ToStr()ToVariant()Round()Format()UpperCase()LowerCase()FormatDateTime()StrToDateTime()Max()Min()CheckedState()SelectedItem()SelectedText()
示例: 用三个 TLabel 分别呈现窗体的宽度、高度、面积. 现在窗体上添加 Label1、Label2、Label3、BindingsList1, 并激活窗体的 OnCreate 和 OnResize 事件:
unit Unit1;interfaceuses System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants, FMX.Types, FMX.Controls, FMX.Forms, FMX.Dialogs, Data.Bind.EngExt, Fmx.Bind.DBEngExt, Data.Bind.Components;type TForm1 = class(TForm) Label1: TLabel; Label2: TLabel; Label3: TLabel; BindingsList1: TBindingsList; procedure FormCreate(Sender: TObject); procedure FormResize(Sender: TObject); end;var Form1: TForm1;implementation{$R *.fmx}procedure TForm1.FormCreate(Sender: TObject);begin with TBindExpression.Create(BindingsList1) do begin ControlComponent := Label1; ControlExpression := 'Text'; SourceComponent := Form1; SourceExpression := '"宽度: " + ToStr(Width)'; Active := True; end; with TBindExpression.Create(BindingsList1) do begin ControlComponent := Label2; ControlExpression := 'Text'; SourceComponent := Form1;// SourceExpression := '"高度: " + ToStr(Height)'; SourceExpression := 'Format("高度: %s", ToStr(Height))'; //同上一行; 在表达式中使用 Format 函数时, 后面的参数不能放在 [] 中 Active := True; end; with TBindExpression.Create(BindingsList1) do begin ControlComponent := Label3; ControlExpression := 'Text'; SourceComponent := Form1; SourceExpression := '"面积: " + ToStr(Width * Height)'; Active := True; end;end;procedure TForm1.FormResize(Sender: TObject);begin BindingsList1.Notify(Sender, 'Width'); BindingsList1.Notify(Sender, 'Height');end;end. 在表达式中还可以使用关键字 Self、Owner.
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