iOS开发遇到的小问题 (未完待续......)

• tablview点击push到下一个页面，pop出来时位置下移了 ，解决办法:

self.automaticallyAdjustsScrollViewInsets = NO;

• 取消tableview点击时的灰色效果

cell.selectionStyle = UITableViewCellSelectionStyleNone;

• 隐藏tabelview的分割线

[self.tableView setSeparatorStyle:UITableViewCellSeparatorStyleNone];

• tableview分割线从头开始

_tableView.separatorInset = UIEdgeInsetsZero;

• tableview取消区头停滞效果

-(void)scrollViewDidScroll:(UIScrollView *)scrollView {
    
    CGFloat sectionHeaderHeight = sectionHead.height;
    if (scrollView.contentOffset.y<=sectionHeaderHeight&&scrollView;.contentOffset.y>=0)
    {
        scrollView.contentInset = UIEdgeInsetsMake(-scrollView.contentOffset.y, 0, 0, 0);
    }
    else if(scrollView.contentOffset.y>=sectionHeaderHeight)
    {
        scrollView.contentInset = UIEdgeInsetsMake(-sectionHeaderHeight, 0, 0, 0);
    }
}

• 防止scrollView手势和侧滑手势冲突

[scrollView.panGestureRecognizerrequireGestureRecognizerToFail:self.navigationController.interactivePopGestureRecognizer];

• ScrollView不能划到viewController顶部

self.automaticallyAdjustsScrollViewInsets = NO;

• 滑动隐藏navigationbar

self.navigationController.hidesBarsOnSwipe=YES;

• label设置首行缩进

label.attributedText = [self setLabelIndent:15 text:@"这里是内容"];
// indent是字体的大小， text是内容
-(NSAttributedString *)setLabelIndent:(CGFloat)indent text:(NSString *)text {
    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
    paragraphStyle.firstLineHeadIndent = indent * 2;
    NSDictionary *attributeDic = @{NSParagraphStyleAttributeName : paragraphStyle};
    NSAttributedString *attrText = [[NSAttributedString alloc] initWithString:text attributes:attributeDic];
    
    return attrText;
}

• 取消btn点击高亮状态，解决办法:

_btn.adjustsImageWhenHighlighted = NO;

• iOS系统 POP 手势与 UIScrollView 手势冲突的解决方法

新建一个 ScrollView 继承 UIScrollView

重写 gestureRecognizer:(UIGestureRecognizer)gestureRecognizer  shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer)otherGestureRecognizer

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
   // 判断 otherGestureRecognizer 是不是系统 POP 手势
   if ([otherGestureRecognizer.view isKindOfClass:NSClassFromString(@"UILayoutContainerView")]) {

       // 判断 POP 手势的状态是 begin 还是 fail，同时判断 scrollView 的 ContentOffset.x 是不是在最左边
       if (otherGestureRecognizer.state == UIGestureRecognizerStateBegan && self.contentOffset.x == 0) {
           return YES;
       }
   }
   return NO;
}

• UIImagePickerController拍照之后图片旋转的问题 ，解决办法:

// 拍照选择照片协议方法
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    
    NSString *type = [info objectForKey:UIImagePickerControllerMediaType];
    if ([type isEqualToString:@"public.image"]) {
        UIImage *image=[info objectForKey:UIImagePickerControllerOriginalImage];
        UIImageOrientation imageOrientation=image.imageOrientation;
        if(imageOrientation!=UIImageOrientationUp)
            {
            UIGraphicsBeginImageContext(image.size);
            [image drawInRect:CGRectMake(0, 0, image.size.width, image.size.height)];
            image = UIGraphicsGetImageFromCurrentImageContext();
            UIGraphicsEndImageContext();
            }
    }
}