通过动态不断增加的数据TFDMemTable定义提供的REST API数据，每次在运行时创建TGrid的性能都会降低

编程问答 2022-08-12

问题描述

我正在为iOS和Android开发Firemonkey App。我注意到，每次使用TFDMemTable REST API数据和结构在运行时创建TGrid时，该应用在iOS和Android调试中的性能都会降低。

我已经应用FreeAndNil(TGrid1);来清理TGrid，然后再创建一次。

一个值得注意的事件，每次创建TGrid时，行都以固定的7列增加，因此性能会变慢。通常，当我到达10行或记录时会发生这种情况。

我的一个大而真实的快速问题：

您认为开销在哪里导致性能下降？

  1. TGrid —我已经在创建FreeAndNil(TGrid1);之前应用了它。

  2. TFMemTable —我没有检查过，也不知道如何

  3. TButton —触发创建和向TGrid加载数据的按钮。大多数代码都驻留在这里

在这种情况下，我们假设所有其他组件都工作正常。如果您愿意的话，我可以与您分享一些代码，但可以指导我您要看到的代码。

更新1：最少的示例

FMX文件

object Form9: TForm9
  Left = 0
  Top = 0
  Caption = 'MRE TeeGrid Runtime'#13#10
  ClientHeight = 480
  ClientWidth = 294
  FormFactor.Width = 320
  FormFactor.Height = 480
  FormFactor.Devices = [Desktop]
  DesignerMasterStyle = 0
  object btn1: TButton
    Align = Bottom
    Position.Y = 440.000000000000000000
    Size.Width = 294.000000000000000000
    Size.Height = 40.000000000000000000
    Size.PlatformDefault = False
    TabOrder = 9
    Text = 'CREATE TEEGRID'
    OnClick = btn1Click
  end
  object aniSearchProcess: TAniIndicator
    Position.X = 128.000000000000000000
    Position.Y = 216.000000000000000000
  end
  object lyt1: TLayout
    Align = Client
    Size.Width = 294.000000000000000000
    Size.Height = 440.000000000000000000
    Size.PlatformDefault = False
    TabOrder = 11
  end
  object cur1: TFDGUIxWaitCursor
    Provider = 'FMX'
    Left = 32
    Top = 32
  end
  object dvr1: TFDPhysSQLiteDriverLink
    Left = 88
    Top = 32
  end
  object con1: TFDConnection
    Params.Strings = (
      'DriverID=SQLite')
    Connected = True
    LoginPrompt = False
    Left = 144
    Top = 32
  end
  object loc1: TFDLocalSQL
    Connection = con1
    Active = True
    Left = 200
    Top = 32
  end
  object rsc1: TRESTClient
    Accept = 'application/json,text/plain; q=0.9,text/html;q=0.8,'
    AcceptCharset = 'utf-8,*;q=0.8'
    BaseURL = 
      'https://me6hwinr2k.execute-api.ap-southeast-1.amazonaws.com/v0/d' +
      'bqueries?item-var=9&qty=25'
    Params = <>
    Left = 32
    Top = 112
  end
  object rsq1: TRESTRequest
    Client = rsc1
    Params = <>
    Response = rsp1
    SynchronizedEvents = False
    Left = 32
    Top = 176
  end
  object rsp1: TRESTResponse
    ContentType = 'application/json'
    Left = 32
    Top = 240
  end
  object rsd1: TRESTResponseDataSetAdapter
    Active = True
    Dataset = mtb1
    FieldDefs = <>
    Response = rsp1
    Left = 32
    Top = 304
  end
  object mtb1: TFDMemTable
    Active = True
    FieldDefs = <
      item
        Name = 'Category'
        DataType = ftWideString
        Size = 255
      end
      item
        Name = 'ID'
        DataType = ftWideString
        Size = 255
      end
      item
        Name = 'Item'
        DataType = ftWideString
        Size = 255
      end
      item
        Name = 'Qty'
        DataType = ftWideString
        Size = 255
      end
      item
        Name = 'Container'
        DataType = ftWideString
        Size = 255
      end
      item
        Name = 'Size'
        DataType = ftWideString
        Size = 255
      end
      item
        Name = 'Ex temporibus dolore consequatur.'
        DataType = ftWideString
        Size = 255
      end
      item
        Name = 'Et cum aut est nostrum...'
        DataType = ftWideString
        Size = 255
      end
      item
        Name = 'Sequi quibusdam eum.'
        DataType = ftWideString
        Size = 255
      end>
    IndexDefs = <>
    FetchOptions.AssignedValues = [evMode]
    FetchOptions.Mode = fmAll
    ResourceOptions.AssignedValues = [rvSilentMode]
    ResourceOptions.SilentMode = True
    UpdateOptions.AssignedValues = [uvCheckRequired,uvAutoCommitUpdates]
    UpdateOptions.CheckRequired = False
    UpdateOptions.AutoCommitUpdates = True
    StoreDefs = True
    Left = 32
    Top = 368
  end
end

