iOS 常见操作

1.截屏

- (void)captureImageFromView:(MorphingLabel *)sender{

CGRect screenRect = [self bounds];

//        UIGraphicsBeginImageContext(screenRect.size);

UIGraphicsBeginImageContextWithOptions(screenRect.size, NO, [UIScreen mainScreen].scale);

CGContextRef ctx = UIGraphicsGetCurrentContext();

[self.layer renderInContext:ctx];

UIImage *sendImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

//  [self.gifArr addObject:sendImage];

}

2.单元格高度适配

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {

// 获取每一行需要显示的内容

NSString *text = self.dataArray[indexPath.row];

// 方法弃用。推荐使用的新方法，功能肯定是想通的，配置的参数也有类比性

//    CGSize size = [text sizeWithFont:[UIFont systemFontOfSize:15] constrainedToSize:CGSizeMake(300, 9999)];

NSDictionary *attributes = @{NSFontAttributeName : [UIFont systemFontOfSize:15]};

/**

*  计算字符串的绘制范围

*

*  参数1  size  :  最大允许的范围

*  参数2  options :  计算多行文本，NSStringDrawingUsesLineFragmentOrigin

*  参数3 attributes :  字符串属性字典

*  参数4 context  :  绘制的上下文，当前上下文 nil

*

*  @return 计算后的大小

*/

CGRect rect = [text boundingRectWithSize:CGSizeMake(300, 9999) options:NSStringDrawingUsesLineFragmentOrigin attributes:attributes context:nil];

return rect.size.height + 5;

}

3.系统分享

-(void)share:(UIButton *)button {

NSMutableArray *activityItems = [[NSMutableArray alloc] init];

//可添加图片 标题 url

[activityItems addObject:getData];

// 服务类型控制器

UIActivityViewController *activityViewController =

[[UIActivityViewController alloc] initWithActivityItems:activityItems applicationActivities:nil];

[self presentViewController:activityViewController animated:YES completion:nil];

}