将 NSString 转换为 NSIndexPath答案

【问题标题】：Convert NSString to NSIndexPath将 NSString 转换为 NSIndexPath
【发布时间】：2013-12-27 21:45:49
【问题描述】：

基本上我想做的是将 NSString 转换为 NSIndexPath。当我使用 S3 获取对象时，我需要使用 requestTag 属性，该属性采用 NSString。我使用这个标签来确定哪个对象已经完成下载，从而确定哪个活动指示器停止旋转。下面是部分代码。如何将 NSString requestTag 转换为 NSIndexPath？

- (void)tableView:(UITableView *) tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
[tableView deselectRowAtIndexPath:indexPath animated:YES];
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];

UIActivityIndicatorView *activityView = (UIActivityIndicatorView *)[cell viewWithTag:103];

if (![self.activityIndictatorOn containsObject:indexPath]) {
    [self.activityIndictatorOn addObject:indexPath];
    [activityView startAnimating];

...
    getObjectRequest.requestTag = [NSString stringWithFormat:@"%@", indexPath];
}



-(void)request:(AmazonServiceRequest *)request didCompleteWithResponse:(AmazonServiceResponse *)response
{

NSLog(@"DOWNLOAD COMPLETE");


[self stopActivityIndicator:request.requestTag];
[self.downloadFinished addObject:request.requestTag];
}



 -(void)stopActivityIndicator:(NSString *)rowAtIndexPath
{
//Need to convert rowAtIndexPath to NSIndexPath
//Following line results in warning
UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:rowAtIndexPath];
UIActivityIndicatorView *activityView = (UIActivityIndicatorView *)[cell viewWithTag:103];
[activityView stopAnimating];
 }

【问题讨论】：

标签： ios objective-c amazon-web-services type-conversion nsindexpath

【解决方案1】：

[NSString stringWithFormat:@"%@", indexPath]

使用description方法将索引路径转换为字符串形式

{length = 2, path = <section> - <row>}

这有点难以解析回索引路径。

因此我建议将索引路径转换为请求字符串格式为section:row 与

NSString *requestTag = [NSString stringWithFormat:@"%ld:%ld", (long)indexPath.section, (long)indexPath.row];

然后您可以轻松地将其转换回来

NSArray *tmp = [requestTag componentsSeparatedByString:@":"];
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:[tmp[1] integerValue] inSection:[tmp[0] integerValue]];

【讨论】：

【解决方案2】：

好吧，您可以将indexPath 转换为NSString 并设置为requestTag，如下所示：

     getObjectRequest.requestTag = [NSString stringWithFormat:@"%ld,%ld", indexPath.section, indexPath.row];

然后将其转换回NSIndexPath，如下所示：

    NSArray *rowIndexArray = [rowAtIndexPath componentsSeparatedByString:@","];
    NSIndexPath *indexPath = [NSIndexPath indexPathForItem:rowIndexArray[1] inSection:rowIndexArray[0]];

【讨论】：