FMX程序

unit Main;

interface

uses
  System.SysUtils,System.Types,System.UITypes,System.Classes,System.Variants,FMX.Types,FMX.Controls,FMX.Forms,FMX.Graphics,FMX.Dialogs,FireDAC.UI.Intf,FireDAC.FMXUI.Wait,FireDAC.Stan.ExprFuncs,FireDAC.Phys.SQLiteDef,FireDAC.Stan.Intf,FireDAC.Stan.Option,FireDAC.Stan.Error,FireDAC.Phys.Intf,FireDAC.Stan.Def,FireDAC.Stan.Pool,FireDAC.Stan.Async,FireDAC.Phys,FireDAC.Phys.SQLite,Data.DB,FireDAC.Stan.Param,FireDAC.DatS,FireDAC.DApt.Intf,REST.Types,FMX.Controls.Presentation,FMX.StdCtrls,FireDAC.Comp.DataSet,FireDAC.Comp.Client,REST.Response.Adapter,REST.Client,Data.Bind.Components,Data.Bind.ObjectScope,FireDAC.Phys.SQLiteVDataSet,FireDAC.Comp.UI,FMXTee.Control,FMXTee.Grid,FMX.Layouts;

type
  TForm9 = class(TForm)
    cur1: TFDGUIxWaitCursor;
    dvr1: TFDPhysSQLiteDriverLink;
    con1: TFDConnection;
    loc1: TFDLocalSQL;
    rsc1: TRESTClient;
    rsq1: TRESTRequest;
    rsp1: TRESTResponse;
    rsd1: TRESTResponseDataSetAdapter;
    mtb1: TFDMemTable;
    btn1: TButton;
    aniSearchProcess: TAniIndicator;
    lyt1: TLayout;
    procedure btn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form9: TForm9;
  tgd1: TTeeGrid;

implementation

{$R *.fmx}

procedure TForm9.btn1Click(Sender: TObject);
var
  i,CanvassItemId,e : Integer;
begin
  aniSearchProcess.Visible := True;
  aniSearchProcess.Enabled := True;
  {$IFDEF MSWINDOWS}
    Application.ProcessMessages;
  {$ENDIF}
  {$IF DEFINED(iOS) or DEFINED(ANDROID)}
    Application.HandleMessage;
  {$ENDIF}

  FreeAndNil(tgd1); //free old grid

  //create new grid
  tgd1 := TTeeGrid.Create(lyt1);
  With tgd1 do
  begin
    Parent := lyt1;
    Align := TAlignLayout.Client;
    Margins.Top := 5;
    Margins.Left := 5;
    Margins.Right := 5;
    Margins.Bottom := 5;
    ScrollBars.Visible := True;
    Header.Format.Font.Size := 11;
    Cells.Format.Font.Size := 11;
    TabOrder := 0;
    ScrollBars.Visible := False;
  end;

  con1.StartTransaction;
  try
    //define the API here for duplicate/update,initial click and subsequent clicks
    rsc1.BaseURL := 'https://0rgvn0s0gk.execute-api.ap-southeast-1.amazonaws.com/v0/dbqueries?item-var=1&qty=10';
    rsq1.Execute;
    rsd1.Active := True;
    mtb1.Active;
    tgd1.DataSource := mtb1;
    tgd1.Enabled := True;

    // adjust the column properties dynamically
    with tgd1 do
    begin
      for i := 0 to Columns.Count -1 do
      begin
        if i = 0 then
        begin
          Columns[i].Visible := False; // category column
        end
        else if (i = 1) then
        begin
          Columns[i].Visible := False; // id column
        end
        else if (i = 2) then
        begin
          Columns[i].Width.Value := 120; // item column
        end
        else if (i = 3) then
        begin
          Columns[i].Width.Value := 30; // qty column
        end
        else if (i = 4) then
        begin
          Columns[i].Width.Value := 50; // container column
        end
        else if (i = 5) then
        begin
          Columns[i].Width.Value := 50; // size column
        end
        else
        begin
          Columns[i].Width.Value := 50; // subsequent random columns
        end;
      end;
    end;
  finally
    con1.Commit;
  end;

  aniSearchProcess.Visible := False;
  aniSearchProcess.Enabled := False;
  {$IFDEF MSWINDOWS}
    Application.ProcessMessages;
  {$ENDIF}
  {$IF DEFINED(iOS) or DEFINED(ANDROID)}
    Application.HandleMessage;
  {$ENDIF}

end;

end.

解决方法

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