此,在本例中,您可以有自己的方法来执行某些内容,在这个方法中,您可以执行继承的方法。