可可ARC:从内存中删除窗口 [英] Cocoa ARC: Remove window from memory

问题描述

我有一个属性:

@property (strong, nonatomic) NSWindow *window;

在我的实现中，我有两种方法，分别是start和stop.

And in my implementation, I have two methods, start and stop.

启动功能会像这样(部分代码)创建一个新窗口:

The start function creates a new window like so (partial code) :

_window = [[NSWindow alloc] initWithContentRect:screenRect
                                           styleMask:NSBorderlessWindowMask
                                             backing:NSBackingStoreBuffered
                                               defer:NO];

停止功能将关闭窗口，如下所示:

The stop function closes the window like so:

[_window orderOut:self];
[_window close];
//_window = nil;

但是，当我第二次执行启动功能(启动，然后停止，然后再次启动)时，出现EXC_BAD_ACCESS错误.

However, I get an EXC_BAD_ACCESS error when I execute the start function for the second time (start, then stop, then start again).

这发生在NSWindow的alloc语句上.

This happens on the NSWindow alloc statement.

我该怎么做才能确保正确创建一个新窗口?

What do I need to do to make sure that a new window is created correctly?

经过更多测试，看来该错误与alloc init调用无关.如果在此之前添加以下行:

 NSLog(@"%@", _window);

在第一次调用start时，将导致输出"null"，然后在调用stop()和新的start调用之后，我将在NSLog行上收到EXC_BAD_ACCESS错误.

On first call to start, this will result in output "null", then after the call to stop() and the new call to start, I will get a EXC_BAD_ACCESS error on the NSLog line.

即使只是设置_window = nil;在stop方法中(调用[_window close];之后)会导致严重的访问错误.

Even just setting _window = nil; in the stop method (after calling [_window close];) causes a bad access error.

推荐答案

您需要添加什么:

_window = [[NSWindow alloc] initWithContentRect:screenRect
                                           styleMask:NSBorderlessWindowMask
                                             backing:NSBackingStoreBuffered
                                               defer:NO];
[_window setReleasedWhenClosed:NO];

出现EXC_BAD_ACCESS错误的原因是 该窗口设置为在关闭时被释放，释放消息为当前事件完成后发送给该对象.对于NSWindow对象，默认值是在关闭时释放.

The reason you got an EXC_BAD_ACCESS error is the window is set to be released when closed, a release message is sent to the object after the current event is completed. For an NSWindow object, the default is to be released on closing.

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