问InnoSetup，如果选择了任何任务，则阻止安装

EN

[Setup]
AppName=My Program
AppVersion=1.5
DefaultDirName={pf}\My Program

[Tasks]
Name: client; Description: Install FTP client
Name: server; Description: Install FTP server

[Code]
// helper function
function IsAnyTaskSelected: Boolean;
begin
  Result := WizardSelectedTasks(False) <> '';
end;

// event handler for setting the next button initial state when
// entering the tasks page
procedure CurPageChanged(CurPageID: Integer);
begin
  if CurPageID = wpSelectTasks then
    WizardForm.NextButton.Enabled := IsAnyTaskSelected;
end;

// method of the task list check click event
procedure TasksListClickCheck(Sender: TObject);
begin
  WizardForm.NextButton.Enabled := IsAnyTaskSelected;
end;

procedure InitializeWizard;
begin
  WizardForm.TasksList.OnClickCheck := @TasksListClickCheck;
end;