rdlc报表数据源问题

Question

private void label1_Click(object sender, EventArgs e)
        {
            //MessageBox.Show("label1");
            this.label1.Cursor = Cursors.Hand;
            Form4 fr4 = new Form4();
            if (fr4.ShowDialog() == DialogResult.Cancel)
            {
                string xm = fr4.InputValue;                DBCon db = new DBCon();
                OleDbConnection conn = db.CreateCon();                string strSql = "select * from Revenue where InComeName='" + xm + "'";
                OleDbCommand cmd = new OleDbCommand(strSql, conn);
                OleDbDataAdapter oda = new OleDbDataAdapter(cmd);
                DataSet accountsDataSet_Revenue = new DataSet();
                try
                {
                    conn.Open();
                    oda.Fill(accountsDataSet_Revenue);
                }
                finally
                {
                    conn.Close();
                    // cmd.Dispose();
                    //conn.Dispose();
                }
                //为报表浏览器指定报表文件
                string path = @"D:\\rdlc_report\\rdlcrpt3\\rpt\\rpt\\Rev_Report.rdlc";
                reportViewer1.LocalReport.ReportPath = path;
                //指定数据集,数据集名称后为表,不是DataSet类型的数据集
                this.reportViewer1.LocalReport.DataSources.Add(new Microsoft.Reporting.WinForms.ReportDataSource("accountsDataSet", accountsDataSet_Revenue.Tables[0]));
                //显示报表
                this.reportViewer1.RefreshReport();
            }
        }        private void label3_Click(object sender, EventArgs e)
        {
            Form4 fr4 = new Form4();
            if (fr4.ShowDialog() == DialogResult.Cancel)
            {
                string xm = fr4.InputValue;
                DBCon db = new DBCon();
                OleDbConnection conn = db.CreateCon();
                string strSql = "select * from Expendtl where ExOutNo='" + xm + "'";
                OleDbCommand cmd = new OleDbCommand(strSql, conn);
                OleDbDataAdapter oda = new OleDbDataAdapter(cmd);
                DataSet Expen_ds = new DataSet();
                try
                {
                    conn.Open();
                    oda.Fill(Expen_ds);
                }
                finally
                {
                    conn.Close();
                    //cmd.Dispose();
                    //conn.Dispose();
                }
                //为报表浏览器指定报表文件
                string path = @"D:\\rdlc_report\\rdlcrpt3\\rpt\\rpt\\Expen_Report.rdlc";
                reportViewer1.LocalReport.ReportPath = path;
                //指定数据集,数据集名称后为表,不是DataSet类型的数据集
                this.reportViewer1.LocalReport.DataSources.Clear();
                this.reportViewer1.LocalReport.DataSources.Add(new Microsoft.Reporting.WinForms.ReportDataSource("Expen_ds", Expen_ds.Tables[0]));
                //显示报表
                this.reportViewer1.RefreshReport();
            }问：如果我先点label1报表显示正常，接着点label3报数据源错误，数据源为什么还是label1的数据源呢？
    如果我先点label3报表显示也正常，接着点label1报数据源错误，数据源为什么还是label3的数据源呢？

Answer 1

string path = @"D:\\rdlc_report\\rdlcrpt3\\rpt\\rpt\\Expen_Report.rdlc";后面加上 this.reportViewe1.Reset();