怎么实现这样的字符串连接？

Question

 DataTable dt = HcPBCommBLL.GetHcPBGroupCatalogID(hashtable)我有一数据表(dt)读出来的数据如下：row catalog_id1   41
2   21
3   55
4   33怎么把列catalog_id的数据连接成 string id="41,21,55,33"谢谢

Answer 1

String id=""
for (int i=0;i<=dt.Rows.count-1;i++
{
  id=id & dt.Row[i][1] & ",";
}
id=id.TrimEnd(",");

Answer 2

DataTable dt = new DataTable("image");
        DataColumn dc1, dc2;
        dc1 = new DataColumn("row", System.Type.GetType("System.Int32"));
        dc1.AutoIncrement = true;
        dc1.AutoIncrementSeed = 1;
        dc1.AutoIncrementStep = 1;
        dt.Columns.Add(dc1);        dc2 = new DataColumn("catalog_id", System.Type.GetType("System.Int32"));
        dt.Columns.Add(dc2);        DataRow dr1 = dt.NewRow();
        dr1["catalog_id"] = 41;
        dt.Rows.Add(dr1);        DataRow dr2 = dt.NewRow();
        dr2["catalog_id"] = 21;
        dt.Rows.Add(dr2);        DataRow dr3 = dt.NewRow();
        dr3["catalog_id"] = 55;
        dt.Rows.Add(dr3);        DataRow dr4 = dt.NewRow();
        dr4["catalog_id"] = 33;
        dt.Rows.Add(dr4);        GridView1.DataSource = dt;
        GridView1.DataBind();        string id = "";        for (int i = 0, max = dt.Rows.Count; i < max; i++)
        {
            id += dt.Rows[i]["catalog_id"].ToString() + ",";
        }
        id = id.Substring(0, id.Length - 1);
        Response.Write(id);

Answer 3

怎么会报这些错呢？angel20082008错误 12 “System.Data.DataRowCollection”并不包含“count”的定义
错误 13 “System.Data.DataTable”并不包含“Row”的定义
错误 14 与“string.TrimEnd(params char[])”最匹配的重载方法具有一些无效参数
错误 15 参数“1”: 无法从“string”转换为“char[]”

Answer 4

 string PurviewIdstr = ",";
                        for (int j = 0; j < cb_purview.Items.Count; j++)
                        {
                            if (cb_purview.SelectedValue == "")
                            {
                                HongShangProject.Common.MessageBox.Show(this, "未选择任何权限,请选择！");
                            }
                            else
                            {
                                if (cb_purview.Items[j].Selected)
                                {
                                    int _pid = 0;
                                    int.TryParse(cb_purview.Items[j].Value.Trim(), out _pid);
                                    PurviewIdstr += _cid + "-" + _pid + ",";
                                }
                            }
                        }

Answer 5

缺少using System.Data;的引用

Answer 6

string str = "";
       
        foreach (DataRow dr in dt.Rows)
        {
            str = dr["catalog_id"].ToString().Trim()+",";
        }
        str = str.Remove(str.Length - 1, 1);
直接复制此代码调试既可，我已经测试过了

Answer 7

String id=""
for (int i=0;i<=dt.Rows.count-1;i++)
{
  id=id & dt.Row[i][1] & ",";
}
id=id.TrimEnd(",");我测试可以啊,你根据对应的错误修改吧