Question

我想从下面的函数返回多个字符串。怎么做

public static string GETSTATE_SAP(string SAP)
    {
        string strState = "";
        string strSiteAdd = "";
        string strLatitude = "";
        string strLongtiude = "";
        try
        {
            OracleConnection Oraconn = new OracleConnection(ConfigurationManager.ConnectionStrings["ConnectionStringAPPSAPID"].ConnectionString);
            Oraconn.Open();
            OracleCommand cmd = new OracleCommand("Select STATE, SITE_NAME, SITE_ADDRESS, latitude, longitude from R4G_OSP.UBR where SAP_ID = '" + SAP + "'", Oraconn);
            OracleDataAdapter da = new OracleDataAdapter(cmd);
            DataTable dtSap = new DataTable();
            da.Fill(dtSap);
            strState = Convert.ToString(dtSap.Rows[0][0]);
            strSiteAdd = Convert.ToString(dtSap.Rows[0][0]);
            strLatitude = Convert.ToString(dtSap.Rows[0][0]);
            strLongtiude = Convert.ToString(dtSap.Rows[0][0]);
        }
        catch (Exception)
        {
        }
        return strState, strSiteAdd, strLatitude, strLongtiude;
    }

Answer 1

有几种方法可以返回信息，我建议你返回一个课程。这是因为信息是相关的，但没有相同的含义。当元素表示相同类型的数据时，可以使用数组或列表。例如，菜单项列表，状态信息列表等。

public class StateInfo
{
    public string State {get;set;}
    public string SiteAdd {get;set;}
    public string Latitude {get;set;}
    public string Longtiude {get;set;}
}


public static StateInfo GETSTATE_SAP(string SAP)
{
    var result = new StateInfo();

    try
    {
        OracleConnection Oraconn = new OracleConnection(ConfigurationManager.ConnectionStrings["ConnectionStringAPPSAPID"].ConnectionString);
        Oraconn.Open();
        OracleCommand cmd = new OracleCommand("Select STATE, SITE_NAME, SITE_ADDRESS, latitude, longitude from R4G_OSP.UBR where SAP_ID = '" + SAP + "'", Oraconn);
        OracleDataAdapter da = new OracleDataAdapter(cmd);
        DataTable dtSap = new DataTable();
        da.Fill(dtSap);
        result.State = Convert.ToString(dtSap.Rows[0][0]);
        result.SiteAdd = Convert.ToString(dtSap.Rows[0][0]);
        result.Latitude = Convert.ToString(dtSap.Rows[0][0]);
        result.Longtiude = Convert.ToString(dtSap.Rows[0][0]);
    }
    catch (Exception)   // <--- I'll explain below..
    {
        return null;
    }

    return result;
}

这样您就不会依赖于返回信息的顺序。这使得处理起来更容易。

用法：

var stateInfo = GETSTATE_SAP(sap);

if(stateInfo != null)
    Debug.WriteLine(stateInfo.Longtiude);

尝试/捕获您的方法：

我将你的try / catch标记为'下面的解释'。想象你用这种方法来获取你的信息，你不能“看到”出了什么问题，但信息是空的。被叫无法验证信息是否正确。要么返回null，要么不在此处捕获异常：

Answer 2

您可以使用这些字段创建自定义类并将其返回，

 public MyClass string GETSTATE_SAP(string SAP)
    {
        MyClass myObj = new MyClass();
        try
        {
            OracleConnection Oraconn = new OracleConnection(ConfigurationManager.ConnectionStrings["ConnectionStringAPPSAPID"].ConnectionString);
            Oraconn.Open();
            OracleCommand cmd = new OracleCommand("Select STATE, SITE_NAME, SITE_ADDRESS, latitude, longitude from R4G_OSP.UBR where SAP_ID = '" + SAP + "'", Oraconn);
            OracleDataAdapter da = new OracleDataAdapter(cmd);
            DataTable dtSap = new DataTable();
            da.Fill(dtSap);

            myObj.strState = Convert.ToString(dtSap.Rows[0][0]);
            myObj.strSiteAdd = Convert.ToString(dtSap.Rows[0][0]);
            myObj.strLatitude = Convert.ToString(dtSap.Rows[0][0]);
            myObj.strLongtiude = Convert.ToString(dtSap.Rows[0][0]);
        }
        catch (Exception)
        {
        }
        return myObj;
    }
    public class MyClass
    {
        public string strState { get; set; }
        public string strSiteAdd { get; set; }
        public string strLatitude { get; set; }
        public string strLongtiude { get; set; }


    }

Answer 3

您的方法返回string，因此return strState, strSiteAdd, strLatitude, strLongtiude;语句是非法的。

您可以考虑更改方法签名以返回如下所示的DataTable并返回您创建的DataTable

 public static DataTable GETSTATE_SAP(string SAP)
    {

（OR）

更改它以返回字符串数组

 public static IEnumerable<string> GETSTATE_SAP(string SAP)
    {

Answer 4

您可以选择以下任何一种

使用这些成员创建一个新的类说位置，并在您的函数中填充它，您的函数将返回它。

value = count[0];

public class location{
 public string strState = "";
 public string strSiteAdd = "";
 public string strLatitude = "";
 public string strLongtiude = "";
}

另一种选择是字典

public static location GETSTATE_SAP(string SAP)
{
    _location = new location() ;
    try
    {

     _location.strState = Convert.ToString(dtSap.Rows[0][0]);
        _location.strSiteAdd = Convert.ToString(dtSap.Rows[0][0]);
        _location.strLatitude = Convert.ToString(dtSap.Rows[0][0]);
        _location.strLongtiude = Convert.ToString(dtSap.Rows[0][0]);
}

return _location;

第三个是数据表 public static Dictionary<string,string> GETSTATE_SAP(string SAP) { Dictionary<string,string> _location = new dictionary<string,string> _location.add("strState", Convert.ToString(dtSap.Rows[0][0]));`
返回动态对象

datatable _location = new datatable(); _location.add("strState"); // add all columns _location.rows.add(Convert.ToString(dtSap.Rows[0][0]), , , ,..);

public object MyDynamicObject()
        {
            dynamic obj = new ExpandoObject();
            return obj;
        }

Answer 5

您正在使用Public方法。我个人不喜欢在公共方法中使用out参数。

但是如果您不想创建新类，那么您可以尝试以下方法。

    public static bool GETSTATE_SAP(string SAP, out string strState, out string strSiteAdd, out string strLatitude, out string strLongtiude)
        {
            strState = string.Empty;
            strSiteAdd = string.Empty;
            strLatitude = string.Empty;
            strLongtiude = string.Empty;
            try
            {
                OracleConnection Oraconn = new OracleConnection(ConfigurationManager.ConnectionStrings["ConnectionStringAPPSAPID"].ConnectionString);
                Oraconn.Open();
                OracleCommand cmd = new OracleCommand("Select STATE, SITE_NAME, SITE_ADDRESS, latitude, longitude from R4G_OSP.UBR where SAP_ID = '" + SAP + "'", Oraconn);
                OracleDataAdapter da = new OracleDataAdapter(cmd);
                DataTable dtSap = new DataTable();
                da.Fill(dtSap);
if(dtSap.Rows.Count > 0){
                strState = Convert.ToString(dtSap.Rows[0][0]);
                strSiteAdd = Convert.ToString(dtSap.Rows[0][0]);
                strLatitude = Convert.ToString(dtSap.Rows[0][0]);
                strLongtiude = Convert.ToString(dtSap.Rows[0][0]);
return true;
}
            }
            catch (Exception)
            {
            }
            return false;
        }

返回多个字符串不起作用

5 个答案: