UIVIew里面的UIButton没有集中在iPhone应用程序中

Question

我实际上是以编程方式设置一个自定义的UIView，它将包含几个UIButton，这样可以正常工作。 但我要做的是将UIButton置于我以编程方式创建的子自定义UIView中。 这是我实际使用的代码

//UIView used as a parent for the blurrEffectView
blurredPowerDown = [[UIView alloc] initWithFrame:CGRectMake(0, 0, [[UIScreen mainScreen] bounds].size.width, [[UIScreen mainScreen] bounds].size.height)];
                    blurredPowerDown.backgroundColor = [UIColor clearColor];

                    //I'm calling this for applying my custom view on top of other application (yes this is jailbreak development but issue is not related at it at all
                    window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
                    window.windowLevel = UIWindowLevelAlert + 2;
                    [window setHidden:NO];
                    [window setAlpha:1.0];
                    [window setBackgroundColor:[UIColor clearColor]];
                    [window addSubview:blurredPowerDown];

                    //Code to get blur depending of what is behind the view
                    blur = [UIBlurEffect effectWithStyle:UIBlurEffectStyleDark];
                    blurEffectView = [[UIVisualEffectView alloc]initWithEffect:blur];
                    blurEffectView.frame = blurredPowerDown.bounds;
                    blurEffectView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
                    [blurEffectView setAlpha:0.0];
                    [blurredPowerDown addSubview:blurEffectView];

                    [UIView animateWithDuration:0.5 delay:0.0 options:UIViewAnimationOptionCurveEaseIn animations:^{

            [blurEffectView setAlpha:1.0];

            }
            completion:^(BOOL finished) {

            }];

                    //This is the view I use to center all the button that I will add (in red on the following picture)
                    centerView = [[UIView alloc] init];
                    [centerView setTranslatesAutoresizingMaskIntoConstraints:NO];
                    centerView.backgroundColor = [UIColor redColor];

                    [blurEffectView addSubview:centerView];

                    [blurEffectView addConstraint:[NSLayoutConstraint constraintWithItem:centerView
                                                      attribute:NSLayoutAttributeWidth
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:blurEffectView
                                                      attribute:NSLayoutAttributeWidth
                                                     multiplier:0.7
                                                       constant:0]];

                    [blurEffectView addConstraint:[NSLayoutConstraint constraintWithItem:centerView
                                                      attribute:NSLayoutAttributeHeight
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:blurEffectView
                                                      attribute:NSLayoutAttributeHeight
                                                     multiplier:0.5
                                                       constant:0]];


                    [blurEffectView addConstraint:[NSLayoutConstraint constraintWithItem:centerView
                                                      attribute:NSLayoutAttributeCenterX
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:blurEffectView
                                                      attribute:NSLayoutAttributeCenterX
                                                     multiplier:1.0
                                                       constant:0.0]];


                    [blurEffectView addConstraint:[NSLayoutConstraint constraintWithItem:centerView
                                                      attribute:NSLayoutAttributeCenterY
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:blurEffectView
                                                      attribute:NSLayoutAttributeCenterY
                                                     multiplier:1.0
                                                       constant:0.0]];

                    //And this is the button that cause me issue
                    UIButton *cancelButton = [UIButton buttonWithType:UIButtonTypeCustom];
                    [cancelButton addTarget:self action:@selector(cancelView) forControlEvents:UIControlEventTouchUpInside];
                    [cancelButton setTitle:@"Cancel" forState:UIControlStateNormal];
                    cancelButton.frame = CGRectMake(0, 0, 80, 80);
                    cancelButton.clipsToBounds = YES;
                    cancelButton.layer.cornerRadius = 80/2.0f;
                    cancelButton.layer.borderColor=[UIColor whiteColor].CGColor;
                    cancelButton.layer.borderWidth=2.0f;


                    [centerView addSubview:cancelButton];

                    //Constraints removed as per UditS suggestion
                    [centerView addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                      attribute:NSLayoutAttributeWidth
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:centerView
                                                      attribute:NSLayoutAttributeWidth
                                                     multiplier:1.0
                                                       constant:0]];

