Question

C#.net ,报错说标准表达式中数据类型不匹配 涉及到Access中货币类型Money字段

第一次发这个问题不知为何没提交成功！！！！气人！！
主要针对AccountLog表中的Money字段，对某一个UserID，direction为IN的Money字段值的和减去direction为OUT的Money字段值，把相减得到的值用一个名为Balance的label控件显示！
代码下面：
private void BalanceInquire_Load(object sender, EventArgs e)
{

OleDbConnection oc = new OleDbConnection(ConfigurationManager.ConnectionStrings["ButterflyConnectionString"].ConnectionString);
oc.Open();

String strin = "select SUM([Money]) As income from AccountLog where UserID='" + BIUserID + "' and Direction ='IN'";
String strout = "select SUM([Money]) As payment from AccountLog Where UserID='" + BIUserID + "' and Direction = 'OUT'";

OleDbCommand comin = new OleDbCommand(strin);
comin.Connection = oc;
OleDbDataReader drin = comin.ExecuteReader();
OleDbCommand comout = new OleDbCommand(strout);
comin.Connection = oc;
OleDbDataReader drout = comout.ExecuteReader();
try
{
if (drin.Read() &&
drout.Read())
{ balance.Text = ((decimal)drin["income"] - (decimal)drout["payment"]).ToString(); }
else { MessageBox.Show("错！");} }

catch(Exception ex)
{
balance.Text = ex.Message;
}
finally
{
drin.Close();
drout.Close();
oc.Close();
}

}
}
现在第二句comin.Connection = oc;已改成comout.Connection = oc; 另外前面有代码：private static int BIUserID;
public BalanceInquire(int l1)
{
InitializeComponent();
BIUserID = l1;

}
而，再到退前面一个窗体
private void 余额查询ToolStripMenuItem_Click(object sender, EventArgs e)
{
ManageAccount.BalanceInquire frm = new ManageAccount.BalanceInquire(Login.USERID);
frm.MdiParent = this;
frm.Show();
}
再到退到主启动窗体：
public static int USERID; 这是USERID字段的定义
拜托！！！高手帮帮我啊！！！！

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Answer 1

示例已发送 请采纳 （不会不能录取吧）