IOS使用 Visual Format Language 定义水平和垂直约束

使用 visual Format Language 在水平方向的限制条件使用的三个例子

//
//  VisualFormatLang.h
//  AutoLayoutDemo
//
//  Created by wildcat on 14-4-21.
//  Copyright (c) 2014年 com.wildcat. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface VisualFormatLang : UIViewController

@end

//
//  VisualFormatLang.m
//  AutoLayoutDemo
//
//  Created by wildcat on 14-4-21.
//  Copyright (c) 2014年 com.wildcat. All rights reserved.
//

#import "VisualFormatLang.h"

@interface VisualFormatLang ()
//添加私有属性
@property (nonatomic, strong) UITextField *textFieldEmail;
@property (nonatomic, strong) UITextField *textFieldConfirmEmail;
@property (nonatomic, strong) UIButton *registerButton;
@end

@implementation VisualFormatLang
//声明全局静态变量
NSString *const kEmailTextFieldHorizontal=@"H:|-[_textFieldEmail]-|";
NSString *const kEmailTextFieldVertical=@"V:|-[_textFieldEmail]";

NSString *const kConfirmEmailHorizontal=@"H:|-[_textFieldConfirmEmail]-|";
NSString *const kConfirmEmailVertical=@"V:[_textFieldEmail]-[_textFieldConfirmEmail]";
NSString *const kRegisterVertical=@"V:[_textFieldConfirmEmail]-[_registerButton]";

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    //构造控件
    self.textFieldEmail =[self textFieldWithPlaceholder:@"Email"];
    self.textFieldConfirmEmail =[self textFieldWithPlaceholder:@"Confirm Email"];
    self.registerButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    self.registerButton.translatesAutoresizingMaskIntoConstraints = NO;
    [self.registerButton setTitle:@"Register" forState:UIControlStateNormal];
     //添加控件到视图中
    [self.view addSubview:self.textFieldEmail];
    [self.view addSubview:self.textFieldConfirmEmail];
    [self.view addSubview:self.registerButton];
    [self.view addConstraints:[self constraints]];  //为父视图添加约束

}
//任意方向旋转
- (NSUInteger) supportedInterfaceOrientations{
    return UIInterfaceOrientationMaskAll;
}
#pragma mark - 构造UI 组件
//创建了文本框,它包含一个指定的占位符文本,
- (UITextField *) textFieldWithPlaceholder:(NSString *)paramPlaceholder{
    UITextField *result = [[UITextField alloc] init];
    result.translatesAutoresizingMaskIntoConstraints = NO;  //禁止使用autoLayout
    result.borderStyle = UITextBorderStyleRoundedRect;
    result.placeholder = paramPlaceholder;
    return result;
}

#pragma mark - 添加约束
- (NSArray *) emailTextFieldConstraints{
    NSMutableArray *result = [[NSMutableArray alloc] init];
    NSDictionary *viewsDictionary = NSDictionaryOfVariableBindings(_textFieldEmail);
    [result addObjectsFromArray:
     [NSLayoutConstraint
      constraintsWithVisualFormat:kEmailTextFieldHorizontal
                          options:0
                          metrics:nil
                            views:viewsDictionary]];
    [result addObjectsFromArray:
     [NSLayoutConstraint
      constraintsWithVisualFormat:kEmailTextFieldVertical
                          options:0
                          metrics:nil
                            views:viewsDictionary]];
    return [NSArray arrayWithArray:result];
}
- (NSArray *) confirmEmailTextFieldConstraints{
    NSMutableArray *result = [[NSMutableArray alloc] init];
    NSDictionary *viewsDictionary = NSDictionaryOfVariableBindings(_textFieldConfirmEmail, _textFieldEmail);
    [result addObjectsFromArray:
     [NSLayoutConstraint constraintsWithVisualFormat:kConfirmEmailHorizontal
                                             options:0
                                             metrics:nil
                                               views:viewsDictionary]];
    [result addObjectsFromArray:[NSLayoutConstraint
                                 constraintsWithVisualFormat:kConfirmEmailVertical
                                 options:0
                                 metrics:nil
                                 views:viewsDictionary]];
    return [NSArray arrayWithArray:result];
}

- (NSArray *) registerButtonConstraints{
    NSMutableArray *result = [[NSMutableArray alloc] init];
    NSDictionary *viewsDictionary = NSDictionaryOfVariableBindings(_registerButton, _textFieldConfirmEmail);
    [result addObject:[NSLayoutConstraint constraintWithItem:self.registerButton
                                                       attribute:NSLayoutAttributeCenterX
                                                       relatedBy:NSLayoutRelationEqual
                                                          toItem:self.view
                                                       attribute:NSLayoutAttributeCenterX
                                                      multiplier:1.0f
                                                        constant:0.0f]];
    [result addObjectsFromArray:[NSLayoutConstraint
             constraintsWithVisualFormat:kRegisterVertical
                                 options:0
                                 metrics:nil
                                   views:viewsDictionary]];
    return [NSArray arrayWithArray:result];
}
//构造并收集所有的限制 条件到一个数组里
- (NSArray *) constraints{
    NSMutableArray *result = [[NSMutableArray alloc] init];
    [result addObjectsFromArray:[self emailTextFieldConstraints]];
    [result addObjectsFromArray:[self confirmEmailTextFieldConstraints]];
    [result addObjectsFromArray:[self registerButtonConstraints]];
    return [NSArray arrayWithArray:result];
}
- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

@end

接下来学什么，请看：http://1.wildcat.sinaapp.com/?p=68

未完，待续。。。