Question

我正在开发一个Windows Phone 7应用程序，我想自动增加使用代码优先技术创建的数据库值。我尝试了以下逻辑来完成此操作，但它导致异常“方法计数不受支持”

var c = new AccountEntryModel();
Expense exp = new Expense();
if (c.Expenses.Count() == 0)
exp.ExpenseId = 1;
else
exp.ExpenseId = c.Expenses.Max<Expense>(b => b.ExpenseId) + 1;
ExpenseIdTextBox.Text = exp.ExpenseId.ToString();

Answer 1

我尝试了你的代码，它在Windows Phone 7.1中运行良好

以下是我的尝试：

var c = new AccountEntryModel();
Expense exp = new Expense();
if (c.Expenses.Count() == 0)
   exp.ExpenseId = 1;
else
   exp.ExpenseId = c.Expenses.Max<Expense>(b => b.ExpenseId) + 1;

以下是我根据您的代码在我的假设中创建的类：

public class Expense
{
    public int ExpenseId { get; set;}
}

public class AccountEntryModel
{
    public AccountEntryModel()
    {
        Expenses = new List<Expense>();

        for (int i = 1; i < 10; i++)
        {
            Expenses.Add(new Expense { ExpenseId = i });
        }

    }
    public List<Expense> Expenses { get; set;}
}

得到“不支持计数”的例外

1 个答案: