IOS 创建一个可以随意拉伸不变形的图片

创建一个扩展 UIImage的类

#import "UIImage_Extension.h"

@implementation UIImage+Extension
/**
 *返回一张可以随意拉伸不变形的图片
 *
 */
+(UIImage *)resizableImage:(NSString *)name
{

    UIImage *normal=[UIImage imageNamed:name];
    CGFloat w=normal.size.width*0.5;
    CGFloat h=normal.size.height*0.5;
    return [normal resizableImageWithCapInsets:UIEdgeInsetsMake(h, w, h, w)];
}
@end

调用

   [self.textView setBackgroundImage:[UIImage resizableImage:@"chat_send_nor"] forState:UIControlStateNormal];