我写了这么个循环,想得到数据库里符合条件的所有数据,但是只能查询出一个数据,高手帮我看看代码哪里有问题?不胜感激
public void dateTimePicker1_ValueChanged(object sender, EventArgs e)
{
message = ShowOldMessage(dateTimePicker1.Value);
MessageBox.Show(message);
}
private string ShowOldMessage(DateTime dtr)
{
System.Data.OleDb.OleDbDataReader dr;
string requestdate = dateTimePicker1.Value.ToShortDateString();
string SQLstr = string.Format("select * from publicinfo where DATEDIFF(day, infodate, '{0:yyyy-MM-dd}') = 0", dtr);
dr = new server.control.ClassOptionData().ExSQLReDr(SQLstr);
ShowOldMessage som = new ShowOldMessage(); while (dr.Read())
{
som.oldMessagerichTextBox.Text += dr["info"].ToString() + "\r\n";
message= som.oldMessagerichTextBox.Text;
return message;
}
return null;
}
public void dateTimePicker1_ValueChanged(object sender, EventArgs e)
{
message = ShowOldMessage(dateTimePicker1.Value);
MessageBox.Show(message);
}
private string ShowOldMessage(DateTime dtr)
{
System.Data.OleDb.OleDbDataReader dr;
string requestdate = dateTimePicker1.Value.ToShortDateString();
string SQLstr = string.Format("select * from publicinfo where DATEDIFF(day, infodate, '{0:yyyy-MM-dd}') = 0", dtr);
dr = new server.control.ClassOptionData().ExSQLReDr(SQLstr);
ShowOldMessage som = new ShowOldMessage(); while (dr.Read())
{
som.oldMessagerichTextBox.Text += dr["info"].ToString() + "\r\n";
message= som.oldMessagerichTextBox.Text;
return message;
}
return null;
}
{
som.oldMessagerichTextBox.Text += dr["info"].ToString() + "\r\n";
message+= som.oldMessagerichTextBox.Text;
}
return message;
return null;return message;位置放错了.