Delphi Report Builder 创建运行时组件不在屏幕上显示新标签

Question

我在报表生成器中创建一个组件以在报表上创建一组标签， 部分代码如下：

for I := 0 to 20 do begin
            Txt                 := TppLabel.Create(Report);
            Txt.Caption         := GradePipeLine.GetFieldAsString('Grade') ;
            Txt.Left            := StartLeft;
            Txt.Top             := StartTop;
            Txt.Band            := Band;
            Txt.AutoSize        := AutoSize;
            Txt.Width           := TmpWidth;
            Txt.Font            := Font;
            Txt.TextAlignment   := TextAlignment;
            Txt.Border          := Border;
            Txt.Transparent     := true;
            Txt.Tag             := -50000;
            StartLeft           := TmpEspacamento + StartLeft;
end;

此代码有效，但有问题， 当我第一次在屏幕上显示报告时，此代码创建的新标签不显示，但如果我关闭并打开预览屏幕，则创建的新 ppLabels 显示正常。 我在 ppReport 上的 BeforePrint 事件中调用此代码 有一些命令可以强制 ppReport 更新此 ppLabel 或强制使用此新标签重新加载所有报告？

Answer 1

嗯，我创建了一个小样本（见下文），它对我有用。您能否创建一个类似的示例来显示问题？

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, ppBands, ppCache, ppClass,
  ppDesignLayer, ppParameter, ppComm, ppRelatv, ppProd, ppReport, Vcl.StdCtrls,
  ppEndUsr, ppPrnabl, ppCtrls;

type
  TForm1 = class(TForm)
    ppReport1: TppReport;
    ppParameterList1: TppParameterList;
    ppDesignLayers1: TppDesignLayers;
    ppDesignLayer1: TppDesignLayer;
    ppHeaderBand1: TppHeaderBand;
    ppDetailBand1: TppDetailBand;
    ppFooterBand1: TppFooterBand;
    Button1: TButton;
    ppDesigner1: TppDesigner;
    procedure Button1Click(Sender: TObject);
    procedure ppReport1BeforePrint(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

uses
  ppIniStorage;

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  LDesigner: TppDesigner;
begin
  LDesigner := TppDesigner.Create(nil);
  try
    LDesigner.Caption := 'Invoice Report Designer';
    LDesigner.IniStorageType := TppIniNone.ClassDescription;

    LDesigner.Report := ppReport1;
    LDesigner.ShowModal;
  finally
    LDesigner.Free;
  end;
end;

procedure TForm1.ppReport1BeforePrint(Sender: TObject);
const
  TmpEspacamento = 0.7;
  StartTop = 0.1875;
  AutoSize = True;
  TmpWidth = 0.5;
var
  I: Integer;
  Txt: TppLabel;
  StartLeft: Double;
begin
  StartLeft := 0.083300002;

  for I := 0 to 2 do
  begin
            Txt                 := TppLabel.Create(ppReport1);
            Txt.Caption         := Format('Label %d', [I]);//GradePipeLine.GetFieldAsString('Grade') ;
            Txt.Left            := StartLeft;
            Txt.Top             := StartTop;
            Txt.Band            := ppHeaderBand1;
            Txt.AutoSize        := AutoSize;
            Txt.Width           := TmpWidth;
            Txt.Font            := Font;
            //Txt.TextAlignment   := TextAlignment;
            //Txt.Border          := Border;
            Txt.Transparent     := true;
            Txt.Tag             := -50000;
            StartLeft           := TmpEspacamento + StartLeft;
  end;
end;

end.

