iOS企业级开发实用技术

UITextView 字体垂直居中水平居中显示

2016-03-03  本文已影响6126人  代码干货

<pre>

import <UIKit/UIKit.h>

@interface TMVerticallyCenteredTextView : UITextView

@end
</pre>

<pre>

import "TMVerticallyCenteredTextView.h"

@interface TMVerticallyCenteredTextView()
@end
@implementation TMVerticallyCenteredTextView

-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
if ([keyPath isEqualToString:@"contentSize"])
{
UITextView *tv = object;
CGFloat deadSpace = ([tv bounds].size.height - [tv contentSize].height);
CGFloat inset = MAX(0, deadSpace/2.0);
tv.contentInset = UIEdgeInsetsMake(inset, tv.contentInset.left, inset, tv.contentInset.right);
}
}

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