ios - 如何使 uitableview 的部分标题中的按钮保持选中状态

Question

我有一个按钮，如果它被选中，我想更改背景图像。我这里的代码有效，但如果我再次向上和向下滚动，它将变为未选中状态。

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
    UIView *sectionHeader = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.tableView.frame.size.width, 33)];
    UILabel *sectionHeaderLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 0, 100, 30)];
    sectionHeaderLabel.text = [NSString stringWithFormat:@"Section %i",section+1];
    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(200, 5, 42, 20)];
    [button setBackgroundImage:[UIImage imageNamed:@"unselected_image"] forState:UIControlStateNormal];
    [button setBackgroundImage:[UIImage imageNamed:@"selected_image"] forState:UIControlStateSelected];
    [button addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
    [sectionHeader addSubview:button];
    return sectionHeader;
}

- (void)buttonPressed:(id)sender {
    UIButton *allButton = (UIButton*)sender;
    allButton.selected = !allButton.selected;
}

Answer 1

1) 在您的 ViewDidLoad 中创建一个图像名称数组。该数组会跟踪您照片的名称，无论照片是否被点击。

- (void)viewDidLoad
{
    //this array is just an example, loop and add items to the array for the number of sections you want
    //in this example there are 5 sections with 5 images
    imageNameArray = [[NSMutableArray alloc] initWithObjects:@"unselected_image", @"unselected_image", @"unselected_image", @"unselected_image", @"unselected_image", nil];
}

2) 你的viewForHeaderInSection

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
    UIView *sectionHeader = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.tableView.frame.size.width, 33)];
    UILabel *sectionHeaderLabel = [[UILabel alloc] initWithFrame:CGRectMake(10, 0, 100, 30)];
    sectionHeaderLabel.text = [NSString stringWithFormat:@"Section %i",section+1];
    button = [[UIButton alloc] initWithFrame:CGRectMake(200, 5, 42, 20)];
    [button setBackgroundImage:[UIImage imageNamed:[imageNameArray objectAtIndex:section]] forState:UIControlStateNormal];
    [button setTag:section];
    [button addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
    [sectionHeader addSubview:button];
    return sectionHeader;
}

3) 如果按下按钮，更改数组中图像的名称

- (void)buttonPressed:(id)sender
{
    UIButton *allButton = (UIButton*)sender;

    [imageNameArray insertObject:@"selected_image" atIndex:[allButton tag]];
    [allButton setBackgroundImage:[UIImage imageNamed:[imageNameArray objectAtIndex:[allButton tag]]] forState:UIControlStateNormal];
}