UIPicker检测当前所选行的点击/触摸 [英] UIPicker detect tap / touch on currently selected row

问题描述

好的，我有一个 UIPickerView ，当用户点击当前选定的行时，我想做点什么。我现在正在使用它，如果他们点击未选中的行，它会旋转到所选的中心视图。

Okay guys, I have a UIPickerView and I want to do something when the user TAPS the currently selected row. I have it working right now where if they tap a row which is NOT selected, it rotates to the selected center view.

然而，当他们点击这个已选择的行时，未调用方法 didSelectRow 。我需要在点击行时执行的操作，而不是在选中时执行的操作。有什么想法？

However, when they tap this already selected row, the method didSelectRow is not called. I need something that executes when they tap the row, not when it becomes selected. Any ideas?

推荐答案

首先，将类符合 UIGestureRecognizerDelegate 协议

然后，在视图设置中：

UITapGestureRecognizer *tapToSelect = [[UITapGestureRecognizer alloc]initWithTarget:self
                                                                                 action:@selector(tappedToSelectRow:)];
tapToSelect.delegate = self;
[self.pickerView addGestureRecognizer:tapToSelect];

以及其他地方：

#pragma mark - Actions

- (IBAction)tappedToSelectRow:(UITapGestureRecognizer *)tapRecognizer
{
    if (tapRecognizer.state == UIGestureRecognizerStateEnded) {
        CGFloat rowHeight = [self.pickerView rowSizeForComponent:0].height;
        CGRect selectedRowFrame = CGRectInset(self.pickerView.bounds, 0.0, (CGRectGetHeight(self.pickerView.frame) - rowHeight) / 2.0 );
        BOOL userTappedOnSelectedRow = (CGRectContainsPoint(selectedRowFrame, [tapRecognizer locationInView:self.pickerView]));
        if (userTappedOnSelectedRow) {
            NSInteger selectedRow = [self.pickerView selectedRowInComponent:0];
            [self pickerView:self.pickerView didSelectRow:selectedRow inComponent:0];
        }
    }
}

#pragma mark - UIGestureRecognizerDelegate

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    return true;
}

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