Question

我为用户创建了一个winform，以查看我为他们创建的许多报告。我有一个带有报告名称的下拉列表，它触发相应的字段以显示参数。一旦填写完毕，他们按提交并显示报告。这是他们第一次点击屏幕时的工作原理。他们可以更改参数，ReportViewer可以正常工作。更改为其他报告，我收到以下ReportViewer错误：

An error occurred during local report processing.
An error has occurred during the report processing.
A data source instance has not been supplied for the data source "CgTempData_BusMaintenance".

就我使用的流程而言：

我将reportName（字符串）设置为物理RDLC名称。
我将dataSource（字符串）设置为DataSource名称
我在通用DataTable中填写要运行的报告数据。
使ReportViewer可见
设置LocalReport.ReportPath = "Reports\\" = reportName;
清除LocalReport.DataSources.Clear()
添加新的LocalReport.DataSources.Add(new ReportDataSource(dataSource, dt));
RefreshReport()。

以下是设置并显示ReportViewer的代码部分：

/// <summary>
/// Builds the report.
/// </summary>
private void BuildReport()
{
    DataTable dt = null;
    ReportingCG rcg = new ReportingCG();

    if (reportName == "GasUsedReport.rdlc")
    {
        dataSource = "CgTempData_FuelLog";
        CgTempData.FuelLogDataTable DtFuelLog = rcg.BuildFuelUsedTable(fromDate, toDate);
        dt = DtFuelLog;
    }
    else if (reportName == "InventoryCost.rdlc")
    {
        CgTempData.InventoryUsedDataTable DtInventory;
        dataSource = "CgTempData_InventoryUsed";
        DtInventory = rcg.BuildInventoryUsedTable(fromDate, toDate);
        dt = DtInventory;
    }
    else if (reportName == "VehicleMasterList.rdlc")
    {
        dataSource = "CgTempData_VehicleMaster";
        CgTempData.VehicleMasterDataTable DtVehicleMaster = rcg.BuildVehicleMasterTable();
        dt = DtVehicleMaster;
    }
    else if (reportName == "BusCosts.rdlc")
    {
        dataSource = "CgTempData_BusMaintenance";
        dt = rcg.BuildBusCostsTable(fromDate, toDate);
    }

    // Setup the DataSource
    this.reportViewer1.Visible = true;
    this.reportViewer1.LocalReport.ReportPath = "Reports\\" + reportName;
    this.reportViewer1.LocalReport.DataSources.Clear();
    this.reportViewer1.LocalReport.DataSources.Add(new ReportDataSource(dataSource, dt));
    this.reportViewer1.RefreshReport();
}

如何删除所有旧的剩余数据？我是否处置了对象并重新创建它？

Answer 1

我明白了。我需要在方法的开头添加：reportViewer1.Reset();。

在WinForms中切换ReportViewer中的DataSources

1 个答案: