Android实例-解决虚拟键盘遮挡问题(XE8+小米2)

结果：

1.可以自动向上移动，来防遮挡，但同时发现个问题，如果是按硬件返回没有问题，要是点输入法(QQ、百度输入法)上的隐藏就不行了。

2.点击Edit2后出现输入法，点输入法上的隐藏后， 再点Edit2输入法不再显示。

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.ComboEdit,
   FMX.Edit, FMX.EditBox, FMX.NumberBox, FMX.DateTimeCtrls, FMX.ScrollBox,
   FMX.Memo, FMX.Controls.Presentation, FMX.StdCtrls,
   System.Math,//需要引入
   FMX.VirtualKeyboard,//需要引入
   FMX.Layouts;

 type
   TForm1 = class(TForm)
     VertScrollBox1: TVertScrollBox;
     Layout1: TLayout;
     Memo1: TMemo;
     Label1: TLabel;
     Button1: TButton;
     Edit1: TEdit;
     Edit2: TEdit;
     procedure FormCreate(Sender: TObject);
     procedure FormFocusChanged(Sender: TObject);
     procedure FormVirtualKeyboardHidden(Sender: TObject;
       KeyboardVisible: Boolean; const Bounds: TRect);
     procedure FormVirtualKeyboardShown(Sender: TObject;
       KeyboardVisible: Boolean; const Bounds: TRect);
   private
     //定义移位标记
     FKBBounds:TRectF;
     FNeedOffset: Boolean;
     procedure CalcContentBoundsProc(Sender: TObject; var ContentBounds: TRectF);
     procedure RestorePosition;
     procedure UpdateKBBounds;
     { Private declarations }
   public
     { Public declarations }
   end;

 var
   Form1: TForm1;

 implementation

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

 //赋值事件
 procedure TForm1.FormCreate(Sender: TObject);
 begin
   VertScrollBox1.OnCalcContentBounds := CalcContentBoundsProc;
 end;

 //每次焦点改变都要更新位置
 procedure TForm1.FormFocusChanged(Sender: TObject);
 begin
   UpdateKBBounds;
 end;

 //输入法隐藏时的处理
 procedure TForm1.FormVirtualKeyboardHidden(Sender: TObject;
   KeyboardVisible: Boolean; const Bounds: TRect);
 begin
   FKBBounds.Create(, , , );
   FNeedOffset := False;
   RestorePosition;
 end;

 //输入法显示时的处理
 procedure TForm1.FormVirtualKeyboardShown(Sender: TObject;
   KeyboardVisible: Boolean; const Bounds: TRect);
 begin
   FKBBounds := TRectF.Create(Bounds);
   FKBBounds.TopLeft := ScreenToClient(FKBBounds.TopLeft);
   FKBBounds.BottomRight := ScreenToClient(FKBBounds.BottomRight);
   UpdateKBBounds;
 end;

 //计算内容边界
 procedure TForm1.CalcContentBoundsProc(Sender: TObject;
   var ContentBounds: TRectF);
 begin
   if FNeedOffset and (FKBBounds.Top > ) then
   begin
     ContentBounds.Bottom := Max(ContentBounds.Bottom,  * ClientHeight - FKBBounds.Top);
   end;
 end;

 //还原位置
 procedure TForm1.RestorePosition;
 begin
   VertScrollBox1.ViewportPosition := PointF(VertScrollBox1.ViewportPosition.X, );
   Layout1.Align := TAlignLayout.Client;
   VertScrollBox1.RealignContent;
 end;

 //更新边界
 procedure TForm1.UpdateKBBounds;
 var
   LFocused : TControl;
   LFocusRect: TRectF;
 begin
   FNeedOffset := False;
   if Assigned(Focused) then
   begin
     LFocused := TControl(Focused.GetObject);
     LFocusRect := LFocused.AbsoluteRect;
     LFocusRect.Offset(VertScrollBox1.ViewportPosition);
     if (LFocusRect.IntersectsWith(TRectF.Create(FKBBounds))) and
        (LFocusRect.Bottom > FKBBounds.Top) then
     begin
       FNeedOffset := True;
       Layout1.Align := TAlignLayout.Horizontal;
       VertScrollBox1.RealignContent;
       Application.ProcessMessages;
       VertScrollBox1.ViewportPosition := PointF(VertScrollBox1.ViewportPosition.X, LFocusRect.Bottom - FKBBounds.Top);
     end;
   end;
   if not FNeedOffset then
     RestorePosition;
 end;

 end.

PS：

1.本实例来自官方demo（D:\DelphiXE8\Users\Public\Documents\Embarcadero\Studio\15.0\Samples\Object Pascal\Mobile Samples\User Interface\ScrollableForm）。

2.控件布局是VertScrollBox1、Layout1，之后的控件都是在Layout1上的。