Android实例-TTabControl的使用(XE8+小米2)

结果： 

1.如果直接改变Tab的TabIndex，那样是没有动态效果的。如果想要动态效果需要用到ChangeTabAction1;

2.ChangeTabAction1可以直接为按钮指定Action这样不写代码，也可以支持动态效果。

3.ExecuteTarget是执行跳转功能，查看源代码，没有找到参数是做什么的。所以真心不明白里面的参数是什么意思。希望哪位前辈指点。

4.有人可能感觉出来了，为什么Android上的QQ、微信什么的手势都那么好用，而Delphi的有时不好使。其实不是这样的。那是因为Delphi中是直线向左、向右才识别。有关手势的我会重写文章说明，此文只是对Tab控件的功能介绍。

实例代码：

 unit Unit1;

 interface

 uses
   System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,
   FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs,
   FMX.Controls.Presentation, FMX.StdCtrls, FMX.ListBox, FMX.Layouts,
   FMX.TabControl, System.Actions, FMX.ActnList, FMX.NumberBox, FMX.Edit,
   FMX.EditBox, FMX.SpinBox, FMX.Gestures;

 type
   TForm1 = class(TForm)
     TabControl1: TTabControl;
     Layout1: TLayout;
     ComboBox1: TComboBox;
     Label1: TLabel;
     TabItem1: TTabItem;
     TabItem2: TTabItem;
     TabItem3: TTabItem;
     TabItem4: TTabItem;
     Button1: TButton;
     Button2: TButton;
     ActionList1: TActionList;
     ChangeTabAction1: TChangeTabAction; //手动增加的Action
     ChangeTabAction2: TChangeTabAction; //手动增加的Action
     ChangeTabAction3: TChangeTabAction; //手动增加的Action
     ChangeTabAction4: TChangeTabAction; //手动增加的Action
     Button3: TButton;
     Button4: TButton;
     Button5: TButton;
     Button6: TButton;
     Button7: TButton;
     Button8: TButton;
     Button11: TButton;
     Button12: TButton;
     GestureManager1: TGestureManager; //手动增加的控件
     Label2: TLabel;
     Label3: TLabel;
     Label4: TLabel;
     Label5: TLabel;
     procedure Button1Click(Sender: TObject);
     procedure Button2Click(Sender: TObject);
     procedure Button7Click(Sender: TObject);
     procedure Button8Click(Sender: TObject);
     procedure Button11Click(Sender: TObject);
     procedure Button12Click(Sender: TObject);
     procedure ComboBox1Change(Sender: TObject);
     procedure TabControl1Gesture(Sender: TObject;
       const EventInfo: TGestureEventInfo; var Handled: Boolean);
     procedure FormKeyUp(Sender: TObject; var Key: Word; var KeyChar: Char;
       Shift: TShiftState);
     procedure FormCreate(Sender: TObject);
   private
     { Private declarations }
   public
     { Public declarations }
   end;

 var
   Form1: TForm1;

 implementation

 {$R *.fmx}
 {$R *.NmXhdpiPh.fmx ANDROID}

 //为了实现手势必须做的设置
 procedure TForm1.FormCreate(Sender: TObject);
 begin
   //为Tab指定一个手势控件
   TabControl1.Touch.GestureManager := GestureManager1;
   //设置Tab控件支持的手势有哪些(如果这一项不设置，手势是没有反映的)
   TabControl1.Touch.StandardGestures := [TStandardGesture.sgLeft, TStandardGesture.sgRight];
 end;

 //Action上一页
 procedure TForm1.Button11Click(Sender: TObject);
 begin
   if TabControl1.TabIndex >  then
   begin
     ChangeTabAction1.Tab := TTabItem(Form1.FindComponent('TabItem' + IntToStr(TabControl1.TabIndex)));
     ChangeTabAction1.ExecuteTarget(Self);
   end;
 end;

 //Action下一页
 procedure TForm1.Button12Click(Sender: TObject);
 begin
   if TabControl1.TabIndex < TabControl1.TabCount -  then
   begin
     ChangeTabAction1.Tab := TTabItem(Form1.FindComponent('TabItem' + IntToStr(TabControl1.TabIndex + )));
     ChangeTabAction1.ExecuteTarget(Self);
   end;
 end;

 //Tab上一页
 procedure TForm1.Button1Click(Sender: TObject);
 begin
   if TabControl1.TabIndex >  then
   begin
     TabControl1.TabIndex := TabControl1.TabIndex - ;
   end;
 end;

 //Tab下一页
 procedure TForm1.Button2Click(Sender: TObject);
 begin
   if TabControl1.TabIndex < TabControl1.TabCount -  then
   begin
     TabControl1.TabIndex := TabControl1.TabIndex + ;
   end;
 end;

 //ExecuteTarget方法1
 procedure TForm1.Button7Click(Sender: TObject);
 begin
   ChangeTabAction1.ExecuteTarget(self);
 end;

 //ExecuteTarget方法2
 procedure TForm1.Button8Click(Sender: TObject);
 begin
   ChangeTabAction1.ExecuteTarget(TabControl1);
 end;

 procedure TForm1.ComboBox1Change(Sender: TObject);
 begin
   case ComboBox1.ItemIndex of
     : TabControl1.TabPosition := TTabPosition.PlatformDefault;
     : TabControl1.TabPosition := TTabPosition.Top;
     : TabControl1.TabPosition := TTabPosition.Bottom;
     : TabControl1.TabPosition := TTabPosition.None;
     : TabControl1.TabPosition := TTabPosition.Dots;
   end;
 end;

 //利用手机的返回键实现Tab跳转
 procedure TForm1.FormKeyUp(Sender: TObject; var Key: Word; var KeyChar: Char;
   Shift: TShiftState);
 begin
   if Key = vkHardwareBack then
   begin
     if TabControl1.TabIndex >  then
     begin
       TabControl1.TabIndex := TabControl1.TabIndex -  mod TabControl1.TabCount;
       Key := ;
     end;
   end;
 end;

 //利用手势实现Tab跳转
 procedure TForm1.TabControl1Gesture(Sender: TObject;
   const EventInfo: TGestureEventInfo; var Handled: Boolean);
 begin
   case EventInfo.GestureID of
     sgiLeft:
     begin
       case TabControl1.TabIndex of
         : ChangeTabAction2.ExecuteTarget(self);
         : ChangeTabAction3.ExecuteTarget(self);
         : ChangeTabAction4.ExecuteTarget(self);
       end;
     end;
     sgiRight:
     begin
       case TabControl1.TabIndex of
         : ChangeTabAction3.ExecuteTarget(self);
         : ChangeTabAction2.ExecuteTarget(self);
         : ChangeTabAction1.ExecuteTarget(self);
       end;
     end;
   end;
   Handled := True;
 end;

 end.