【iOS7的一些总结】使用UIView的一种有效方法
在一个典型的MVC结构中,Model部分负责保存目标数据,View部分主要负责实现数据的界面以及将数据显示出来,二者在Controller的操作下协同工作。在iOS应用中,View的实现主要由UIView及其派生类实现,主要由UILabel、UIImageView等等类来显示不同的信息。
这里展示一个demo来说明个人对UIView同数据交互的一种观点,个人意见仅供参考,欢迎讨论。
1、首先建立一个UIView的子类用于定制我们的视图对象。
头文件:
#import <UIKit/UIKit.h> @interface UserInfoView : UIView //@property (nonatomic,copy) NSString *imgString; //@property (nonatomic,copy) NSString *nameString; //@property (nonatomic,copy) NSString *addrString; //@property (nonatomic,copy) NSString *infoString; //@property (nonatomic,copy) NSString *countString; //@property (nonatomic,copy) NSString *attString; //@property (nonatomic,copy) NSString *fansString; @property (nonatomic,retain) NSDictionary *param; - (void)loadData; @endm文件:
#import "UserInfoView.h" #import "RectButton.h" @interface UserInfoView() //UI控件 @property (nonatomic,retain) UIImageView *userImage; @property (nonatomic,retain) UILabel *nameLabel; @property (nonatomic,retain) UILabel *addressLabel; @property (nonatomic,retain) UILabel *infoLabel; @property (nonatomic,retain) UILabel *countLabel; @property (nonatomic,retain) RectButton *attButton; @property (nonatomic,retain) RectButton *fansButton; @property (nonatomic,retain) UIButton *profileButton; @property (nonatomic,retain) UIButton *moreButton; //数据成员 //@property (nonatomic,copy) NSString *imgString; @property (nonatomic,copy) NSString *nameString; @property (nonatomic,copy) NSString *addrString; @property (nonatomic,copy) NSString *infoString; @property (nonatomic,copy) NSString *countString; //@property (nonatomic,copy) NSString *attString; //@property (nonatomic,copy) NSString *fansString; @end @implementation UserInfoView - (id)init { CGRect frameRect = CGRectMake(0, 0, 320, 200); self = [self initWithFrame:frameRect]; if (self) { NSLog(@"Init called"); } return self; } - (id)initWithFrame:(CGRect)frame { self = [super initWithFrame:frame]; if (self) { self.backgroundColor = [UIColor lightGrayColor]; _userImage = [[UIImageView alloc] initWithFrame:CGRectZero]; [self addSubview:_userImage]; _nameLabel = [[UILabel alloc] initWithFrame:CGRectZero]; [self addSubview:_nameLabel]; _addressLabel = [[UILabel alloc] initWithFrame:CGRectZero]; [self addSubview:_addressLabel]; _infoLabel = [[UILabel alloc] initWithFrame:CGRectZero]; [self addSubview:_infoLabel]; _attButton = [[RectButton alloc] initWithFrame:CGRectZero]; [self addSubview:_attButton]; _fansButton = [[RectButton alloc] initWithFrame:CGRectZero]; [self addSubview:_fansButton]; _profileButton = [[UIButton alloc] initWithFrame:CGRectZero]; [self addSubview:_profileButton]; _moreButton = [[UIButton alloc] initWithFrame:CGRectZero]; [self addSubview:_moreButton]; _countLabel = [[UILabel alloc] initWithFrame:CGRectZero]; [self addSubview:_countLabel]; } return self; } - (void)setParam:(NSDictionary *)param { _param = param; _nameString = [_param objectForKey:@"Name"]; _addrString = [_param objectForKey:@"Address"]; _infoString = [_param objectForKey:@"Infomation"]; _countString = [_param objectForKey:@"Count"]; [self loadData]; } - (void)layoutSubviews { _userImage.frame = CGRectMake(20, 20, 80, 80); _userImage.backgroundColor = [UIColor yellowColor]; _nameLabel.frame = CGRectMake(120, 20, 180, 20); _nameLabel.backgroundColor = [UIColor yellowColor]; _addressLabel.frame = CGRectMake(120, 50, 180, 20); _addressLabel.backgroundColor = [UIColor yellowColor]; _infoLabel.frame = CGRectMake(120, 80, 180, 20); _infoLabel.backgroundColor = [UIColor yellowColor]; _attButton.frame = CGRectMake(20, 110, 60, 60); _attButton.backgroundColor = [UIColor greenColor]; _fansButton.frame = CGRectMake(93, 110, 60, 60); _fansButton.backgroundColor = [UIColor greenColor]; _profileButton.frame = CGRectMake(167, 110, 60, 60); _profileButton.backgroundColor = [UIColor greenColor]; _moreButton.frame = CGRectMake(240, 110, 60, 60); _moreButton.backgroundColor = [UIColor greenColor]; _countLabel.frame = CGRectMake(20, 180, 280, 15); _countLabel.backgroundColor = [UIColor whiteColor]; [self loadData]; } - (void)loadData { if (self.nameString.length != 0) { _nameLabel.text = self.nameString; } if (self.addrString.length != 0) { _addressLabel.text = self.addrString; } if (self.infoString.length != 0) { _infoLabel.text = self.infoString; } if (self.countString.length != 0) { _countLabel.text = self.countString; } } @end
在这个UserInfoView新建的时候,在initWithFrame中建立各个子视图,但是只是单纯新建一个对象而已,其frame设置为0。另外,还重写了init函数,在函数中设置了指定的View大小,这样在Controller新建视图的时候不需要指定参数直接按照指定值进行操作。
UserInfoView中各个子视图的设置,在layoutSubView中完成,包括设置子视图的frame和背景颜色。layoutSubView函数可能经常被调用到,主要由以下几种情况:
- 当addSubView被调用时,被添加视图以及其子视图的layoutSubView会被调用;
- 当视图的frame发生改变时,会调用该视图的layoutSubView;
- 当滚动UIScrollView的时候会调用该视图及其父视图的layoutSubView;
- 旋转设备的时候;
- 向该视图发送setNeedLayout消息的时候。
2、由Controller向View中发送数据。
ViewController类的实现如下:
#import "ViewController.h" #import "UserInfoView.h" @interface ViewController () @property (nonatomic,retain) UIButton *People1; @property (nonatomic,retain) UIButton *People2; @property (nonatomic,retain) UserInfoView *userView; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. _userView = [[UserInfoView alloc] init]; [self.view addSubview:_userView]; _People1 = [UIButton buttonWithType:UIButtonTypeSystem]; _People1.frame = CGRectMake(20, 240, 120, 40); [_People1 setTitle:@"张三" forState:UIControlStateNormal]; _People1.backgroundColor = [UIColor lightGrayColor]; [_People1 addTarget:self action:@selector(setPeople1Data) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:_People1]; _People2 = [UIButton buttonWithType:UIButtonTypeSystem]; _People2.frame = CGRectMake(180, 240, 120, 40); [_People2 setTitle:@"李四" forState:UIControlStateNormal]; _People2.backgroundColor = [UIColor lightGrayColor]; [_People2 addTarget:self action:@selector(setPeople2Data) forControlEvents:UIControlEventTouchUpInside]; [self.view addSubview:_People2]; /* view.nameString = @"张三"; view.addrString = @"北京"; view.infoString = @"学生"; view.countString = @"12345"; view.nameString = @"李四"; view.addrString = @"上海"; view.infoString = @"工程师"; view.countString = @"54321";*/ } - (void)setPeople1Data { NSLog(@"setPeople1Data called."); NSDictionary *param = @{@"Name": @"张三", @"Address" : @"北京", @"Infomation" : @"学生", @"Count" : @"12345"}; _userView.param = param; } - (void)setPeople2Data { NSLog(@"setPeople2Data called."); NSDictionary *param = @{@"Name": @"李四", @"Address" : @"上海", @"Infomation" : @"工程师", @"Count" : @"54321"}; _userView.param = param; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } @end
ViewController的默认视图上,分别实现了两个按钮并分别设置了响应函数。我们的目的是通过选择不同的按钮来改变UserInfoView中显示的数据。从两个响应函数setPeople1Data和setPeople2Data的实现可知,UserInfoView所需要的信息都被封装在了一个字典型变量param中,对view的修改仅仅做了一个操作,即将该字典变量赋给了UserInfoView实例的一个property,通过这种改变一下目标view属性的方式即可完成对显示信息的更改。这样,Controller并不关心UserInfoView实例是如何解析字典参数的,也不需要对该实例进行其他操作,当需要更新数据的时候只需要一次赋值就可以了。如此可以最大程度地解除Controller和View的耦合性,提高代码的逻辑简洁度和可复用性。
再回到UserInfoView类中的实现方法。如何实现在字典类property改变的同时对自己的子视图进行重写数据操作呢?方法很简单。首先将重写子视图数据的代码分离到loadData函数中,然后重写NSDictionary *param这个property的set方法(即setParam),然后在该set方法和layoutSubView方法中调用loadData方法就可以了。
demo下载链接:点这里。
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