Question

我是.net开发的新手，当循环在下面的代码中得到错误，如

指数超出范围。必须是非负数且小于集合的大小。

 public void postM()
    {
        for (int i = 0; i < listCustomer.Count; i++)
        {

            var grt = listCustomer[i];
            id = grt.UserId;

            //When the loops come second time

            for (int j = 0; j < listPost.Count; j++)
            {
                //Here I'm getting the above error
                var grt1 = listPost[i];
                postId = listPost[i].PostId;
                posts1 = listPost[i].Posts;
                postTime = listPost[i].PostTimeStamp;

                DbConnection.Open();
                DbCommand = new OleDbCommand("select count(*) from mw_post where post_id = '" + postId + "'", DbConnection);
                OleDbDataReader DbReader1 = DbCommand.ExecuteReader();
                while (DbReader1.Read())
                {
                    count = DbReader1[0].ToString();
                    cnt = Convert.ToInt32(count);
                    if ((cnt == 0) && (posts != ""))
                    {
                        DbCommand = new OleDbCommand("insert into mw_post(post_id,customer_id,post,post_date,community) values('" + postId + "','" + id + "','" + posts1 + "', '" + postTime + "','LinkedIn')", DbConnection);
                        DbCommand.ExecuteNonQuery();

                        if (posts.ToUpper().Contains("Personal Loan".ToUpper()))
                        {
                            DbCommand = new OleDbCommand("UPDATE mw_post set prod_id = '2',customer_id='" + id + "' where post = '" + posts + "'", DbConnection);
                            DbCommand.ExecuteNonQuery();
                        }
                        else if (posts.ToUpper().Contains("Credit Card".ToUpper()))
                        {
                            DbCommand = new OleDbCommand("UPDATE mw_post set prod_id = '1',customer_id='" + user_id + "' where post = '" + posts + "'", DbConnection);
                            DbCommand.ExecuteNonQuery();
                        }
                        else if (posts.ToUpper().Contains("Home Loan".ToUpper()))
                        {
                            DbCommand = new OleDbCommand("UPDATE mw_post set prod_id = '3',customer_id='" + user_id + "' where post = '" + posts + "'", DbConnection);
                            DbCommand.ExecuteNonQuery();
                        }
                        else if (posts.ToUpper().Contains("Car Loan".ToUpper()))
                        {
                            DbCommand = new OleDbCommand("UPDATE mw_post set prod_id = '4',customer_id='" + user_id + "' where post = '" + posts + "'", DbConnection);
                            DbCommand.ExecuteNonQuery();
                        }
                        else if (posts.ToUpper().Contains("Deposit".ToUpper()))
                        {
                            DbCommand = new OleDbCommand("UPDATE mw_post set prod_id = '5',customer_id='" + user_id + "' where post = '" + posts + "'", DbConnection);
                            DbCommand.ExecuteNonQuery();
                        }
                        else if (posts.ToUpper().Contains("Debit Card".ToUpper()))
                        {
                            DbCommand = new OleDbCommand("UPDATE mw_post set prod_id = '7',customer_id='" + user_id + "' where post = '" + posts + "'", DbConnection);
                            DbCommand.ExecuteNonQuery();
                        }
                        else
                        {
                            DbCommand = new OleDbCommand("UPDATE mw_post set prod_id = '6',customer_id='" + user_id + "' where post = '" + posts + "'", DbConnection);
                            DbCommand.ExecuteNonQuery();
                        }
                    }
                }
                DbReader1.Close();
                DbConnection.Close();
            }
        }
    }

如何设置循环？请建议我。

有什么想法吗？提前谢谢。

Answer 1

将i更改为j：

var grt1 = listPost[j];
postId = listPost[j].PostId;
posts1 = listPost[j].Posts;
postTime = listPost[j].PostTimeStamp;

i用作listCustomer的迭代器，j用于listPost，这就是你越界的原因。

Answer 2

应该这样：

var grt1 = listPost[i];
postId = listPost[i].PostId;
posts1 = listPost[i].Posts;
postTime = listPost[i].PostTimeStamp;

取而代之的是：

var grt1 = listPost[j];
postId = listPost[j].PostId;
posts1 = listPost[j].Posts;
postTime = listPost[j].PostTimeStamp;

Answer 3

您的问题似乎是当您循环浏览listPosts时，您正在使用＆＃34; j＆＃34;循环，但然后使用＆＃34; i＆＃34;引用项目。如果＆＃34;我＆＃34;增长到大（大于listPost.Count）你会看到你看到的错误。

c＃ - 索引超出范围异常

3 个答案: