destroy

问题 My Android Application has only one activity called MainActivity . When I press the back-button and run my application again, the previous activity will be destroyed. Now I want to know that is it possible to save the exact previous activity? Thank you 回答1: Pressing the back key kills your current activity. A user would not expect it to be saved as there is no way to go "Forward" . You can save the important parts of your activity in SharedPreferences or a database when you press back and

问题 I am writing a Perl script that gets data from a changing outside source. As data is added or removed from this outside source I would like the data structures in my Perl script to mirror the changes. I was able to do this by creating objects that store the data in a similar fashion and synchronizing the data in those objects whenever I try to access the data in my Perl script. This works great, and gets any new data that is added to this external source; however a problem arises when any

问题 I would like to know if there is any way I can destroy a Codeigniter library instance. What I want to do is something like this: $this->load->library('my_library'); /** Code goes here **/ $this->my_library->destoy_instance(); The reason I need to do this is because I need to liberate RAM memory while executing a large scripts. Any help will be greatly appresiated. 回答1: You can do simply like that by using unset or setting null . unset($this->my_library); OR $this->my_library = null; This

问题 I tried lot of things to overwrite the behavior of the :destroy method but nothing works. I used first the acts_as_paranoia plugin, but it doesn't work with a model in a has_many :through association. I want to overwrite :destroy method just to do something like this: def destroy _run_destroy_callbacks { delete } end def delete self.update_attribute(:status => 0) freeze end That is, I just want to update another field (status to 0) instead of destroying the record itself. 回答1: Have you tried?

问题 I have four activity, i.e. A, B, C and D. A launches B, B launches C, C launches D. When C is launching D, I want to destroy the activity B depending on the situation(logic for that will remain in activity C) so that when I go back From D, it will follow D->C->A path. So I want to destroy activity B from C. How it is possible? 回答1: finish Activity B when you are calling Activity C depends on your logic. For example if(true){ Intent in = new Intent(B.this,c.class); startActivity(c); } else {

问题 I have an object which needs to destroy itself. Can it be done? Is the example wrong? void Pawn::specialMoves(Coordinate const& from, Coordinate const& to, int passant) { /*...*/ m_board->replace(to, new Queen(m_colour));//replace pawn by queen } void Board::replace(Coordinate const &to, Piece* newPiece) { delete tile[to.x()][to.y()]; tile[to.x()][to.y()] = newPiece; } 回答1: Yes, it's legal to call delete this from inside a member function. But there's very rarely a good reason to do so

问题 What's the best way to kill a process in Java ? Get the PID and then killing it with Runtime.exec() ? Use destroyForcibly() ? What's the difference between these two methods, and is there any others solutions ? 回答1: If the process you want to kill has been started by your application Then you probably have a reference to it ( ProcessBuilder.start() or Runtime.exec() both return a reference). In this case, you can simply call p.destroy() . I think this is the cleanest way (but be careful: sub

问题 hy, i need a little help here: i use SWFupload to upload images! in the upload function i make a folder call $_SESSION['folder'] and all the files i upload are in 1 array call $_SESSION['files'] after uploads finish i print_r($_SESSION) but the array is empty? why that? this is my upload.php: if($_FILES['image']['name']) { list($name,$error) = upload('image','jpeg,jpg,png'); if($error) {$result = $error;} if($name) { // Upload Successful $result = watermark($name); print '<img src="uploads/'.

问题 As per the link http://www.xyzws.com/Servletfaq/when-is-destroy-of-servlets-called/20, one of the reason of calling destroy method is when the servlet hasn't got a request in a long time . I was thinking there could be some pages that don't get called for a long time. So, does that mean destroy will be called and they will be no longer used? Actually, I was asked this question in interview and he told me that destroy method will only be called when server is shut down. Appreciate any help on

问题 The Servlet I'm working has a variable session . I've tried session.invalidate(); , this seem to have destroyed session but when I do a redirect like so response.sendRedirect("restanes.jsp"); , it gives me HTTP Status 500 error with this line: java.lang.IllegalStateException: getAttribute: Session already invalidated This is expected since I was trying to destroy the session. But why is the page unable to redirect? On the same page elsewhere I've redirected successfully. How can I destroy