当我滚动UITableViewCell时，在iOS中选择的图像改变之前

Question

我需要实现这个功能。请帮帮我。在"unblockbtnClick"之后，点击改变图像，没问题，但是当滚动tableview时，选中的图像都变成了之前的图像。

这是我的代码。

  // Customize the appearance of table view cells.
    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    {

        static NSString *cellIdentifier = @"BlockedCell";

        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
        if(cell == nil)
        {
            NSArray *nib;
                nib = [[NSBundle mainBundle] loadNibNamed:@"BlockedCell" owner:self options:nil];
             cell = [nib objectAtIndex:0];

        }
        [btn_tblvcAddbtn addTarget:self action:@selector(unblockbtnClick:) forControlEvents:UIControlEventTouchUpInside];
        [btn_tblvcAddbtn setTag:indexPath.row];
            return cell;
    }
    -(IBAction)unblockbtnClick:(UIButton *)sender{
        NSLog(@"Value of selected button = %ld",(long)[sender tag]);
        [sender setBackgroundImage:[UIImage imageNamed:@"remove.png"] forState:UIControlStateNormal];
    }

Answer 1

您需要在if条件之外分配nib文件

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
    if(cell == nil)
    {
        // initialize cell here
    }
   NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"BlockedCell" owner:self options:nil];
   cell = [nib objectAtIndex:0];

Answer 2

-(IBAction)unblockbtnClick:(id)sender
{
    UIButton *btn=(UIButton *)sender;
    UITableViewCell *cellll;
    if([[[UIDevice currentDevice] systemVersion] intValue]<6)
        cellll=(UITableViewCell *)[btn superview];
    else
        cellll=(UITableViewCell *)[[btn superview]superview];

    NSIndexPath *aaa=[tblOption indexPathForCell:cellll];

    if([ArrSelectedData containsObject:[TblDataArrr objectAtIndex:aaa.row]])
    {
//tblDataArr is table dataArray  && ArrSelectedData is a array which contain selected itme of table 
        [ArrSelectedData removeObject:[TblDataArrr objectAtIndex:aaa.row]];
        [btn setBackgroundImage:[UIImage imageNamed:@"blank_checkbox.png"] forState:UIControlStateNormal];
    }
    else
    {
      [ArrSelectedData addObject:[TblDataArrr objectAtIndex:aaa.row]];
        [btn setBackgroundImage:[UIImage imageNamed:@"tick_checkbox.png"] forState:UIControlStateNormal];
    }
}

和cellForRowAtIndexPath

{
 if([ArrSelectedData containsObject:[TblDataArrr objectAtIndex:indexPath.row]])
          [tempBtn setBackgroundImage:[UIImage imageNamed:@"tick_checkbox.png"] forState:UIControlStateNormal];
    else
        [tempBtn setBackgroundImage:[UIImage imageNamed:@"blank_checkbox.png"] forState:UIControlStateNormal];
}

Answer 3

当你滚动一个单元格出屏幕，然后返回- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath方法被调用。你没有设置背景，这就是它被重置的原因。

要修复，您需要存储有关选定单元格的信息，并在- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath中检查它，并相应地应用适当的背景