这适用于自定义按钮:

[UIView setAnimationsEnabled:NO];
[_button setTitle:@"title" forState:UIControlStateNormal];
[UIView setAnimationsEnabled:YES];

对于系统按钮，你需要在重新启用动画之前添加这个(谢谢@Klaas):

[_button layoutIfNeeded];

我发现这个解决方案与UIButtonTypeSystem一样，但只有当按钮出于某种原因被启用时才会工作。

[UIView setAnimationsEnabled:NO];
[_button setTitle:@"title" forState:UIControlStateNormal];
[UIView setAnimationsEnabled:YES];

因此，如果您需要在设置标题时禁用按钮，则必须添加这些。

[UIView setAnimationsEnabled:NO];
_button.enabled = YES;
[_button setTitle:@"title" forState:UIControlStateNormal];
_button.enabled = NO;
[UIView setAnimationsEnabled:YES];

(iOS 7, Xcode 5)

结合以上的答案，可以为UIButtonTypeSystem提供以下解决方案:

if (_button.enabled)
{
    [UIView setAnimationsEnabled:NO];
    [_button setTitle:@"title" forState:UIControlStateNormal];
    [UIView setAnimationsEnabled:YES];
}
else // disabled
{
    [UIView setAnimationsEnabled:NO];
    _button.enabled = YES;
    [_button setTitle:@"title" forState:UIControlStateNormal];
    _button.enabled = NO;
    [UIView setAnimationsEnabled:YES];
}

从iOS 7.1开始，唯一适合我的解决方案是用UIButtonTypeCustom类型初始化按钮。

所以我找到了可行的解决方案:

_logoutButton.titleLabel.text = NSLocalizedString(@"Logout",);
[_logoutButton setTitle:_logoutButton.titleLabel.text forState:UIControlStateNormal];

首先我们改变按钮的标题，然后调整这个标题的按钮大小

也许生成2个动画和2个按钮是一个更好的解决方案，以避免出现动画和更改按钮文本的问题?

我创建了第二个uibutton并生成了2个动画，这个解决方案没有hickup。

    _button2.hidden = TRUE;
    _button1.hidden = FALSE;

    CGPoint startLocation = CGPointMake(_button1.center.x, button1.center.y - 70);
    CGPoint stopLocation  = CGPointMake(_button2.center.x, button2.center.y- 70);


    [UIView animateWithDuration:0.3 animations:^{ _button2.center = stopLocation;} completion:^(BOOL finished){_button2.center = stopLocation;}];
    [UIView animateWithDuration:0.3 animations:^{ _button1.center = startLocation;} completion:^(BOOL finished){_button1.center = startLocation;}];