相关疑难解决方法(0)

我的代码适用于普通设备,但在视网膜设备上会产生模糊图像.

有人知道我的问题的解决方案吗？

+ (UIImage *) imageWithView:(UIView *)view
{
    UIGraphicsBeginImageContext(view.bounds.size);
    [view.layer renderInContext:UIGraphicsGetCurrentContext()];

    UIImage * img = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return img;
}

由于某些未知原因,iPhone 6模拟器(和设备)上的所有屏幕截图方法似乎都存在可能的错误.每当我调用任何截图方法时,包括:

snapshotViewAfterScreenUpdates:resizableSnapshotViewFromRect:drawViewHierarchyInRect:

将afterScreenUpdates设置为YES,屏幕闪烁.如果设置为NO,则不会出现闪烁,但我无法获得所需的功能.

除了iPhone 6和6+之外,这些方法在所有其他模拟器中都适用于iOS7.1和iOS8.

奇怪的是,如果我使用故事板开始一个全新的项目并尝试类似的代码,我无法重现闪烁.我使用非故事板项目附加了闪烁的GIF:

这是非常简单的视图控制器:

    @implementation TestSnapshotController

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"Snap" style:UIBarButtonItemStylePlain target:self action:@selector(_snap)];

    self.blueView = [UIView new];
    self.blueView.backgroundColor = [UIColor blueColor];
    self.blueView.frame = CGRectMake(100.0f, 100.0f, 100.0f, 100.0f);
    [self.view addSubview:self.blueView];
}

- (void)_snap
{
    [self.blueView snapshotViewAfterScreenUpdates:YES];
}

@end

这是我的AppDelegate以防万一:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

    TestSnapshotController *testVC = [TestSnapshotController new];
    UINavigationController *rootNavVC = [[UINavigationController alloc] initWithRootViewController:testVC];

    self.window.rootViewController = rootNavVC;
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window …