未将对象引用设置到对象的实例。回帖给分

qqq379271395 2012-05-19 04:47:02

这句报错 string connString = ConfigurationManager.ConnectionStrings["ConnectionStrings"].ConnectionString;

我设计一个私有方法，创建数据库连接并获取金额总数赋值给Label1

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!this.IsPostBack)
{
getText();
}

}
void getText()
{
string connString = ConfigurationManager.ConnectionStrings["ConnectionStrings"].ConnectionString;
string cmdText = "select sum(gmoney) from myTable";
SqlConnection sqlcon = new SqlConnection(connString);
SqlCommand sqlcmd = sqlcon.CreateCommand();
sqlcmd.CommandText = cmdText;
sqlcon.Open();
SqlDataReader dr = sqlcmd.ExecuteReader();
if (dr.Read())
{
Label1.Text = "无人订货";
}
else
{
Label1.Text = dr.GetInt32(0).ToString() + "元";

}

sqlcon.Close();

}

protected void Timer1_Tick(object sender, EventArgs e)
{
getText();
Label1.Text += " " + DateTime.Now.ToLongDateString() + DateTime.Now.ToLongTimeString();
Label2.Text = " " + DateTime.Now.ToLongDateString() + DateTime.Now.ToLongTimeString();

GridView1.DataSourceID = "SqlDataSource1";
GridView1.DataBind();

}

}

...全文

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暖枫无敌 2012-05-19

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[Quote=引用 6 楼的回复:]
<connectionStrings>
<add name="ConnectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database.mdf;Integrated Security=True;User Instance=True"
providerNam……
[/Quote]

前后名称不一致

这句报错 string connString = ConfigurationManager.ConnectionStrings["ConnectionStrings"].ConnectionString;

多了一个s，前后要一致

孟子E章 2012-05-19

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ConfigurationManager.ConnectionStrings["ConnectionString"]
不是
ConfigurationManager.ConnectionStrings["ConnectionStrings"]

要和
<add name="ConnectionString"

名字一致

色拉油 2012-05-19

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ConfigurationManager.ConnectionStrings["ConnectionStrings"]没取到或者下面没东西了

何年 2012-05-19

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string connString = ConfigurationManager.ConnectionStrings["ConnectionStrings"].ConnectionString;

这句有错。

改成

string connString = ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();

qqq379271395 2012-05-19

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[Quote=引用 5 楼的回复:]
贴出你Web.Config文件中的数据库连接字符串来看一下
你既然使用ConnectionStrings，那么在配置节中你也要使用connectionString，而不要使用appSettings
[/Quote]
<connectionStrings>
<add name="ConnectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database.mdf;Integrated Security=True;User Instance=True"
providerName="System.Data.SqlClient" />

qqq379271395 2012-05-19

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[Quote=引用 2 楼的回复:]
string connString = ConfigurationManager.ConnectionStrings["ConnectionStrings"].ConnectionString;
这个值为空了，贴web.config里面的数据库连接字符串的代码出来啊
[/Quote]
<connectionStrings>
<add name="ConnectionString" connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database.mdf;Integrated Security=True;User Instance=True"
providerName="System.Data.SqlClient" />

qqq379271395 2012-05-19