我想问，我可以通过sqldatareader迭代吗?并在单个文本框一行中显示其值

Question

protected void Button1_Click(object sender, EventArgs e)
{
        SqlConnection MyConnection = new SqlConnection("Data Source=VIJAYSTIWARI\SQLEXPRESS;Initial Catalog=earthquake;User ID=sa;Password=HereIsPwd;");
        MyConnection.Open();
        SqlCommand MyCommand = new SqlCommand("SELECT * FROM eq", MyConnection);
        SqlDataReader mydr = MyCommand.ExecuteReader();
        if (mydr.HasRows)
        {
             while(mydr.Read())
             {
                 TextBox7.Text = mydr.GetString(1);
             }
        }
        MyConnection.Close();
    }

我的表的名称是eq，其中包含此数据：

country
---------
india
japan
mexico
afghanistan
australia
hungary

Answer 1

只需将TextBox7.Text = mydr.GetString(1);更改为：

 TextBox7.Text = TextBox7.Text + "," + mydr.GetString(1);

如果您的文本框支持多行，请执行此操作：

 TextBox7.Text = TextBox7.Text + Environment.NewLine + mydr.GetString(1);

或创建list，然后您可以使用按钮显示数据。样本：

List<string> countries = new List<string>
......
while(mydr.Read())
         {
             countries.Add(mydr.GetString(1));
 ......

然后在button_click上，使用此信息：

int myint = 0;
textBox1.Text = countries.Items[myint]
myint = myint + 1;