                    [centerView addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                      attribute:NSLayoutAttributeHeight
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:centerView
                                                      attribute:NSLayoutAttributeHeight
                                                     multiplier:1.0
                                                       constant:0]];


                    [centerView addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                      attribute:NSLayoutAttributeCenterX
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:centerView
                                                      attribute:NSLayoutAttributeCenterX
                                                     multiplier:1.0
                                                       constant:0.0]];


                    [centerView addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                      attribute:NSLayoutAttributeCenterY
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:centerView
                                                      attribute:NSLayoutAttributeCenterY
                                                     multiplier:1.0
                                                       constant:0.0]];

这是它的功能截图

我真的不明白为什么我的UIButton始终保持在左上角（就好像它没有放置约束但我添加了它们！）

我真的很绝望！

在此先感谢您的帮助

编辑：如果我设置cancelButton.center = centerView.center; 这是我得到的：

EDIT2：正如所建议的那样，我设置了cancelButton.translatesAutoresizingMaskIntoConstraints = NO; 但结果如下：

编辑3：我们提前^^感谢@UditS建议（删除高度和宽度限制）按钮居中，但现在边框很奇怪

Answer 1

您应该禁用转换autoresizingMask到您的按钮的约束：

cancelButton.translatesAutoresizingMaskIntoConstraints = NO;

附加：如果要将按钮的宽度和高度设置为80px，则应在这些上替换cancelButton的2个第一个约束：

[cancelButton addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                       attribute:NSLayoutAttributeWidth
                                                       relatedBy:NSLayoutRelationEqual
                                                          toItem:nil
                                                       attribute:NSLayoutAttributeNotAnAttribute
                                                      multiplier:1.0
                                                        constant:80]];

[cancelButton addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                         attribute:NSLayoutAttributeHeight
                                                         relatedBy:NSLayoutRelationEqual
                                                            toItem:nil
                                                         attribute:NSLayoutAttributeNotAnAttribute
                                                        multiplier:1.0
                                                          constant:80]];

Answer 2

问题可能在于你的CenterY约束，就像在你的代码中你正在使cancelButton的CenterY等于centerView的CenterX。

所以代替

                [centerView addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                  attribute:NSLayoutAttributeCenterY
                                                  relatedBy:NSLayoutRelationEqual
                                                     toItem:centerView
                                                  attribute:NSLayoutAttributeCenterX
                                                 multiplier:1.0
                                                   constant:0.0]];

你应该有

                [centerView addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                  attribute:NSLayoutAttributeCenterY
                                                  relatedBy:NSLayoutRelationEqual
                                                     toItem:centerView
                                                  attribute:NSLayoutAttributeCenterY
                                                 multiplier:1.0
                                                   constant:0.0]];

根据设置后的编辑

cancelButton.translatesAutoresizingMaskIntoConstraints = NO;

按钮将占据centerView全宽和高度，因为您通过以下约束进行设置

                [centerView addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                  attribute:NSLayoutAttributeWidth
                                                  relatedBy:NSLayoutRelationEqual
                                                     toItem:centerView
                                                  attribute:NSLayoutAttributeWidth
                                                 multiplier:1.0
                                                   constant:0]];

                [centerView addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                  attribute:NSLayoutAttributeHeight
                                                  relatedBy:NSLayoutRelationEqual
                                                     toItem:centerView
                                                  attribute:NSLayoutAttributeHeight
                                                 multiplier:1.0
                                                   constant:0]];

删除这些约束并添加对称按钮的恒定高度和宽度。

根据编辑3 ，尝试向按钮添加宽度和高度约束。

                [cancelButton addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                  attribute:NSLayoutAttributeWidth
                                                  relatedBy:NSLayoutRelationEqual
                                                     toItem:nil
                                                  attribute:NSLayoutAttributeNotAnAttribute
                                                 multiplier:1.0
                                                   constant:80.0]];

                [cancelButton addConstraint:[NSLayoutConstraint constraintWithItem:cancelButton
                                                  attribute:NSLayoutAttributeHeight
                                                  relatedBy:NSLayoutRelationEqual
                                                     toItem:nil
                                                  attribute:NSLayoutAttributeNotAnAttribute
                                                 multiplier:1.0
                                                   constant:80.0]];