UITextView 动画视图后内容偏移不良

我有一个 UITextView 位于视图底部。当用户点击它时，我需要将视图动画放大 150 像素。我在用着：

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

and

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

来做这个。

在iOS5上，它运行良好。但在 iOS 4.3 上，当视图动画化时，此 UITextView 中的内容会向上移动几个像素。

截屏：http://cl.ly/1q3e0W2G1M000u1U3w1f http://cl.ly/1q3e0W2G1M000u1U3w1f

有人遇到类似问题吗？

Code:

- (void)textViewDidBeginEditing:(UITextView *)textView{
    if([textView.text isEqualToString:@"Placeholder text"]){
        textView.text = @"";
    }

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDuration:0.3];
    [UIView setAnimationBeginsFromCurrentState:YES];
    self.view.frame = CGRectMake(self.view.frame.origin.x, (self.view.frame.origin.y - 150.0), self.view.frame.size.width, self.view.frame.size.height);
    [UIView commitAnimations];
}

- (void)textViewDidEndEditing:(UITextView *)textView{
    if([textView.text isEqualToString:@""]){
        textView.text = @"Placeholder text";
    }

    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDelegate:self];
    [UIView setAnimationDuration:0.3];
    [UIView setAnimationBeginsFromCurrentState:YES];
    self.view.frame = CGRectMake(self.view.frame.origin.x, (self.view.frame.origin.y + 150.0), self.view.frame.size.width, self.view.frame.size.height);
    [UIView commitAnimations];    
}

当 textView 中的调用方法开始编辑方法以及动画完成后，您需要重置文本视图的内容插入...

试试这个代码：

- (void)textViewDidBeginEditing:(UITextView *)textView{
   [textView setContentInset:UIEdgeInsetsMake(0, 0, 0, 0)];
}