异常详细信息: System.InvalidOperationException: ConnectionString 属性尚未初始化。

Question

我在WEB.CONFIG里面定义咯数据库连接
然后我在其他页面引用出现错误
异常详细信息: System.InvalidOperationException: ConnectionString 属性尚未初始化。    protected void Page_Load(object sender, EventArgs e)
    {
        
        string str = System.Configuration.ConfigurationManager.AppSettings["ConnectionString"];
        OleDbConnection sqlconn = new OleDbConnection(str);
        sqlconn.Open();
        OleDbCommand songcmd = new OleDbCommand("select sbcname from scm_supplierbase where sbid='1002A'", sqlconn);
        string name = (string)songcmd.ExecuteScalar();
        Response.Write(name);
    }

Answer 1

System.Configuration.ConfigurationManager.AppSettings["ConnectionString"];
改成
System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"];
ConfigurationManager---->ConfigurationSettings

Answer 2

还是不行：
异常详细信息: System.InvalidOperationException: ConnectionString 属性尚未初始化。源错误: 
行 18:         string str = System.Configuration.ConfigurationSettings.AppSettings["ConnectionString"];
行 19:         OleDbConnection sqlconn = new OleDbConnection(str);
行 20:         sqlconn.Open();
行 21:         OleDbCommand songcmd = new OleDbCommand("select sbcname from scm_supplierbase where sbid='1002A'", sqlconn);
行 22:         string name = (string)songcmd.ExecuteScalar();
 

Answer 3

OleDBDataReader dr  = songcmd.ExecuteReader()
if(dr.Read())
{
Response.Write(dr["name"].ToString());
}

Answer 4

<add key="ConnectionString" value="Data Source=.;database=bookDB;User Id=sa;Password="/>

Answer 5

我在WEB.CONFIG的字符串连接
<connectionStrings>
<add name="ConnectionString" connectionString="Provider=MSDAORA;Data Source=XXXX;Persist Security Info=True;Password=xxxx;User ID=XXXX" providerName="System.Data.OleDb"/>
</connectionStrings>如果我在页面直接连接数据库public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {        //string str = System.Configuration.ConfigurationManager.AppSettings["ConnectionString"];
        string str="Provider=MSDAORA;Data Source=XXXX;Persist Security Info=True;Password=xxxx;User ID=XXX" providerName="System.Data.OleDb"
        OleDbConnection sqlconn = new OleDbConnection(str);
        sqlconn.Open();
        OleDbCommand songcmd = new OleDbCommand("select sbcname from scm_supplierbase where sbid='1002A'", sqlconn);
        string name = (string)songcmd.ExecuteScalar();
        Response.Write(name);
    }
}就可以正常访问

Answer 6

private readonly string SQLCONNECTIONSTRING = ConfigurationSettings.AppSettings["SQLCONNECTIONSTRING"].ToString();这样写肯定没问题！

Answer 7

异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。源错误: 
行 15:     {
行 16: 
行 17:         string str = ConfigurationSettings.AppSettings["ConnectionString"].ToString();
行 18:         //string str="Provider=MSDAORA;Data Source=rept_db;Persist Security Info=True;Password=oracle;User ID=dbusrrpt";
行 19:         OleDbConnection sqlconn = new OleDbConnection(str);
 

Answer 8

用 ConfigurationSettings.AppSettings[constr]来访问
web.config用
<appSettings>
<add key="constr" value="Privoder=Microsoft.Jet.OLEDB.4.0......">
</appSettings>
这样就好用多了啊