iOS软键盘遮挡UITableView内文本框问题

1、注册
UIKeyboardDidShowNotification/UIKeyboardDidHideNotification通知。

-(id) initWithNibName:(NSString*)nibNameOrNil bundle:nibBundleOrNil {
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {

        // 写在这里，或者viewDidLoad
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardShown:) name:UIKeyboardDidShowNotification object:nil];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardHidden:) name:UIKeyboardDidHideNotification object:nil];
    }
    return self;
}
 
-(void) dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardDidHideNotification object:nil];
}

2、当通知到来，调整frame。

-(void) keyboardShown:(NSNotification*) notification {
    _initialTVHeight = _tableView.frame.size.height;
 
    CGRect initialFrame = [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    CGRect convertedFrame = [self.view convertRect:initialFrame fromView:nil];
    CGRect tvFrame = _tableView.frame;
    tvFrame.size.height = convertedFrame.origin.y;
    _tableView.frame = tvFrame;
}
 
-(void) keyboardHidden:(NSNotification*) notification {
    CGRect tvFrame = _tableView.frame;
    tvFrame.size.height = _initialTVHeight;
    [UIView beginAnimations:@"TableViewDown" context:NULL];
    [UIView setAnimationDuration:0.3f];
    _tableView.frame = tvFrame;
    [UIView commitAnimations];
}

3、触发文本框，滚动tableView

-(void) textFieldDidBeginEditing:(UITextField *)textField {
    NSIndexPath* path = [NSIndexPath indexPathForRow:row inSection:section];
    [self performSelector:@selector(scrollToCell:) withObject:path afterDelay:0.5f];
}
-(void) scrollToCell:(NSIndexPath*) path {
    [_tableView scrollToRowAtIndexPath:path atScrollPosition:UITableViewScrollPositionNone animated:YES];
}

4、苹果给的解决方案是这样的：
https://developer.apple.com/library/prerelease/ios/documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/KeyboardManagement/KeyboardManagement.html

demo 下载链接：
http://git.oschina.net/changyou/MyScrollViewKeyBoardDemo/repository/archive/master

5、或许这个更好

- (void)viewDidLoad {

//  监听键盘的通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillChangeFrameNotification:) name:UIKeyboardWillChangeFrameNotification object:nil];
 
 }

#pragma mark - 键盘通知回调方法
/*
UIKeyboardAnimationCurveUserInfoKey = 7;   键盘执行动画的节奏
UIKeyboardAnimationDurationUserInfoKey = "0.25"; 键盘弹出动画执行时间
UIKeyboardBoundsUserInfoKey = "NSRect: {{0, 0}, {375, 258}}"; 键盘尺寸
UIKeyboardCenterBeginUserInfoKey = "NSPoint: {187.5, 796}"; 键盘当前的位置
UIKeyboardCenterEndUserInfoKey = "NSPoint: {187.5, 538}";  键盘改变后中心的位置
UIKeyboardFrameBeginUserInfoKey = "NSRect: {{0, 667}, {375, 258}}"; 键盘当前的frame
UIKeyboardFrameEndUserInfoKey = "NSRect: {{0, 409}, {375, 258}}"; 键盘改变后的frame
*/
- (void)keyboardWillChangeFrameNotification:(NSNotification *) notification
{
//    NSLog(@"%@",notification.userInfo);
//  1.取出键盘当前的y坐标
   CGRect beginFrame =  [notification.userInfo[UIKeyboardFrameBeginUserInfoKey] CGRectValue];
   CGRect endFrame =  [notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
//  2.中间的差值
   CGFloat minus =  endFrame.origin.y - beginFrame.origin.y ;
//  3.根据差值改变控制器view的frame
   CGRect viewFrame = self.view.frame;
   viewFrame.origin.y += minus;
   self.view.frame = viewFrame;
   
}

/**
*  拖拽tableView方法
*/
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
//  退出键盘
   [self.view endEditing:YES];
}

#pragma mark -dealloc方法写到最后
- (void)dealloc
{
//  移除通知
    [[NSNotificationCenter defaultCenter] removeObserver:self];
    
}

6、更简单实用的在这里：
http://www.jianshu.com/p/9115c2c986c9

参考：

1. http://blog.seancarpenter.net/2012/10/15/scrolling-a-uitableview-when-displaying-the-keyboard/

2. Managing Text Fields and Text Views