和 DFM 文件

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 290
  ClientWidth = 554
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  PixelsPerInch = 96
  TextHeight = 13
  object Button1: TButton
    Left = 12
    Top = 8
    Width = 75
    Height = 25
    Caption = 'Button1'
    TabOrder = 0
    OnClick = Button1Click
  end
  object ppReport1: TppReport
    PrinterSetup.BinName = 'Default'
    PrinterSetup.DocumentName = 'Report'
    PrinterSetup.PaperName = 'Letter'
    PrinterSetup.PrinterName = 'Default'
    PrinterSetup.SaveDeviceSettings = False
    PrinterSetup.mmMarginBottom = 6350
    PrinterSetup.mmMarginLeft = 6350
    PrinterSetup.mmMarginRight = 6350
    PrinterSetup.mmMarginTop = 6350
    PrinterSetup.mmPaperHeight = 279400
    PrinterSetup.mmPaperWidth = 215900
    PrinterSetup.PaperSize = 1
    ArchiveFileName = '($MyDocuments)\ReportArchive.raf'
    BeforePrint = ppReport1BeforePrint
    DeviceType = 'Screen'
    DefaultFileDeviceType = 'PDF'
    EmailSettings.ReportFormat = 'PDF'
    LanguageID = 'Default'
    OutlineSettings.CreateNode = True
    OutlineSettings.CreatePageNodes = True
    OutlineSettings.Enabled = True
    OutlineSettings.Visible = True
    PDFSettings.EmbedFontOptions = [efUseSubset]
    PDFSettings.EncryptSettings.AllowCopy = True
    PDFSettings.EncryptSettings.AllowInteract = True
    PDFSettings.EncryptSettings.AllowModify = True
    PDFSettings.EncryptSettings.AllowPrint = True
    PDFSettings.EncryptSettings.Enabled = False
    PDFSettings.FontEncoding = feAnsi
    PDFSettings.ImageCompressionLevel = 25
    RTFSettings.DefaultFont.Charset = DEFAULT_CHARSET
    RTFSettings.DefaultFont.Color = clWindowText
    RTFSettings.DefaultFont.Height = -13
    RTFSettings.DefaultFont.Name = 'Arial'
    RTFSettings.DefaultFont.Style = []
    TextFileName = '($MyDocuments)\Report.pdf'
    TextSearchSettings.DefaultString = '<FindText>'
    TextSearchSettings.Enabled = True
    XLSSettings.AppName = 'ReportBuilder'
    XLSSettings.Author = 'ReportBuilder'
    XLSSettings.Subject = 'Report'
    XLSSettings.Title = 'Report'
    Left = 148
    Top = 72
    Version = '14.08'
    mmColumnWidth = 0
    object ppHeaderBand1: TppHeaderBand
      Background.Brush.Style = bsClear
      mmBottomOffset = 0
      mmHeight = 13229
      mmPrintPosition = 0
    end
    object ppDetailBand1: TppDetailBand
      Background1.Brush.Style = bsClear
      Background2.Brush.Style = bsClear
      mmBottomOffset = 0
      mmHeight = 13229
      mmPrintPosition = 0
    end
    object ppFooterBand1: TppFooterBand
      Background.Brush.Style = bsClear
      mmBottomOffset = 0
      mmHeight = 13229
      mmPrintPosition = 0
    end
    object ppDesignLayers1: TppDesignLayers
      object ppDesignLayer1: TppDesignLayer
        UserName = 'Foreground'
        LayerType = ltBanded
        Index = 0
      end
    end
    object ppParameterList1: TppParameterList
    end
  end
  object ppDesigner1: TppDesigner
    Caption = 'ReportBuilder'
    DataSettings.SessionType = 'BDESession'
    DataSettings.AllowEditSQL = False
    DataSettings.GuidCollationType = gcString
    DataSettings.IsCaseSensitive = True
    DataSettings.SQLType = sqBDELocal
    Position = poScreenCenter
    IniStorageType = 'IniFile'
    IniStorageName = '($LocalAppData)\RBuilder\RBuilder.ini'
    WindowHeight = 400
    WindowLeft = 100
    WindowTop = 50
    WindowWidth = 600
    Left = 280
    Top = 164
  end
end

Answer 2

我认为问题出在插入创建标签的代码的地方。我的建议是将此代码放在ppReport1InitializeParameters 事件中。