UITextView高度随文字自动增加类似于微信

项目要求

1、UITextView的高度随文字的增加而增加，类似微信

2、多于3行不再增加UITextView的高度

3、是亲测78高度三行，根据文字大小的不同亲们自行定义，灵活运用

查了很多网站都是在

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{

   

}

或

 - (void)textViewDidChange:(UITextView *)textView{

}

中作处理，我试了一下，多多少少都有些问题，不是很完美，因此改变策略

使用通知:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textViewTextDidChange:) name:UITextViewTextDidChangeNotification object:self.textView];

总算问题少了很多，亲测目前使用还行，欢迎大家发现问题留言

源码：

@interface TextViewHeightController ()<UITextViewDelegate>

@property(nonatomic,strong) UITextView *textView;

//是否有滚动

@property (nonatomic, assign, getter=scrollFlag) BOOL flag;

@end

- (void)viewDidLoad {

    [super viewDidLoad];

   

    self.navBar.titleLabel.text = @"UITextView高度随文字自动增加";

   

   

    //UITextView

    self.textView = [[UITextView alloc]initWithFrame:CGRectMake(100, 64 + 150, SCREEN_WIDTH - 200, 30)];

    self.textView.font = [UIFont systemFontOfSize:17.0f];

    self.textView.delegate = self;

    self.textView.layer.masksToBounds = YES;

    self.textView.layer.borderWidth = 0.5;

    self.textView.layer.borderColor = [UIColor lightGrayColor].CGColor;

    //调整光标的位置，让光标出现在UITextView的正中间

    self.textView.textContainerInset = UIEdgeInsetsMake(5,0, 0, 0);

    [self.view addSubview:self.textView];

   

    //改变文字的通知

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textViewTextDidChange:) name:UITextViewTextDidChangeNotification object:self.textView];

   

    // Do any additional setup after loading the view.

}

//通知

-(void)textViewTextDidChange:(NSNotification *)notification{

   

   

    //空格使用@" "来代替

    if([_textView.text hasPrefix:@""]){

       

        _textView.text=[_textView.text stringByReplacingOccurrencesOfString:@" " withString:@""];

       

    }

   

   

    CGFloat height = _textView.contentSize.height>78?78:_textView.contentSize.height+5;

   

   

    [UIView animateWithDuration:0.3 animations:^{

       

        _textView.frame=CGRectMake(100, CGRectGetMaxY(_textView.frame)-height, _textView.frame.size.width, height);

       

       

    }];

   

   

    return;

   

}

//可以滚动

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{

   

    _flag=YES;

   

}

//不可以滚动

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{

   

    _flag=NO;

   

   

   

}

- (void)scrollViewDidScroll:(UIScrollView *)scrollView{

   

    /**

    

     *  判断是否拖动来设置frame

    

     */

   

    if(!self.scrollFlag){

       

        NSLog(@"%lf",_textView.contentSize.height);

       

        if(_textView.contentSize.height>78){

           

            [_textView setContentOffset:CGPointMake(0, _textView.contentSize.height-78 + 5)];

           

        }else{

           

          [_textView setContentOffset:CGPointMake(0, 0)];

           

           

        }

       

    }

   

}

OK ！！！！！！！！！！！