Question

我想创建固定尺寸的按钮，无论屏幕尺寸和方向如何，都设置为固定距离右上方的距离，但无法实现。

我尝试过以下代码，只能在纵向模式下正确显示，因为帧位置是固定的。

self.closeBtn = [UIButton buttonWithType:UIButtonTypeCustom];
self.closeBtn.frame = CGRectMake(260, 30, 50, 28);
self.closeBtn.layer.cornerRadius = 4;
self.closeBtn.layer.borderWidth = 1;
self.closeBtn.layer.borderColor = [UIColor colorWithRed:179.0/255.0 green:179.0/255.0 blue:179.0/255.0 alpha:1.0].CGColor;
[self.closeBtn setTitleColor:[UIColor colorWithRed:230.0/255.0 green:230.0/255.0 blue:230.0/255.0 alpha:1.0] forState:UIControlStateNormal];
self.closeBtn.backgroundColor = [UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0.75];
[self.closeBtn setTitle:@"Done" forState:UIControlStateNormal];
[self.closeBtn.titleLabel setFont:[UIFont fontWithName:@"HelveticaNeue-Medium" size:12.0]];
[self.closeBtn addTarget:self action:@selector(closeBtnClicked:) forControlEvents:UIControlEventTouchUpInside];

//NSLayoutConstraint* doneconstraint = [NSLayoutConstraint constraintWithItem:self.closeBtn attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeTrailing multiplier:1.0 constant:5.0];
//[self addConstraint:doneconstraint];
[self.view addSubview:self.closeBtn];

我也尝试过添加约束[取消注释2行]，但它会出现以下错误

无法同时满足约束条件。可能至少下列列表中的一个约束是您不想要的约束。试试这个：（1）看看每个约束并试着找出你不期望的东西; （2）找到添加了不需要的约束或约束的代码并修复它。（注意：如果你看到你不理解的NSAutoresizingMaskLayoutConstraints，请参阅UIView属性的文档translatesAutoresizingMaskIntoConstraints）

我对错误的猜测是框架和约束指定按钮的不同位置，但我是新手，因此我不确定发生了什么以及如何修复。

一种解决方案是改变旋转框架，但我认为使用约束将是更清洁的方法。

Answer 1

尝试此代码，只需将60替换为您想要的内容

 self.closeBtn = [UIButton buttonWithType:UIButtonTypeCustom];
self.closeBtn.frame = CGRectMake(260, 30, 50, 28);
self.closeBtn.layer.cornerRadius = 4;
self.closeBtn.layer.borderWidth = 1;
self.closeBtn.layer.borderColor = [UIColor colorWithRed:179.0/255.0 green:179.0/255.0 blue:179.0/255.0 alpha:1.0].CGColor;
[self.closeBtn setTitleColor:[UIColor colorWithRed:230.0/255.0 green:230.0/255.0 blue:230.0/255.0 alpha:1.0] forState:UIControlStateNormal];
self.closeBtn.backgroundColor = [UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0.75];
[self.closeBtn setTitle:@"Done" forState:UIControlStateNormal];
[self.closeBtn.titleLabel setFont:[UIFont fontWithName:@"HelveticaNeue-Medium" size:12.0]];
[self.view addSubview:self.closeBtn];
[self.closeBtn addTarget:self action:@selector(closeBtnClicked:) forControlEvents:UIControlEventTouchUpInside];
self.closeBtn.translatesAutoresizingMaskIntoConstraints = NO;
NSLayoutConstraint * c_1 =[NSLayoutConstraint constraintWithItem:self.view
                                                       attribute:NSLayoutAttributeRight
                                                       relatedBy:NSLayoutRelationEqual
                                                          toItem:self.closeBtn
                                                       attribute:NSLayoutAttributeRight
                                                      multiplier:1.0 constant:60];
NSLayoutConstraint * c_2 =[NSLayoutConstraint constraintWithItem:self.view
                                                       attribute:NSLayoutAttributeTop
                                                       relatedBy:NSLayoutRelationEqual
                                                          toItem:self.closeBtn
                                                       attribute:NSLayoutAttributeTop
                                                      multiplier:1.0 constant:-1*60];
NSLayoutConstraint * equal_w = [NSLayoutConstraint constraintWithItem:self.closeBtn
                                                            attribute:NSLayoutAttributeWidth
                                                            relatedBy:NSLayoutRelationEqual
                                                               toItem:nil
                                                            attribute:0
                                                           multiplier:1.0
                                                             constant:70];
NSLayoutConstraint * equal_h = [NSLayoutConstraint constraintWithItem:self.closeBtn
                                                            attribute:NSLayoutAttributeHeight
                                                            relatedBy:NSLayoutRelationEqual
                                                               toItem:nil
                                                            attribute:0
                                                           multiplier:1.0
                                                             constant:28];
[self.view addConstraints:@[c_1,c_2]];
[self.closeBtn addConstraints:@[equal_w,equal_h]];

截图是

enter image description here

目标C：以编程方式添加带有约束的UI按钮

1 个答案: