文檔半島外圍網上直營>>FastReport.Net教程2020(持續更新中)>>FastReport.Net中文教程:如何將選項列表傳輸到Web報表
FastReport.Net中文教程:如何將選項列表傳輸到Web報表
創建報表時,通常需要從外部傳輸一些值。這是為了將數據過濾到報表中,或管理報表的邏輯。在使用FastReport.Net的實踐中,我經常遇到這種需求。由于我主要使用Web報表,因此我通過url將參數傳遞到報表中。通常,我的報表非常復雜,并且不僅限于一個參數。因此,需要傳遞參數列表,即key值集列表。key是設置的名稱。
下面我們可以一起實踐操作一下。在這種情況下,我使用ASP. Ne Core Web Api應用程序。
namespace ParametersWeb.Models
{
public class Reports
{
// Report ID
public int Id { get; set; }
// Report File Name
public string ReportName { get; set; }
}
}
ValuesController:
填寫報表數組:
Reports[] reportItems = new Reports[]
{
new Reports { Id = 1, ReportName = "Parameters.frx" },
new Reports { Id = 2, ReportName = "Master-Detail.frx" }
};
報表的生成方法是異步的,因為它使用異步方法將html格式的報表轉換。如您所知,這種格式我們希望在瀏覽器中顯示報表:
[HttpGet("{id}")]
public async System.Threading.Tasks.TaskGetAsync(int id)
{
string mime = "application/html"; // MIME header with default value
// Find report
var parameters = HttpContext.Request.QueryString.ToString().Substring(1);
Reports reportItem = reportItems.FirstOrDefault((p) => p.Id == id); // we get the value of the collection by id
if (reportItem != null)
{
string webRootPath = _hostingEnvironment.WebRootPath; // determine the path to the wwwroot folder
string reportPath = (webRootPath + "/App_Data/" + reportItem.ReportName); // determine the path to the report
string dataPath = (webRootPath + "/App_Data/nwind.xml");// determine the path to the database
using (MemoryStream stream = new MemoryStream()) // Create a stream for the report
{
try
{
using (DataSet dataSet = new DataSet())
{
// Fill the source by data
dataSet.ReadXml(dataPath);
// Turn on web mode FastReport
Config.WebMode = true;
WebReport webReport = new WebReport();//create the report object
webReport.Report.Load(reportPath); //upload the report
webReport.Report.RegisterData(dataSet, "NorthWind"); //register the data sourcw in the report
if (parameters != null)
{
string[] parameterList = parameters.Split(',');
foreach (string item in parameterList)
{
string[] parameter = item.Split('=');
webReport.Report.SetParameterValue(parameter[0], parameter[1]); //set the report parameter value
}
}
// inline registration of FastReport javascript
webReport.Inline = true;//allow to register scripts and styles in HTML-body intead of putting them in the header
HtmlString reportHtml = await webReport.Render(); //upload the report in HTML
byte[] streamArray = Encoding.UTF8.GetBytes(reportHtml.ToString());
stream.Write(streamArray, 0, streamArray.Length);//write down the report in the stream
}
// Get the name of the resulting report file with the necessary extension
var file = String.Concat(Path.GetFileNameWithoutExtension(reportPath), ".", "html");
return File(stream.ToArray(), mime, file); // attachment
}
// Handle exceptions
catch
{
return new NoContentResult();
}
finally
{
stream.Dispose();
}
}
}
else
return NotFound();
}
此方法的邏輯本質如下:我們上傳選定的報表模板,從url解析參數并將其值傳輸到報表。然后,我們以html格式轉換報表,然后將文件返回給客戶端。
您傳遞給報表的參數名稱應與報表中的參數明確匹配:


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