Oddiy UITableView-da "bo'sh" hujayralar ko'rinishini qanday o'zgartirishim mumkin?

Garchi bu siz qidirayotgan narsa bo'lmasa-da, jadvalda pastki ko'rinishni o'rnatish orqali uni bo'sh hududni (bo'sh hujayralar o'rniga) ko'rsatish uchun ham o'zgartirishingiz mumkin. 0 balandlikdagi UIView yordam beradi.

samvermette javobiga asoslanib, lekin UITableViewCell kichik sinfidagi tasvirni birlashtirish o‘rniga bevosita fon tasviridan foydalanish uchun o‘zgartirildi. Semning javobi yaxshi, lekin u to'g'ridan-to'g'ri fon tasvirini yaratishdan ko'ra kamroq samarali bo'ladi.

UIView kichik sinfini yarating -- bu misolda men uni CustomTiledView deb nomladim -- va sinfga quyidagi kodni qo'shing:

- (void)drawRect:(CGRect)rect {
UIImage *image = [UIImage imageNamed:@"tableview_empty_cell_image"];
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextScaleCTM (context, 1, -1); 
CGContextDrawTiledImage(context, 
                        CGRectMake(0, 0, rect.size.width, image.size.height), 
                        [image CGImage]); 
}

Tableviewcontroller-ga quyidagi kodni qo'shing:

- (CGFloat)tableView:(UITableView *)tableView 
           heightForFooterInSection:(NSInteger)section {
    // this can be any size, but it should be 1) multiple of the 
    // background image height so the last empty cell drawn
    // is not cut off, 2) tall enough that footer cells
    // cover the entire tableview height when the tableview
    // is empty, 3) tall enough that pulling up on an empty
    // tableview does not reveal the background.
        return BACKGROUND_IMAGE_HEIGHT * 9; // create 9 empty cells
}

- (UIView *)tableView:(UITableView *)tableView 
            viewForFooterInSection:(NSInteger)section {
    CustomTiledView *footerView = [[CustomTiledView alloc] init];
    return [footerView autorelease];
}

Nihoyat, jadval ko'rinishining pastki tarkibini -tableView:heightForFooterInsection: dan qaytarilgan qiymatning salbiyiga o'rnatishingiz kerak bo'ladi, bu misolda u -1*BACKGROUND_IMAGE_HEIGHT*9 bo'ladi. Pastki tarkibni Interface Builder o'lchami inspektoridan yoki tableviewcontrollerdan self.tableView.contentInset xususiyatini o'rnatish orqali o'rnatishingiz mumkin.

Salom!

Men tableView sarlavhasi va altbilgisi ko'rinishlariga ~300px balandlikdagi UIView pastki sinfini o'rnatdim, tableView qo'shimchalarini ushbu ko'rinishlarni qoplashi uchun sozladim (yuqori va pastki qo'shimchalarni -300px ga o'rnating).

Mening UIView kichik sinfim drawRect usulini qo'llaydi, unda men bo'sh UITableViewCell ni takroran chizish uchun CGContextDrawTiledImage() dan foydalanaman:

- (void)drawRect:(CGRect)rect {

    UIGraphicsBeginImageContextWithOptions(CGSizeMake(300, 46),NO,0.0);
    emptyCell = [[SWTableViewCell alloc] initWithFrame:CGRectZero];
    [emptyCell drawRect:CGRectMake(0, 0, 300, 46)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    [emptyCell release];
    UIGraphicsEndImageContext();

    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextScaleCTM (context, 1, -1); // this prevents the image from getting drawn upside-down
    CGContextDrawTiledImage(context, CGRectMake(0, 0, 300, 46), [newImage CGImage]);
}

Mening vaziyatimda jadval ko'rish hujayralari balandligi 46px, shuning uchun agar men UIView pastki sinfini ushbu bo'sh hujayralardan 8 tasini o'z ichiga olishini istasam, uni 368px balandlikda qilishim kerak.

http://jomnius.blogspot.com/2011/03/hide-uitableview-empty-cell-separator.html Jadvalda hujayra ajratuvchi qatorlar yoʻqligini aniqlashning oson usuli:

self.tableView.separatorStyle = UITableViewCellSeparatorStyleNone;

Agar sizga ajratuvchi chiziqlar kerak bo'lsa, qiyin yo'l, jadvalda ajratuvchi chiziqlar yo'qligini aniqlash va maxsus UITableViewCell-ning bir qismi sifatida hujayra ajratuvchi qatorlarni yaratishdir. Hujayraning pastki qismi, shubhasiz va juda nozik grafik tasvirdan foydalangan holda. Rasmning avtomatik o'lchamini va rejimini to'g'ri belgilashni unutmang.

Boshqa usul - bo'sh UITableView ning tableFooterView ni aniqlash:

UIView *footer =
    [[UIView alloc] initWithFrame:CGRectZero];
self.myTable.tableFooterView = footer;
[footer release];

Agar siz TableView-da umuman hujayralar bo'lmaganda "bo'sh hujayralar" balandligini o'zgartirmoqchi bo'lsangiz: UITableView-ning rowHeight xususiyatini o'rnatishingiz kerak (tableView:heightForRowAtIndexPath: ilovasi bo'sh TableViews-ga ta'sir qilmaydi). Agar TableView-da hujayralar mavjud bo'lsa va siz tableView:heightForRowAtIndexPath: ni amalga oshirgan bo'lsangiz, bo'sh hujayralar uchun oxirgi satr balandligi ishlatiladi.

Ehtimol, fonni bo'sh hujayralar ko'rinishi bilan to'ldiradigan UITableView ning maxsus pastki sinfini yaratishingiz kerak bo'ladi.

- (void)drawRect:(CGRect)rect {
  [super drawRect: rect];

  // draw your background here if the rect intersects with the background area
}

Ishonamanki, UITableView tableView:viewForFooterInSection: usulini qo'llash usuli jadval bo'sh, ya'ni kataklari bo'lmagan holatda ishlamaydi. Bunday holda, siz taklif qilingan Answerbot texnikasidan foydalanishingiz mumkin, bu esa yaratilgan UIView ni jadvalning pastki koʻrinishiga aniq kiritish uchun oʻzgartirilishi mumkin, quyidagi kabi:

    CGRect cellRect = CGRectMake(0, 0, table.bounds.size.width, table.bounds.size.height);
    CustomTiledView *footerView = [[[CustomTiledView alloc] initWithFrame:cellRect] autorelease];
    table.tableFooterView = footerView;

Swift 4.0 uchun:

self.tableView.tableFooterView = UIView(frame: CGRect.zero)