Question

我是C＃的新手。我不明白为什么构造函数（constr）和_test1在这里出错？有人可以给我一个谅解吗？

namespace ScratchPad
{
    class loading
    {

        public string _text1 = @"C:\Users\me\Documents\Defect DB\noemi.xlsx";


        string constr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + _text1 + ";Extended Properties=\"Excel 12.0 XML;HDR=YES;IMEX=1\";"; 

        OleDbConnection con = new OleDbConnection(constr);
        var selectStatement = String.Format("Select * From [{0}$]", "excel");// _test2 is not working.
        OleDbDataAdapter adaptor = new OleDbDataAdapter(selectStatement, con);

        con.Open(); // if i leave _test1 like that then, this will fail.  private string _text1;

            DataTable table = new DataTable();
        adaptor.Fill(table);

     } 
}

Answer 1

尝试将代码放在类的构造函数中，但请记住，只有在通过代码行创建Loading实例时才会触发代码。加载myloading = new Loading（）。另外，请在装载时将L大写。它是正确的类命名约定。

namespace ScratchPad
{
    class Loading
    {
     public string _text1;
     public string constr;
     public OleDbConnection con;
     public string selectStatement;
     public DataTable table;
        public Loading()
        {
        string _text1 = @"C:\Users\me\Documents\Defect DB\noemi.xlsx";


        constr = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + _text1 + ";Extended Properties=\"Excel 12.0 XML;HDR=YES;IMEX=1\";"; 

        con = new OleDbConnection(constr);
        selectStatement = String.Format("Select * From [{0}$]", "excel");// _test2 is not working.
        OleDbDataAdapter adaptor = new OleDbDataAdapter(selectStatement, con);

        con.Open(); // if i leave _test1 like that then, this will fail.  private string _text1;

         table = new DataTable();
        adaptor.Fill(table);
        }

     } 
}

字段初始值设定项无法引用非静态字段方法或属性

1 个答案: