UITextView

有的时候开发往往需要使用到与textField相似但是又有些不同的控件textView.介绍一些常见用法

//MARK:修改键盘上返回按钮的状态
self.groupNameTextView.returnKeyType = UIReturnKeyDone;
//MARK:设置代理
self.groupManifestoTextView.delegate = self;

#pragma mark - textView设置与textField边框一样的灰色边框,可以试用与给所有的系统控件添加bian
- (void)changeTextView:(UITextView *)textView {
    textView.layer.borderColor = [[UIColor colorWithRed:215.0 / 255.0 green:215.0 / 255.0 blue:215.0 / 255.0 alpha:1] CGColor];
    textView.layer.borderWidth = 0.6f;
    textView.layer.cornerRadius = 6.0f;
}
#pragma mark - 键盘退出的方法
（1）如果你程序是有导航条的，可以在导航条上面加多一个Done的按钮，用来退出键盘，当然要先实现UITextViewDelegate。
- (void)textViewDidBeginEditing:(UITextView *)textView {    
   UIBarButtonItem *done =    [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(leaveEditMode)] autorelease];    
   self.navigationItem.rightBarButtonItem = done;        
}    
- (void)textViewDidEndEditing:(UITextView *)textView {    
    self.navigationItem.rightBarButtonItem = nil;  
} 
- (void)leaveEditMode {
    [self.textView resignFirstResponder];   
} 

2）如果你的textview里不用回车键，可以把回车键当做退出键盘的响应键。

#pragma mark - UITextView Delegate Methods     
-(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{    
    if ([text isEqualToString:@"\n"]) {    
        [textView resignFirstResponder];    
        return NO;    
    }
    return YES;    
}

#pragma mark - 监听谈起退出两个通知,并且计算需要偏移的高度,然后动画偏移view
- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    //注册通知,监听键盘出现
    [[NSNotificationCenter defaultCenter]addObserver:self
                                            selector:@selector(handleKeyboardDidShow:)
                                                name:UIKeyboardDidShowNotification
                                              object:nil];
    //注册通知，监听键盘消失事件
    [[NSNotificationCenter defaultCenter]addObserver:self
                                            selector:@selector(handleKeyboardDidHidden:)
                                                name:UIKeyboardDidHideNotification
                                              object:nil];
}
#pragma mark - 键盘遮挡问题
- (void)handleKeyboardDidShow:(NSNotification*)paramNotification
{
    //获取键盘高度，在不同设备上，以及中英文下是不同的
    CGFloat kbHeight = [[paramNotification.userInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue].size.height;
    
    //计算出键盘顶端到inputTextView panel最大Y值(加上自定义的缓冲距离15),得到偏移量
    CGFloat offset = CGRectGetMaxX(self.groupManifestoTextView.frame) - (self.view.frame.size.height - kbHeight) + 15;
    
    // 取得键盘的动画时间，这样可以在视图上移的时候更连贯
    double duration = [[paramNotification.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    
    //将视图上移计算好的偏移
    if(offset > 0) {
        [UIView animateWithDuration:duration animations:^{
            self.view.frame = CGRectMake(0.0f, -offset, self.view.frame.size.width, self.view.frame.size.height);
        }];
    }
}
- (void)handleKeyboardDidHidden:(NSNotification*)paramNotification
{
    // 键盘动画时间
    double duration = [[paramNotification.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    
    //视图下沉恢复原状
    [UIView animateWithDuration:duration animations:^{
        self.view.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
    }];
}

- (void)viewDidDisappear:(BOOL)animated
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}