我该如何处理后退按钮preSS的(德尔福)Android应用程序? [英] How do I handle a back-button press in a (Delphi) Android app?
问题描述
我怎样才能让我的Android应用程序反应后退按钮?
How can I make my Android app react to the back-button?
有什么作为高层次的VCL的TApplicationEvents来处理它,或者我需要潜水深入到这里的低级别的Android特有的东西?
Is there something as high-level VCL's TApplicationEvents to handle it, or do I need to dive deep into low-level Android-specific stuff here?
目前,大多数的演示应用程序有一个屏幕上的后退按钮返回到previous屏幕。 $ P $总是pssing的psysical按钮似乎退出程序,而在某些情况下,它会导致访问冲突
Right now, most of the demo applications have an on-screen back button to go back to a previous screen. Pressing the psysical button always seems to quit the app, and in some situations it results in an access violation.
推荐答案
在表单的 OnKey ...
活动时,键
参数 vkHardwareBack
在Android上。例如:
In the form's OnKey...
events, the Key
parameter is vkHardwareBack
on Android. For example:
uses
FMX.Platform, FMX.VirtualKeyboard;
procedure TForm1.FormKeyUp(Sender: TObject; var Key: Word; var KeyChar: Char; Shift: TShiftState);
var
FService : IFMXVirtualKeyboardService;
begin
if Key = vkHardwareBack then
begin
TPlatformServices.Current.SupportsPlatformService(IFMXVirtualKeyboardService, IInterface(FService));
if (FService <> nil) and (vksVisible in FService.VirtualKeyBoardState) then
begin
// Back button pressed, keyboard visible, so do nothing...
end else
begin
// Back button pressed, keyboard not visible or not supported on this platform, lets exit the app...
if MessageDlg('Exit Application?', TMsgDlgType.mtConfirmation, [TMsgDlgBtn.mbOK, TMsgDlgBtn.mbCancel], -1) = mrOK then
begin
// Exit application here...
end else
begin
// They changed their mind, so ignore the Back button press...
Key := 0;
end;
end;
end
...
end;
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