1 图片拉伸

处理图片拉伸的方式有很多,以下参考了http://www.jianshu.com/p/80290e6ae9ac, http://www.jianshu.com/p/1110109f43f5
两篇文章的分享,总结如下,仅为自己使用方便.

1 代码方式

1.1 iOS 5.0之前

• (UIImage *)stretchableImageWithLeftCapWidth:(NSInteger)leftCapWidth topCapHeight:(NSInteger)topCapHeight;

 UIImage *image = [UIImage imageNamed:@"chat"];
    //  1 =  width - leftCapWidth - right
    //   1 =  height - topCapWidth - bottom
    UIImage *reszingImage = [image stretchableImageWithLeftCapWidth:image.size.width * 0.5 topCapHeight:image.size.height * 0.5];

 [self.btn setBackgroundImage: reszingImage forState:UIControlStateNormal];

1.2 iOS 5.0

• (UIImage *)resizableImageWithCapInsets:(UIEdgeInsets)capInsets;

// 默认是平铺
    UIImage *resizingImage = [image resizableImageWithCapInsets:UIEdgeInsetsMake(10, 10, 10, 10)];

1.3 iOS 6.0

• (UIImage *)resizableImageWithCapInsets:(UIEdgeInsets)capInsets resizingMode:(UIImageResizingMode)resizingMode;

 // 1.创建图片对象
    UIImage *image = [UIImage imageNamed:@"chat"];
    // 2.创建可拉伸的图片(告诉图片什么地方需要拉伸)
    CGFloat imageW = image.size.width;
    CGFloat imageH = image.size.height;

      /*UIImageResizingModeStretch：拉伸模式，通过拉伸UIEdgeInsets指定的矩形区域来填充图片
UIImageResizingModeTile：平铺模式，通过重复显示UIEdgeInsets指定的矩形区域来填充图片*/
    UIImage *resizingImage = [image resizableImageWithCapInsets:UIEdgeInsetsMake(imageH * 0.5, imageW * 0.5, imageH * 0.5 - 1, imageW * 0.5 - 1) resizingMode:UIImageResizingModeTile];

2 图形化方法

2.1 storyBoard中

2.2 assets中show slicing