objective-c - 如何增加 NSIndexPath

Question

我有一种数据情况，我想使用索引路径。当我遍历数据时，我想增加 NSIndexPath 的最后一个节点。我到目前为止的代码是：

int nbrIndex = [indexPath length];
NSUInteger *indexArray = (NSUInteger *)calloc(sizeof(NSUInteger),nbrIndex);
[indexPath getIndexes:indexArray];
indexArray[nbrIndex - 1]++;
[indexPath release];
indexPath = [[NSIndexPath alloc] initWithIndexes:indexArray length:nbrIndex];
free(indexArray);

这感觉有点笨拙-有更好的方法吗？

Answer 1

你可以试试这个——也许同样笨重，但至少短一点：

NSInteger newLast = [indexPath indexAtPosition:indexPath.length-1]+1;
indexPath = [[indexPath indexPathByRemovingLastIndex] indexPathByAddingIndex:newLast];

Answer 2

这样少一行：

indexPath = [NSIndexPath indexPathForRow:indexPath.row+1 inSection:actualIndexPath.section];

Answer 3

检查我在 Swift 上的解决方案：

func incrementIndexPath(indexPath: NSIndexPath) -> NSIndexPath? {
    var nextIndexPath: NSIndexPath?
    let rowCount = numberOfRowsInSection(indexPath.section)
    let nextRow = indexPath.row + 1
    let currentSection = indexPath.section

    if nextRow < rowCount {
        nextIndexPath = NSIndexPath(forRow: nextRow, inSection: currentSection)
    }
    else {
        let nextSection = currentSection + 1
        if nextSection < numberOfSections {
            nextIndexPath = NSIndexPath(forRow: 0, inSection: nextSection)
        }
    }

    return nextIndexPath
}

Answer 4

Swift 4 中的 for 循环使用嵌入式 UITableView 实现了类似的结果，遍历 for 循环，用“Row Updated”填充单元格的详细文本

for i in 0 ..< 9 {
     let nextRow = (indexPath?.row)! + i
     let currentSection = indexPath?.section
     let nextIndexPath = NSIndexPath(row: nextRow, section: currentSection!)

     embeddedViewController.tableView.cellForRow(at: nextIndexPath as IndexPath)?.detailTextLabel?.text = "Row Updated"

     let myTV = embeddedViewController.tableView
     myTV?.cellForRow(at: nextIndexPath as IndexPath)?.backgroundColor = UIColor.red
     myTV?.deselectRow(at: nextIndexPath as IndexPath, animated: true)                            
}