如何检测UITableView 中某个单元格的双击？
即如果用户进行了一次触摸，我想执行一个操作，如果用户进行了两次触摸，我想执行另一个操作？我还需要知道进行触摸的索引路径。
我怎样才能实现这个目标？
谢谢。
【问题讨论】：
标签： iphone cocoa-touch uitableview
如果您不想创建UITableView 的子类，请使用带有表视图didSelectRowAtIndex: 的计时器
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
//checking for double taps here
if(tapCount == 1 && tapTimer != nil && tappedRow == indexPath.row){
//double tap - Put your double tap code here
[tapTimer invalidate];
[self setTapTimer:nil];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Double Tap" message:@"You double-tapped the row" delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
[alert show];
[alert release];
}
else if(tapCount == 0){
//This is the first tap. If there is no tap till tapTimer is fired, it is a single tap
tapCount = tapCount + 1;
tappedRow = indexPath.row;
[self setTapTimer:[NSTimer scheduledTimerWithTimeInterval:0.2 target:self selector:@selector(tapTimerFired:) userInfo:nil repeats:NO]];
}
else if(tappedRow != indexPath.row){
//tap on new row
tapCount = 0;
if(tapTimer != nil){
[tapTimer invalidate];
[self setTapTimer:nil];
}
}
}
- (void)tapTimerFired:(NSTimer *)aTimer{
//timer fired, there was a single tap on indexPath.row = tappedRow
if(tapTimer != nil){
tapCount = 0;
tappedRow = -1;
}
}
HTH
【讨论】：
在您的UITableView 类中重写此方法
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
if(((UITouch *)[touches anyObject]).tapCount == 2)
{
NSLog(@"DOUBLE TOUCH");
}
[super touchesEnded:touches withEvent:event];
}
【讨论】：
UITableViewCell类中。
在您的 UITableView 子类中，执行以下操作：
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
for (UITouch* touch in touches) {
if (touch.tapCount == 2)
{
CGPoint where = [touch locationInView:self];
NSIndexPath* ip = [self indexPathForRowAtPoint:where];
NSLog(@"double clicked index path: %@", ip);
// do something useful with index path 'ip'
}
}
[super touchesEnded:touches withEvent:event];
}
【讨论】：
先定义：
int tapCount;
NSIndexPath *tableSelection;
作为 .h 文件中的类级别变量并进行所有必要的设置。那么……
- (void)tableView(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
tableSelection = indexPath;
tapCount++;
switch (tapCount) {
case 1: //single tap
[self performSelector:@selector(singleTap) withObject: nil afterDelay: .4];
break;
case 2: //double tap
[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(singleTap) object:nil];
[self performSelector:@selector(doubleTap) withObject: nil];
break;
default:
break;
}
}
#pragma mark -
#pragma mark Table Tap/multiTap
- (void)singleTap {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Single tap detected" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
tapCount = 0;
}
- (void)doubleTap {
NSUInteger row = [tableSelection row];
companyName = [self.suppliers objectAtIndex:row];
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"DoubleTap" delegate:nil cancelButtonTitle:@"Yes" otherButtonTitles: nil];
[alert show];
tapCount = 0;
}
【讨论】：
[self doubleTap];代替[self performSelector:@selector(doubleTap) withObject: nil]; ;)
if([touch tapCount] == 1)
{
[self performSelector:@selector(singleTapRecevied) withObject:self afterDelay:0.3];
} else if ([touch tapCount] == 2)
{
[TapEnableImageView cancelPreviousPerformRequestsWithTarget:self selector:@selector(singleTapRecevied) object:self];
}
使用 performSelector 调用选择器而不是使用计时器。这解决了@V1ru8 提到的问题。
【讨论】：
我选择通过覆盖UITableViewCell 来实现它。
MyTableViewCell.h
@interface MyTableViewCell : UITableViewCell
@property (nonatomic, assign) int numberOfClicks;
@end
MyTableViewCell.m
@implementation MyTableViewCell
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *aTouch = [touches anyObject];
self.numberOfClicks = [aTouch tapCount];
[super touchesEnded:touches withEvent:event];
}
TableViewController.m
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
MyTableViewCell *myCell = (MyTableViewCell*) [self.tableView cellForRowAtIndexPath:indexPath];
NSLog(@"clicks:%d", myCell.numberOfClicks);
if (myCell.numberOfClicks == 2) {
NSLog(@"Double clicked");
}
}
【讨论】：
比较答案中的 Swift 3 解决方案。无需任何扩展，只需添加此代码即可。
