ios - UIWebView 中的内存泄漏

Question

我这两天头(屁)痛。狡猾的内存泄漏使我成为绿巨人。在模拟器上分析代码时，在自定义 UIWebView 中加载任何 url 请求后会出现大量泄漏。但是，如果我使用 iPhone 5 之类的设备，则只有一个泄漏。最大的问题是 Instruments 不显示任何行 my 代码。我记得我看过一个很棒的视频教程来定位这些泄漏，但是谷歌搜索了两天没有结果:(这是一个简单的 project对于 Xcode 5，它会在 webView 属性加载 url 请求时泄漏。

截图:one , two .

UPD:添加了整个代码。UPD2:微小的重构。

#import "AKViewController.h"

@interface AKViewController ()

@property (nonatomic, strong, readonly) UIWebView *webView;

@end

@implementation AKViewController

@synthesize webView = _webView;

#define MARGIN_WEB_VIEW_X 15.0f
#define MARGIN_WEB_VIEW_TOP 30.0f
#define MARGIN_WEB_VIEW_BOTTOM 25.0f

#pragma mark - Private methods

- (CGRect)makeRectForWebView {
    CGRect appFrame = UIScreen.mainScreen.applicationFrame;
    CGRect rectWebView = CGRectMake(MARGIN_WEB_VIEW_X,
                                    MARGIN_WEB_VIEW_TOP,
                                    appFrame.size.width - MARGIN_WEB_VIEW_X * 2,
                                    appFrame.size.height - MARGIN_WEB_VIEW_BOTTOM);

    return rectWebView;
}
- (void)presentViews {
    [self.view.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];

    self.webView.frame = [self makeRectForWebView];
    [self.view addSubview:self.webView];
}
- (NSURLRequest *)makeLoginURLRequest {
    NSString *stringUrl = @"http://google.com/";
    NSURL *url = [NSURL URLWithString:[stringUrl stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];

    return request;
}

#pragma mark - Properties

- (UIWebView *)webView {
    if (!_webView) {
        _webView = [[UIWebView alloc] initWithFrame:UIScreen.mainScreen.applicationFrame];
        _webView.scalesPageToFit = YES;
    }

    return _webView;
}

#pragma mark - Lifecycle

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];

    [self presentViews];
}

- (void)viewDidLoad {
    [super viewDidLoad];

    self.view.backgroundColor = [UIColor grayColor];
    [self.webView loadRequest:[self makeLoginURLRequest]];
}

@end

帮助!

Answer 1

我不知道您是否显示了所有代码，所以我猜测您可能不会释放 Web View 的委托(delegate)。 UIWebView delegate 属性的文档说:

Important: Before releasing an instance of UIWebView for which you have set a delegate, you must first set its delegate property to nil. This can be done, for example, in your dealloc method.