Objective c - 如何在数组中添加复选框的选中/未选中值

Question

如果选中复选框，我想保存值 TRUE，如果在数组中未选中，我想保存值 FALSE，我该怎么做。我已经在 tableview 中实现了复选框。代码是，

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    BOOL checked = [[checkedArr objectAtIndex:indexPath.row] boolValue];
    [checkedArr removeObjectAtIndex:indexPath.row];
    [cheval insertObject:(checked) ? @"FALSE":@"TRUE" atIndex:indexPath.row];
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    UIButton *button = (UIButton *)cell.accessoryView;
    UIImage *newImage = (checked) ? [UIImage imageNamed:@"tick.png"] : [UIImage imageNamed:@"white_bg.png"];
    [button setBackgroundImage:newImage forState:UIControlStateNormal];
    cell.accessoryView=button;
}

Answer 1

[cheval insertObject:(checked) ? @"FALSE":@"TRUE" atIndex:indexPath.row];

这当前将值的字符串表示形式添加到cheval 数组。您可以将其更改为：

[cheval insertObject:@(checked) atIndex:indexPath.row];

将字符串更改为NSNumber（这样您就可以调用boolValue）。

Answer 2

试试这个：

[array2 insertObject:[NSNumber numberWithBool:[checkButton state]] atIndex:indexPath.row];

checkButton 是复选框的出口。

Answer 3

1. NSMutableArray 不像 C 数组。它更像是一个列表。所以

   BOOL 已检查 = [[checkedArr objectAtIndex:indexPath.row] boolValue]; [checkedArr removeObjectAtIndex:indexPath.row];

不会像你想要的那样工作。

1. 如果cheval 包含的对象少于indexPath.row，[cheval insertObject:(checked) ? @"FALSE":@"TRUE" atIndex:indexPath.row]; 也会崩溃。

我建议使用NSMutableDictionary 而不是NSMutableArray。您可以使用NSIndexPath 对象作为键。并改变一点算法：

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSIndexPath *indexPathKey = [NSIndexPath indexPathForRow:indexPath.row inSection:indexPath.section]; // we use this code because in iOS 7 indexPath has type UIMutableIndexPath
    BOOL checked = ![checkedDict[indexPathKey] boolValue];
    checkedDict[indexPathKey] = @(checked);
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    UIButton *button = (UIButton *)cell.accessoryView;
    UIImage *newImage = (checked) ? [UIImage imageNamed:@"tick.png"] : [UIImage imageNamed:@"white_bg.png"];
    [button setBackgroundImage:newImage forState:UIControlStateNormal];
    cell.accessoryView=button;
}

另外你为什么不使用默认复选标记。如果您使用它，您应该按以下方式更改您的代码：

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSIndexPath *indexPathKey = [NSIndexPath indexPathForRow:indexPath.row inSection:indexPath.section]; // we use this code because in iOS 7 indexPath has type UIMutableIndexPath
    BOOL checked = ![checkedDict[indexPathKey] boolValue];
    checkedDict[indexPathKey] = @(checked);
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    cell.accessoryType = checked ? UITableViewCellAccessoryCheckmark : UITableViewCellAccessoryNone;
}