在我的UITableView中,我有一个特定的单元格(A),其外观取决于同一部分中所有其他单元格的顺序.因此,每当用户将单元格拖动到表视图中的新位置时,我需要更新单元格(A)的内容.
在我看来,最好的方法是在一个方法中调用reloadRowsAtIndexPath:@ [indexPathOfCellA],该方法在完成表格视图重新排序后调用,类似于didMoveRowFromIndexPath:toIndexPath:.不幸的是,没有这样的方法.
因此我尝试在moveRowFromIndexPath:toIndexPath:方法的末尾调用reloadRowsAtIndexPath:@ [indexPathOfCellA]:
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath {
NSString *element = [self.dataSource objectAtIndex:sourceIndexPath.row];
[self.dataSource removeObjectAtIndex:sourceIndexPath.row];
[self.dataSource insertObject:element atIndex:destinationIndexPath.row];
[self updateInfoCellInTableView:tableView];
}
用相应的方法:
- (void)updateExampleCellInTableView:(UITableView *)tableView {
UInt32 infoCellRow = [tableView numberOfRowsInSection:0] - 1;
NSIndexPath *indexPathForInfoCell = [NSIndexPath indexPathForRow:infoCellRow inSection:0];
[tableView reloadRowsAtIndexPaths:@[indexPathForInfoCell] withRowAnimation:UITableViewRowAnimationAutomatic];
}
这不能正常工作.
当将单元格(A)拖动到新位置(B)时,该位置(B)处的旧单元格首先向上或向下移动以便为单元格(A)腾出空间.但当我抬起手指确认重新排序的细胞(B)移回其原始位置(B)时,两个细胞重叠. (我可以看到,因为细胞的背景是半透明的.)
我的假设是不允许从moveRowAtIndexPath:toIndexPath:中调用reloadRowsAtIndexPath:.但是,我在Apple的Developer Docs中找不到这样的规则.
这个假设是否正确?重新排序表视图后如何更新特定单元格?
最佳答案 我已经研究过这个,这是一个简单的例子.请仔细阅读一次.它可能会帮助你.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
tblData=[[UITableView alloc]init];
[tblData setDataSource:self];
[tblData setDelegate:self];
[tblData setFrame:CGRectMake(0, 75, 320, 430)];
[self.view addSubview:tblData];
[tblData setEditing:YES animated:NO];
mutArr=[[NSMutableArray alloc]init];
[mutArr addObject:@"Object 1"];
[mutArr addObject:@"Object 2"];
[mutArr addObject:@"Object 3"];
[mutArr addObject:@"Object 4"];
[mutArr addObject:@"Object 5"];
[mutArr addObject:@"Object 6"];
[mutArr addObject:@"Object 7"];
[mutArr addObject:@"Object 8"];
[mutArr addObject:@"Object 9"];
[mutArr addObject:@"Object 10"];
}
-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return mutArr.count;
}
-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell=[[UITableViewCell alloc]init];
cell.textLabel.text=[mutArr objectAtIndex:indexPath.row];
return cell;
}
- (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath
{
return YES;
}
- (void)tableView:(UITableView *)tableView moveRowAtIndexPath:(NSIndexPath *)sourceIndexPath toIndexPath:(NSIndexPath *)destinationIndexPath
{
NSString *element = [mutArr objectAtIndex:sourceIndexPath.row];
[mutArr removeObjectAtIndex:sourceIndexPath.row];
[mutArr insertObject:element atIndex:destinationIndexPath.row];
}
- (void)tableView:(UITableView *)tableView willBeginReorderingRowAtIndexPath:(NSIndexPath *)indexPath
{
previousPosition=(int)indexPath.row;
}
- (void)tableView:(UITableView *)tableView didEndReorderingRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell=[tableView cellForRowAtIndexPath:indexPath];
cell.textLabel.text=[NSString stringWithFormat:@"This cell moved from :%d to :%ld position",previousPosition,(long)indexPath.row];
}
这里“previousPosition”是一个整数,它被声明为全局变量.