点击更改表格视图单元格的 UIImage

Question

可能是一个简单的修复。

我的表格视图控制器的每个单元格内都有一个图像，上面有一个点击手势识别器。这工作正常并且记录正确。

我需要将图像从其默认状态更改为在“选中”状态（绿色）和“取消选中”状态（红色）之间切换。换句话说，它是一个清单，一开始是灰色的，然后你点击图像，图像变成绿色复选标记，再次点击，它变成红色x。

这里有一个问题：当它只是 didSelectRowAtIndexPath 方法中的一个条件语句时，它可以工作，但是由于我添加了手势识别器并创建了 imageTapped 方法，我似乎无法翻译它。因此，this 等其他有用的线程对我不起作用。

一如既往的感谢。你们是最棒的。

代码如下：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"PlacesCell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:@"PlacesCell"];
        cell.selectionStyle = UITableViewCellSelectionStyleNone;
    }

    //Create ImageView
    cell.imageView.image = [UIImage imageNamed:@"checkmark.png"];

    //Add Gesture Recognizer
    UITapGestureRecognizer *tapped = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imageTapped)];
    tapped.numberOfTapsRequired = 1;
    [cell.imageView addGestureRecognizer:tapped];
    cell.imageView.userInteractionEnabled = YES;
    [cell addSubview:cell.imageView];

    return cell;

    }

//Method controlling what happens when cell's UIImage is tapped
-(void)imageTapped
{

    UITableViewCell *cell;

    UIImage *imageDefault = [UIImage imageNamed:@"checkmark.png"];
    UIImage *imageRed = [UIImage imageNamed:@"checkmark(red).png"];
    UIImage *imageGreen = [UIImage imageNamed:@"checkmark(green).png"];

    if (cell.imageView.image == imageDefault) {
        cell.imageView.image = imageGreen;
        cell.selected = true;
        NSLog(@"Selected");
    } else {
        cell.imageView.image = imageRed;
        cell.selected = false;
        NSLog(@"Deselected");
    }
}

Answer 1

我修改了你的代码，检查一下

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"PlacesCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:@"PlacesCell"];
    cell.selectionStyle = UITableViewCellSelectionStyleNone;
}

//Create ImageView
cell.imageView.image = [UIImage imageNamed:@"checkmark.png"];

//Add Gesture Recognizer
UITapGestureRecognizer *tapped = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imageTapped:)];
tapped.numberOfTapsRequired = 1;
[cell.imageView addGestureRecognizer:tapped];
cell.imageView.userInteractionEnabled = YES;
//[cell addSubview:cell.imageView]; 

return cell;

}

//Method controlling what happens when cell's UIImage is tapped
-(void)imageTapped:(UIGestureRecognizer*)gesture
{

UIImageView *selectedImageView=(UIImageView*)[gesture view];

UIImage *imageDefault = [UIImage imageNamed:@"checkmark.png"];
UIImage *imageRed = [UIImage imageNamed:@"checkmark(red).png"];
UIImage *imageGreen = [UIImage imageNamed:@"checkmark(green).png"];

if (selectedImageView.image == imageDefault) {
    selectedImageView.image = imageGreen;
    //cell.selected = true;
    NSLog(@"Selected");
} else {
    selectedImageView.image = imageRed;
    //cell.selected = false;
    NSLog(@"Deselected");
}
}