未处理的“System.NullReferenceException”类型的异常出现在 Relation.dll 中。

[mygod2009mygod]

c#做控件库是出现的错误
代码如下：错误点是if (navigater.Position == 0) 请指教，谢谢！

private void UserControl1_Load(object sender, EventArgs e)
{
getconn();
string sql = "select*from Ontology_master";
DataSet dt = new DataSet();
SqlDataAdapter sda = new SqlDataAdapter(sql, conn);

sda.Fill(dt, "Ontology_master");
for (int i = 0; i < dt.Tables[0].Rows.Count; i++)
{
Label lb = GetLabel(i);
if (lb != null)
{

if (navigater.Position == 0)
{
navigater.Position = navigater.Count - 1;

lb.DataBindings.Add("Text", dt, "Ontology_master.name");
}
else
{
navigater.Position -= 1;
lb.DataBindings.Add("Text", dt, "Ontology_master.name");
}

}
conn.Close();
}



}

[Error_Code]

navigater没有初始化

[ivws_19]

[Quote=引用 1 楼 error_code 的回复:]
navigater没有初始化
[/Quote]
是的

[mygod2009mygod]

可是，我在开始已经 初始化了
BindingManagerBase navigater;

[mygod2009mygod]

我主要想实现将某一字段的所有值，分别显示在各个label中，一个lable显示一个值，如何实现啊！请帮帮我啊。我搞了几天了！都每个头绪

[mygod2009mygod]

我写的全部代码如下：请高手指点一下!
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.IO;
using System.Data.SqlClient;
using System.Net;

namespace Relation
{
[Guid("7bf8de5d-f14e-4b92-bada-28309851552d")]
public partial class UserControl1 : UserControl,IObjectSafety
{
BindingManagerBase navigater;

SqlConnection conn = new SqlConnection();

public UserControl1()
{
InitializeComponent();
}

public void GetInterfacceSafyOptions(Int32 riid, out Int32 pdwSupportedOptions, out Int32 pdwEnabledOptions)
{
// TODO: 添加 WebCamControl.GetInterfacceSafyOptions 实现
pdwSupportedOptions = 1;
pdwEnabledOptions = 2;
}

public void SetInterfaceSafetyOptions(Int32 riid, Int32 dwOptionsSetMask, Int32 dwEnabledOptions)
{
// TODO: 添加 WebCamControl.SetInterfaceSafetyOptions 实现
}
public SqlConnection getconn()
{

conn.ConnectionString ="Data Source=PC4001\\SQLEXPRESS;Initial Catalog=webdata;User ID=sa;Password=123456";
conn.Open();
return conn;
}

private Label GetLabel(int t)
{
int index = t;
foreach (Control c in this.Controls)
{
if (c.Name == ("label" + index))
{
return (Label)c;
}
}
return null;
}


private void UserControl1_Load(object sender, EventArgs e)
{
getconn();
string sql = "select*from Ontology_master";
DataSet dt = new DataSet();
SqlDataAdapter sda = new SqlDataAdapter(sql, conn);

sda.Fill(dt, "Ontology_master");
for (int i = 0; i < dt.Tables[0].Rows.Count; i++)
{
Label lb = GetLabel(i);
if (lb != null)
{

if (navigater.Position == 0)
{
navigater.Position = navigater.Count - 1;

lb.DataBindings.Add("Text", dt, "Ontology_master.name");
}
else
{
navigater.Position -= 1;
lb.DataBindings.Add("Text", dt, "Ontology_master.name");
}

}
conn.Close();
}



}

}
}

[Error_Code]

[Quote=引用 3 楼 mygod2009mygod 的回复:]
可是，我在开始已经 初始化了
BindingManagerBase navigater;
[/Quote]
这个不是初始化 这个是声明
navigater=new ....() 才是初始化

[mygod2009mygod]

请您帮帮我，我主要想实现将某一字段的所有值，分别显示在各个label中，一个lable显示一个值，如何实现啊！请帮帮我啊。我搞了几天了！都每个头绪
这个应该如何实现？感激不尽！