LayoutSubViews - 1

最新推荐文章于 2024-06-19 10:21:48 发布

原创最新推荐文章于 2024-06-19 10:21:48 发布 · 436 阅读

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#iOS #Drawing #LayoutSubviews

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本文详细介绍了如何使用Objective-C语言，在不同屏幕方向下，自定义视图能够自动调整其子视图的布局以适应屏幕变化。通过实现`layoutSubviews`方法并结合屏幕方向通知，实现在横屏和竖屏模式下自定义视图内部子视图的正确布局。代码示例包括初始化视图、设置布局规则和响应屏幕方向改变的逻辑。

首先感谢写出这么好文章的大神：

http://bachiscoding.com/blog/2014/12/15/when-will-layoutsubviews-be-invoked/

http://www.cnblogs.com/pengyingh/articles/2417211.html

- (void)layoutSubviews;

来看看官方文档对这个方法的说明：

顾名思义，这个方式是对于subView的布局、大小等一些更新式，响应变化式的操作，上面提到另外两个方法：setNeedsLayout 和 layoutIfNeeded，我们先不讨论这额外的两个方法，我们单纯从方面的功能入手

开门见山，触发这个方法的几个最常用的（很多需要注意的地方，请移步大神博客，讲得非常好，本人的原则是在项目实际中遇到后才去甄别）

上面的几个情况我都亲自代码验证过了！参考第二篇文章，写了一个随屏幕布局变化的例子：

可以看到随屏幕方向不同，两张大图可以自己适应，但是红色框标出的自定义视图内部子视图发生了布局的变化，代码：

头文件：

@interface LBOrientationLayoutViewController : UIViewController

@end

#pragma mark - LBDynamicLayoutView

@interface  LBDynamicLayoutView: UIView

@property (nonatomic, strong) UIImageView* iconImageView;
@property (nonatomic, strong) UILabel* profileLabel;

@end

实现文件：

#import "UIColor+RandomColor.h"
#import "LBOrientationLayoutViewController.h"

@interface LBOrientationLayoutViewController ()

@property (nonatomic, strong) LBDynamicLayoutView* dynamicLayoutView;
@property (nonatomic, strong) UIImageView* stuffImageView;
@property (nonatomic, strong) UIImageView* coolImageView;

@end


@implementation LBOrientationLayoutViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(handleOrientationDidChange:) name:UIDeviceOrientationDidChangeNotification object:nil];
    
    self.stuffImageView = [[UIImageView alloc] init];
    [self.stuffImageView setFrame:CGRectMake(20, 20 + 50, self.view.frame.size.width - 40, 120)];
    [self.stuffImageView setImage:[UIImage imageNamed:@"stuff.jpg"]];
    [self.view addSubview:self.stuffImageView];
    
    self.coolImageView = [[UIImageView alloc] init];
    [self.coolImageView setFrame:CGRectMake(20,
                                            self.stuffImageView.frame.origin.y + self.stuffImageView.frame.size.height + 10,
                                            self.view.frame.size.width - 40,
                                            250 - 10 - 120)];
    [self.coolImageView setImage:[UIImage imageNamed:@"cool.jpg"]];
    [self.view addSubview:self.coolImageView];
    
    CGRect rect = CGRectMake(20,
                             self.coolImageView.frame.origin.y + self.coolImageView.frame.size.height + 10,
                             self.view.frame.size.width - 40,
                             270);
    self.dynamicLayoutView = [[LBDynamicLayoutView alloc] initWithFrame:rect];
    [self.dynamicLayoutView.profileLabel setText:@"海贼王，我当定了！"];
    [self.view addSubview:self.dynamicLayoutView];
    
