每個部分中選擇的項目數

Question

在下面的實現中，我可以跟蹤每個選定單元格的indexPath和項目總數選擇整個tableView。

我想知道我怎麼能夠得到每一節中選擇的項目數？

- (void)selectedItem: (UITableView *)tableView { 
    NSArray <NSIndexPath*> *selectedIndexPaths = [tableView indexPathsForSelectedRows]; 
    for (NSIndexPath *indexpath in selectedIndexPaths) { 
     NSLog(@"Section index : %ld", indexpath.section); 
     NSLog(@"Row index : %ld", indexpath.row); 
    } 
} 

這裏是打印輸出，你可以看到，我選擇在第0 2項，並在第1項1.

po [tableView indexPathsForSelectedRows] 
<__NSArrayI 0x1744428b0>(
<NSIndexPath: 0xc000000000400016> {length = 2, path = 0 - 2}, 
<NSIndexPath: 0xc000000000c00016> {length = 2, path = 0 - 6}, 
<NSIndexPath: 0xc000000001000116> {length = 2, path = 1 - 8} 
) 

Answer 1

NSMutableDictionary *selectedRowsInSectionDictionary = [NSMutableDictionary dictionary]; 
NSArray <NSIndexPath*> *selectedIndexPaths = [tableview indexPathsForSelectedRows]; 
for (NSIndexPath *indexpath in selectedIndexPaths) { 
    NSInteger numberOfSelectedRows = [[selectedRowsInSectionDictionary objectForKey: @(indexpath.section)] integerValue]; 
    numberOfSelectedRows++; 
    [selectedRowsInSectionDictionary setObject:@(numberOfSelectedRows) forKey: @(indexpath.section)]; 
} 

您將得到一個選擇的行數部分編號作爲鍵和該部分上選定行的數量作爲selectedRowsInSectionDictionary字典中的值。