固定为UITextField和的UIButton到iPhone屏幕底部X％

Question

我有一个UITextField（input）和UIButton（_saveButton），我想坐于屏幕底部的20％时，input上述_saveButton。

看起来最好的办法是将mainScreen高度作为y边界，并且让self.view包含这两个元素坐在0的坐标上。我已经在下面试过了，但它们都是坐在屏幕的顶部。我错过了什么？

- (void)viewDidLoad { 
    [super viewDidLoad]; 

    //Text Input 
    input = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 150, 40)]; 
    input.textColor = [UIColor blackColor]; 
    input.textAlignment = NSTextAlignmentCenter; 
    input.font = [UIFont fontWithName:@"Times-New-Roman" size:25]; 
    input.backgroundColor=[UIColor whiteColor]; 
    [input setBorderStyle:UITextBorderStyleLine]; 
    [email protected]"Type words here"; 

    //The View that holds input 
    UIView *inputView = [[UIView alloc] initWithFrame:CGRectMake(100, 50, 400, 400)]; 
    [inputView addSubview:input]; 

    //Save Button 
    _saveButton = [UIButton buttonWithType: UIButtonTypeRoundedRect]; 
    _saveButton.frame = CGRectMake(0, 0, 100, 18); 
    [_saveButton setTitle:@"Save" forState:UIControlStateNormal]; 
    [_saveButton addTarget:self action:@selector(saveButtonPressed:) forControlEvents:UIControlEventTouchUpInside]; 

    //The View that holds saveButton 
    UIView *saveButtonView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 400, 400)]; 
    [saveButtonView addSubview:_saveButton]; 

    // Add input and saveButton to the main View 
    [self.view addSubview:inputView]; 
    [self.view addSubview:saveButtonView]; 

    //Fix to bottom of screen 
    float y = [UIScreen mainScreen].bounds.size.height - [UIApplication sharedApplication].statusBarFrame.size.height - self.view.frame.size.height; 
    [self.view setFrame:CGRectMake(0, y, self.view.frame.size.width, self.view.frame.size.height)]; 
} 

以下是我希望它看起来，但无需使用明确的数字，因为这将有不同的屏幕尺寸突破：

Answer 1

好吧，我砍死这个，因为我需要去作晚餐为我的孩子，但我相信它做你想做的。我错误地创造了许多额外的变量，这样你就可以直觉我在哪里做什么。

总之，你是不正确地计算inputView和saveButtonView的起源。

我已经在这里计算出它们，按照原始帖子中的要求开始沿视图的80％。我将inputView的Y起始位置设置为该80％的数字。我计算中心输入栏和保存按钮所需的X偏移量。我将saveButtonView的Y原点设置为80％加上inputView的高度加上任意的间距常数。

如果有什么不清楚的地方，请随时提问。

另外，出于好奇，你是否反对使用Storyboard和约束，而不是在代码中完成这一切？

- (void)viewDidLoad { 
     [super viewDidLoad]; 

     UITextField *input; 

     CGFloat screenWidth = [UIScreen mainScreen].bounds.size.width; 
     CGFloat screenHeight = [UIScreen mainScreen].bounds.size.height; 
     CGPoint screenOrigin = [UIScreen mainScreen].bounds.origin; 
     CGSize screenSize = [UIScreen mainScreen].bounds.size; 
     CGPoint screenCenter = CGPointMake(screenOrigin.x + (screenWidth/2), screenOrigin.y + (screenHeight/2)); 
     CGFloat topOfViews = screenHeight * 0.8; // Views begin 80% of way down view (AKA 20% from bottom) 


     //Text Input 
     input = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 150, 40)]; 
     input.textColor = [UIColor blackColor]; 
     input.textAlignment = NSTextAlignmentCenter; 
     input.font = [UIFont fontWithName:@"Times-New-Roman" size:25]; 
     input.backgroundColor=[UIColor whiteColor]; 
     [input setBorderStyle:UITextBorderStyleLine]; 
     [email protected]"Type words here"; 

     //The View that holds input 
     CGFloat inputX = screenCenter.x - input.frame.size.width/2; 
     CGFloat inputY = topOfViews; 
     CGRect inputFrame = CGRectMake(inputX, inputY, input.frame.size.width, input.frame.size.height); 
     UIView *inputView = [[UIView alloc] initWithFrame:inputFrame]; 
     [inputView addSubview:input]; 

     //Save Button 
     _saveButton = [UIButton buttonWithType: UIButtonTypeRoundedRect]; 
     _saveButton.frame = CGRectMake(0, 0, 100, 18); 
     [_saveButton setTitle:@"Save" forState:UIControlStateNormal]; 
     [_saveButton addTarget:self action:@selector(saveButtonPressed:) forControlEvents:UIControlEventTouchUpInside]; 

     //The View that holds saveButton 
     const CGFloat ARBITRARY_VERTICAL_SPACE = 24; 
     CGFloat saveX = screenCenter.x - _saveButton.frame.size.width/2; 
     CGFloat saveY = inputFrame.origin.y + inputFrame.size.height + ARBITRARY_VERTICAL_SPACE; 
     CGRect saveFrame = CGRectMake(saveX, saveY, _saveButton.frame.size.width, _saveButton.frame.size.height); 
     UIView *saveButtonView = [[UIView alloc] initWithFrame:saveFrame]; 
     [saveButtonView addSubview:_saveButton]; 

     // Add input and saveButton to the main View 
     [self.view addSubview:inputView]; 
     [self.view addSubview:saveButtonView]; 

     //Fix to bottom of screen 
     float y = [UIScreen mainScreen].bounds.size.height - [UIApplication sharedApplication].statusBarFrame.size.height - self.view.frame.size.height; 
     CGRect newFrame = CGRectMake(0, y, self.view.frame.size.width, self.view.frame.size.height); 
     [self.view setFrame:CGRectMake(0, y, self.view.frame.size.width, self.view.frame.size.height)]; 
    } 

Answer 2

我能想到的溶液是添加一个虚拟视图（用于布局目的它应该是透明的），这是整个屏幕的比例20％。并且您的UI小部件可以通过使用自动布局具有针对该虚拟视图的针。