UIPicker中自定义UITableViewCell中的UITapGestureRecognizer无效

Question

我正在尝试使用UIPicker中的setAccessoryType和Suda's blog

中的UITableViewCell在UITapGestureRecognizer中实施多选选项

现在问题是： 没有收到任何错误，但toggleSelection:未被识别。 selectedItems未被调用（无法在#import <UIKit/UIKit.h> @interface ViewController : UIViewController<UIPickerViewDelegate, UIPickerViewDataSource> { NSMutableArray *selectedItems; NSArray *datasource; } @property (weak, nonatomic) IBOutlet UIPickerView *pickerView; @end 中添加/删除对象。）

  

我在SO中搜索过这个问题，但没有得到任何解决方案。没有什么对我有用。

我使用了以下代码

ViewController.h

- (void)viewDidLoad {
    [super viewDidLoad];
    datasource = [[NSArray alloc] initWithObjects:@"A", @"B", @"C", @"D", @"E", nil];
    self.pickerView.delegate = self;
    self.pickerView.dataSource = self;
    selectedItems = [[NSMutableArray alloc] init];
}

-(NSInteger) numberOfComponentsInPickerView:(UIPickerView *)pickerView {
    return 1;
}

-(NSInteger) pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
    return datasource.count;
}

-(NSString*) pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
    return datasource[row];
}

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view {
    UITableViewCell *cell = (UITableViewCell *)view;
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil];
        [cell setBackgroundColor:[UIColor clearColor]];
        [cell setBounds:CGRectMake(0, 0, cell.frame.size.width - 20, 44)];
        cell.tag = row;
        UITapGestureRecognizer * singleTapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(toggleSelection:)];
        singleTapGestureRecognizer.numberOfTapsRequired = 1;

        [cell setUserInteractionEnabled:YES];
        [cell addGestureRecognizer:singleTapGestureRecognizer];
        // Also tried with [cell.contentView addGestureRecognizer:singleTapGestureRecognizer];
    }
    if ([selectedItems indexOfObject:[NSNumber numberWithInt:row]] != NSNotFound) {
        [cell setAccessoryType:UITableViewCellAccessoryCheckmark];
    } else {
        [cell setAccessoryType:UITableViewCellAccessoryNone];
    }
    cell.textLabel.text = [datasource objectAtIndex:row];
    return cell;
}

- (void)toggleSelection:(UITapGestureRecognizer *)recognizer {
    NSNumber *row = [NSNumber numberWithInt:recognizer.view.tag];
    NSUInteger index = [selectedItems indexOfObject:row];
    if (index != NSNotFound) {
        [selectedItems removeObjectAtIndex:index];
        [(UITableViewCell *)(recognizer.view) setAccessoryType:UITableViewCellAccessoryNone];
    } else { 
        [selectedItems addObject:row];
        [(UITableViewCell *)(recognizer.view) setAccessoryType:UITableViewCellAccessoryCheckmark];
    }
}

ViewController.m

intellij

任何帮助都会很明显。