}

- (void)handleOrientationDidChange:(id)sender
{
    UIInterfaceOrientation interfaceOrientation = [[UIApplication sharedApplication] statusBarOrientation];
    
    if (interfaceOrientation == UIInterfaceOrientationPortrait || interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown)
    {
        CGRect rect = CGRectMake(20,
                                 self.coolImageView.frame.origin.y + self.coolImageView.frame.size.height + 10,
                                 self.view.frame.size.width - 40,
                                 270);
        [self.dynamicLayoutView setFrame:rect];
    }
    
    else if (interfaceOrientation == UIInterfaceOrientationLandscapeLeft || interfaceOrientation == UIInterfaceOrientationLandscapeRight)
    {
        CGRect rect = CGRectMake(self.stuffImageView.frame.origin.x + self.stuffImageView.frame.size.width + 10,
                                 self.stuffImageView.frame.origin.y,
                                 self.view.frame.size.width - self.stuffImageView.frame.origin.x - self.coolImageView.frame.size.width - 10 - 20,
                                 self.stuffImageView.frame.size.height + 10 + self.coolImageView.frame.size.height);
        [self.dynamicLayoutView setFrame:rect];
    }
}


@end

#pragma mark - LBDynamicLayoutView

@implementation LBDynamicLayoutView

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    
    if (self)
    {
        self.backgroundColor = [UIColor randomColor];
        self.autoresizesSubviews = YES;
        
        self.iconImageView = [[UIImageView alloc] init];
        [self.iconImageView setFrame:CGRectMake(50, 10, self.frame.size.width - 100, 160)];
        [self.iconImageView setBackgroundColor:[UIColor randomColor]];
        [self.iconImageView setImage:[UIImage imageNamed:@"luffy.jpg"]];
        [self addSubview:self.iconImageView];
        
        self.profileLabel = [[UILabel alloc] init];
        [self.profileLabel setFrame:CGRectMake(10, self.iconImageView.frame.origin.y + self.iconImageView.frame.size.height + 10, self.frame.size.width - 20, 80)];
        [self.profileLabel setBackgroundColor:[UIColor randomColor]];
        [self.profileLabel setTextColor:[UIColor randomColor]];
        [self.profileLabel setNumberOfLines:0];
        [self addSubview:self.profileLabel];
    }
    
    
    return self;
}


- (void)layoutSubviews
{
    [super layoutSubviews];
    
    UIInterfaceOrientation interfaceOrientation = [[UIApplication sharedApplication] statusBarOrientation];
    
    if (interfaceOrientation == UIInterfaceOrientationPortrait || interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown)
    {
        [self setVerticalFrame];
    }
    
    else if (interfaceOrientation == UIInterfaceOrientationLandscapeLeft || interfaceOrientation == UIInterfaceOrientationLandscapeRight)
    {
        [self setHorizontalFrame];
    }
}

- (void)setVerticalFrame
{
    NSLog(@"竖屏");
    
    CGRect rect0 = CGRectMake(50, 10, self.frame.size.width - 100, 160);
    [self.iconImageView setFrame:rect0];
    
    CGRect rect1 = CGRectMake(10, self.iconImageView.frame.origin.y + self.iconImageView.frame.size.height + 10, self.frame.size.width - 20, 80);
    [self.profileLabel setFrame:rect1];
    
}

- (void)setHorizontalFrame
{
    NSLog(@"横屏");
    
    CGRect rect0 = CGRectMake(10, 10, 100, self.frame.size.height - 20);
    [self.iconImageView setFrame:rect0];
    
    CGRect rect1 = CGRectMake(self.iconImageView.frame.origin.x + self.iconImageView.frame.size.width + 10,
                              10,
                              self.frame.size.width - self.iconImageView.frame.origin.x - self.iconImageView.frame.size.width - 10 - 10,
                              self.frame.size.height - 20);
    [self.profileLabel setFrame:rect1];
    
}

@end

参考：

http://bachiscoding.com/blog/2014/12/15/when-will-layoutsubviews-be-invoked/

http://www.cnblogs.com/pengyingh/articles/2417211.html

http://stackoverflow.com/questions/728372/when-is-layoutsubviews-called