UITextView 边框的颜色，线宽，弧度，设置
导入QuartzCote框架：
#import <QuartzCore/QuartzCore.h>
设置边框：
textView.layer.borderColor = [UIColorgrayColor].CGColor;
textView.layer.borderWidth =1.0;
textView.layer.cornerRadius =5.0
#import <QuartzCore/QuartzCore.h>
textView.layer.borderColor = [UIColorgrayColor].CGColor;
textView.layer.borderWidth =1.0;
textView.layer.cornerRadius =5.0
