Delphi XE2 和 LiveBindings 控件之间

Question

是否可以在控件之间进行 LiveBinding，即获取 2 个编辑框并将其内容添加到一个标签中。我确信是这样，我只是不知道从哪里开始

谢谢

Answer 1

查看示例。 SVN 存储库 URL:https://radstudiodemos.svn.sourceforge.net/svnroot/radstudiodemos/branches/RadStudio_XE2/LiveBindings

一个例子:

-----Unit1.dfm -----

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 286
  ClientWidth = 426
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  PixelsPerInch = 96
  TextHeight = 13
  object Label1: TLabel
    Left = 8
    Top = 62
    Width = 48
    Height = 13
    Caption = 'Edit1Edit2'
  end
  object Edit1: TEdit
    Left = 8
    Top = 8
    Width = 121
    Height = 21
    TabOrder = 0
    Text = 'Edit1'
    OnChange = EditChange
  end
  object Edit2: TEdit
    Left = 8
    Top = 35
    Width = 121
    Height = 21
    TabOrder = 1
    Text = 'Edit2'
    OnChange = EditChange
  end
  object BindingsList1: TBindingsList
    Methods = <>
    OutputConverters = <>
    UseAppManager = True
    Left = 20
    Top = 5
    object BindExpressionLabel11: TBindExpression
      Category = 'Binding Expressions'
      ControlComponent = Label1
      SourceComponent = BindScope1
      SourceExpression = 'Edit1.Text + Edit2.Text'
      ControlExpression = 'Caption'
      NotifyOutputs = False
      Direction = dirSourceToControl
    end
  end
  object BindScope1: TBindScope
    Left = 192
    Top = 16
  end
end

-----Unit1.pas-----

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Data.Bind.EngExt, Vcl.Bind.DBEngExt,
  System.Rtti, System.Bindings.Outputs, Vcl.Bind.Editors, Data.Bind.Components,
  Vcl.StdCtrls;

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Edit2: TEdit;
    Label1: TLabel;
    BindingsList1: TBindingsList;
    BindExpressionLabel11: TBindExpression;
    BindScope1: TBindScope;
    procedure EditChange(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses
  System.Bindings.Helper;

procedure TForm1.EditChange(Sender: TObject);
begin
  TBindings.Notify(Sender, 'Text');
end;

end.

<小时/>

如何使用IDE设计器生成结果:

• 在表单 (Form1) 上放置两项编辑内容(Edit1、Edit2)、标签 (Label1) 和 TBindScope (BindScope1)。
• 为两个编辑的 OnChange 事件 (EditChange) 创建事件处理程序。
• 选择 Label1，展开 LiveBindings 属性的下拉菜单，选择“新建实时绑定(bind)...”，选择 TBindExpression
• 编辑新创建的 BindExpressionLabel11 的属性:将 Caption 分配给 ControlExpression、将 BindScope1 分配给 SourceComponent、将 Edit1.Text + Edit2.Text 分配给 SourceExpression