监听键盘工作,避免挡住文字输入

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    // Do any additional setup after loading the view, typically from a nib. 
    self.textView=[[UITextView alloc]initWithFrame:self.view.frame]; 
    self.textView.text=@"请输入文字"; 
    [self.view addSubview:self.textView]; 
} 
 
- (void)didReceiveMemoryWarning 
{ 
    [super didReceiveMemoryWarning]; 
    // Dispose of any resources that can be recreated. 
} 
 
- (void)viewWillAppear:(BOOL)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]; 
    [super viewWillAppear:YES]; 
} 
 
//监听事件 
- (void)handleKeyboardDidShow:(NSNotification*)paramNotification 
{ 
    //获取键盘高度 
    NSValue *keyboardRectAsObject=[[paramNotification userInfo]objectForKey:UIKeyboardFrameEndUserInfoKey]; 
     
    CGRect keyboardRect; 
    [keyboardRectAsObject getValue:&keyboardRect]; 
     
    self.textView.contentInset=UIEdgeInsetsMake(0, 0,keyboardRect.size.height, 0); 
} 
 
- (void)handleKeyboardDidHidden 
{ 
    self.textView.contentInset=UIEdgeInsetsZero; 
} 
 
- (void)viewDidDisappear:(BOOL)animated 
{ 
    [[NSNotificationCenter defaultCenter] removeObserver:self]; 
}