• 無代碼不博客.實現(xiàn)太簡單不做過多介紹,邊看代碼變解釋.
• 先看效果圖片

02.gif

#import "ViewController.h"
#define kScreenW [UIScreen mainScreen].bounds.size.width
#define kScreenH [UIScreen mainScreen].bounds.size.height
#define kScreenB [UIScreen mainScreen].bounds
@interface ViewController ()<UITextFieldDelegate>

//輸入框
@property (weak, nonatomic) IBOutlet UITextField *TXTInput;

//判斷是否買了會員
@property (nonatomic, assign) BOOL isVip;

@end

• 設(shè)置TXTInput的代理,來監(jiān)聽鍵盤上return建是否被點擊.

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    /** 設(shè)置代理,監(jiān)聽鍵盤return鍵 */
    self.TXTInput.delegate = self;

}

• 下面是點擊return建調(diào)用的方法

/** 鍵盤回車return鍵調(diào)用的方法 */
- (BOOL)textFieldShouldReturn:(UITextField *)textField{

    
   UILabel * lbl = [[UILabel alloc] init];
    [self.view addSubview:lbl];
    
    /** 判斷是否是Vip */
//根據(jù)是否是Vip來設(shè)置label的背景色
    if (self.isVip) {
        
        lbl.backgroundColor = [UIColor redColor];
    } else {
    
        lbl.backgroundColor = [UIColor whiteColor];
    }
    
    lbl.text = self.TXTInput.text;
    
    /** 每次點擊return鍵后清空輸入框 */
    self.TXTInput.text = nil;
    
    /** 設(shè)置lbl自動適應(yīng)文字大小 */
    [lbl sizeToFit];
    
    CGFloat w = self.lbl.bounds.size.width;
    CGFloat h = self.lbl.bounds.size.height;
    CGFloat x = kScreenW;

//隨機產(chǎn)生y的值,來隨機產(chǎn)生lbl的高度
    CGFloat y = arc4random_uniform(kScreenH-self.lbl.bounds.size.height);
    
    lbl.frame = CGRectMake(x, y, w, h);
    
    /** 動畫執(zhí)行 */
    [UIView animateWithDuration:5.0 animations:^{
       
        lbl.frame = CGRectMake(-self.lbl.bounds.size.width, y, w, h);
    }];

    return YES;
}

• 點擊買會員按鈕,如果不是會員點擊后,變會員同時改變文字.

- (IBAction)clickVipBtn:(UIButton *)sender {
    
    if (self.isVip) {
        self.isVip = NO;
        [sender setTitle:@"買會員" forState:UIControlStateNormal];
        
        /** 存儲偏好設(shè)置或者服務(wù)器 */
        
    } else {
        [sender setTitle:@"去會員" forState:UIControlStateNormal];
        self.isVip = YES;
        /** 存儲偏好設(shè)置或者服務(wù)器 */
    }
}

思路:通過產(chǎn)生隨機數(shù)產(chǎn)生lbl的不同高度,動畫實現(xiàn)通過uiview的動畫.