代码块随记

无奈有时记性不好，一些经常用的随记。

九宫格

    for (int x = 0; x < 10; x++) {
    //创建按钮
    int i = x / 3;   //---- 0 1 2   行
    int j = x % 3;   //-----0 1 2   列
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    btn.frame = CGRectMake(j * (BUTTONWIDTH + columnWidth) + columnWidth, i * (BUTTONHEIGHT + rowHeight) + rowHeight, BUTTONWIDTH, BUTTONHEIGHT);
    btn.tag = x + 1;
    [btn setTitle:[NSString stringWithFormat:@"%d",btn.tag] forState:UIControlStateNormal];
    [btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btn];
  }

裁剪图片

-(UIImage *)getImageFromImage:(UIImage*) superImage
{
    CGSize subImageSize = CGSizeMake(320, 200);
    //定义裁剪的区域相对于原图片的位置
    CGRect subImageRect = CGRectMake(0, 60, superImage.size.width, superImage.size.height);
    CGImageRef imageRef = superImage.CGImage;
    CGImageRef subImageRef = CGImageCreateWithImageInRect(imageRef, subImageRect);
    UIGraphicsBeginImageContext(subImageSize);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextDrawImage(context, subImageRect, subImageRef);
    UIImage* subImage = [UIImage imageWithCGImage:subImageRef];
    UIGraphicsEndImageContext();
    //返回裁剪的部分图像
    return subImage;
}  

//渲染缓存

self.layer.shouldRasterize=YES;
self.layer.rasterizationScale= [UIScreenmainScreen].scale;

//NSTextAttachment 调整centerY

NSTextAttachment * ment = [[NSTextAttachment alloc] initWithData:nil ofType:nil];
    ment.image = [];
    ment.bounds =  CGRectMake(0, self.Label.font.descender/2.0, self.Label.font.ascender, self.Label.font.ascender);

0.jpg