UIToolbar不显示带有自定义视图的UIBarButtonItem(仅限iOS 11以下)

Question

我正在测试一个简单的UIToolbar,有两个UIBarButtonItem作为项目,一个使用initWithCustomView:方法构建,另一个使用initWithTitle:style:target:action:方法.

第二个按钮可以在工具栏上查看,但第一个按钮丢失了.

问题仅发生在iOS 9和iOS 10上.在iOS 11上不会发生.

有谁有想法吗？

UIToolbar *toolbar = [[UIToolbar alloc] init];
[toolbar setTranslatesAutoresizingMaskIntoConstraints:NO];

UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setTitle:@"one" forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:audioOnIcon] forState:UIControlStateNormal];

[toolbar setItems:[NSArray arrayWithObjects:
                   [[UIBarButtonItem alloc] initWithCustomView:button],
                   [[UIBarButtonItem alloc] initWithTitle:@"title" style:UIBarButtonItemStylePlain target:self action:nil],
                   nil]];

[toolbar setBackgroundImage:[UIImage new] forToolbarPosition:UIBarPositionAny barMetrics:UIBarMetricsDefault];
[toolbar setShadowImage:[UIImage new] forToolbarPosition:UIBarPositionAny];
toolbar.accessibilityIdentifier = toolbarIdentifier;

[self.view insertSubview:toolbar atIndex:[self getSubviewIndex:toolbar.accessibilityIdentifier]];

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-0-[subview]-0-|" options:NSLayoutFormatDirectionLeadingToTrailing metrics:nil views:@{ @"subview": toolbar}]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[subview]-padding-|" options:NSLayoutFormatDirectionLeadingToTrailing metrics:@{ @"padding": @(2 * PADDING) } views:@{ @"subview": toolbar }]];

Answer 1

在将其添加到工具栏之前,您需要调用该sizeToFit方法UIButton.

像这样:
[button sizeToFit]; // (Objective-C)
OR
button.sizeToFit() // (Swift)

虽然它迟到了回答这个问题,但希望这可以帮助你或其他人.