如图：我想让它开始在最上面显示，而不是现在这个样子。

Question

iOS UITextView文本怎样居上显示而不是默认的居中?

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Answer 1

只需要初始化UITextView之后用KVO监听 "contentSize" 属性即可_textView = [[UITextView alloc] initWithFrame:CGRectMake(20.0f, DOT_COORDINATE, 260.0f,TABLE_VIEW_ROW_HEIGHT*2)];_textView.delegate = self;_textView.text = PROMPT_TEXT;_textView.font = [UIFont systemFontOfSize:18.0f];_textView.textColor = [UIColor lightGrayColor];[self.contentView addSubview:_textView];[_textView addObserver:self forKeyPath:@"contentSize" options:(NSKeyValueObservingOptionNew) context:NULL];#pragma mark - KVO-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary*)change context:(void *)context{UITextView *tv = object;// Center vertical alignmentCGFloat topCorrect = ([tv bounds].size.height - [tv contentSize].height * [tv zoomScale])/2.0;topCorrect = ( topCorrect < 0.0 ? 0.0 : topCorrect );tv.contentOffset = (CGPoint){.x = 0, .y = -topCorrect};// // Bottom vertical alignment// CGFloat topCorrect = ([tv bounds].size.height - [tv contentSize].height);// topCorrect = (topCorrect <0.0 ? 0.0 : topCorrect);// tv.contentOffset = (CGPoint){.x = 0, .y = -topCorrect};}

Answer 2

代码如下：//注册 监听text属性的事件&nbsp;[myTextView addObserver:selfforKeyPath:@"contentSize"options:NSKeyValueObservingOptionNewcontext:nil];//也可以监听contentSize属性//接收处理- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context&nbsp;{&nbsp; UITextView *mTrasView = object;CGFloat topCorrect = ([mTextbounds].size.height - [mTextcontentSize].height);&nbsp; &nbsp; topCorrect = (topCorrect <0.0 ?0.0 : topCorrect);&nbsp;&nbsp;&nbsp; &nbsp; mText.contentOffset = (CGPoint){.x =0, .y = -topCorrect/2};}当然，别忘了先设置一下水平居中属性。////如何做到输入时动态改变：也许可以在- (void)textViewDidChange:(UITextView *)textView；进行上述的偏移处理，同时可以加上动画效果，以便达到UITextFiled，居中输入的动态效果，此处只提供一个思路，其方法进行过验证，可行。但细节上需要你自己根据情况改变。