override func viewDidLoad() {
viewDidLoad()
let doubleTapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(handleDoubleTap(sender:)))
doubleTapGestureRecognizer.numberOfTapsRequired = 2
tableView.addGestureRecognizer(doubleTapGestureRecognizer)
let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(handleTapGesture(sender:)))
tapGestureRecognizer.numberOfTapsRequired = 1
tapGestureRecognizer.require(toFail: doubleTapGestureRecognizer)
tableView.addGestureRecognizer(tapGestureRecognizer)
}
func handleTapGesture(sender: UITapGestureRecognizer) {
let touchPoint = sender.location(in: tableView)
if let indexPath = tableView.indexPathForRow(at: touchPoint) {
print(indexPath)
}
}
func handleDoubleTap(sender: UITapGestureRecognizer) {
let touchPoint = sender.location(in: tableView)
if let indexPath = tableView.indexPathForRow(at: touchPoint) {
print(indexPath)
}
}
【讨论】：
require(toFail:) 让它工作developer.apple.com/documentation/uikit/uigesturerecognizer/…
另一个答案
int touches;
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
touches++;
if(touches==2){
//your action
}
}
- (void)tableView:(UITableView *)tableView didDeselectRowAtIndexPath:(NSIndexPath *)indexPath
{
touches=0;
}
【讨论】：
您可能需要继承 UITableView 并覆盖任何适当的触摸事件（touchesBegan:withEvent;、touchesEnded:withEvent 等）检查事件以查看有多少触摸，并执行您的自定义行为。不要忘记调用UITableView's touch 方法，否则您将无法获得默认行为。
【讨论】：
根据@lostInTransit，我在 Swift 中准备了代码
var tapCount:Int = 0
var tapTimer:NSTimer?
var tappedRow:Int?
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
//checking for double taps here
if(tapCount == 1 && tapTimer != nil && tappedRow == indexPath.row){
//double tap - Put your double tap code here
tapTimer?.invalidate()
tapTimer = nil
}
else if(tapCount == 0){
//This is the first tap. If there is no tap till tapTimer is fired, it is a single tap
tapCount = tapCount + 1;
tappedRow = indexPath.row;
tapTimer = NSTimer.scheduledTimerWithTimeInterval(0.2, target: self, selector: "tapTimerFired:", userInfo: nil, repeats: false)
}
else if(tappedRow != indexPath.row){
//tap on new row
tapCount = 0;
if(tapTimer != nil){
tapTimer?.invalidate()
tapTimer = nil
}
}
}
func tapTimerFired(aTimer:NSTimer){
//timer fired, there was a single tap on indexPath.row = tappedRow
if(tapTimer != nil){
tapCount = 0;
tappedRow = -1;
}
}
【讨论】：
注意：请参阅下面的 cmets 以了解虽然此解决方案对我有用，但它仍然可能不是一个好主意。
创建UITableView 或UITableViewCell 的子类（以及使用计时器）的替代方法是使用类别扩展UITableViewCell 类，例如（使用@oxigen 的答案，在这种情况下为单元格而不是表格）：
@implementation UITableViewCell (DoubleTap)
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
if(((UITouch *)[touches anyObject]).tapCount == 2)
{
NSLog(@"DOUBLE TOUCH");
}
[super touchesEnded:touches withEvent:event];
}
@end
这样您就不必用新的类名重命名UITableViewCell 的现有实例（将扩展该类的所有实例）。
请注意，现在super 在这种情况下（这是一个类别）不是指UITableView，而是指它的超级UITView。但是对touchesEnded:withEvent: 的实际方法调用在UIResponder 中（其中UITView 和UITableViewCell 都是子类），所以没有区别。
【讨论】：
UITableViewCell 不是一个类别，所以我看不出这里会有什么影响。但是我已经更新了答案的最后一部分以使其更加清晰。
这是我的完整解决方案：
CustomTableView.h
//
// CustomTableView.h
//
#import <UIKit/UIKit.h>
@interface CustomTableView : UITableView
// Nothing needed here
@end
CustomTableView.m
//
// CustomTableView.m
//
#import "CustomTableView.h"
@implementation CustomTableView
//
// Touch event ended
//
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
// For each event received
for (UITouch * touch in touches) {
NSIndexPath * indexPath = [self indexPathForRowAtPoint: [touch locationInView:self] ];
// One tap happened
if([touch tapCount] == 1)
{
// Call the single tap method after a delay
[self performSelector: @selector(singleTapReceived:)
withObject: indexPath
afterDelay: 0.3];
}
// Two taps happened
else if ([touch tapCount] == 2)
{
// Cancel the delayed call to the single tap method
[NSObject cancelPreviousPerformRequestsWithTarget: self
selector: @selector(singleTapReceived:)
object: indexPath ];
// Call the double tap method instead
[self performSelector: @selector(doubleTapReceived:)
withObject: indexPath ];
}
}
// Pass the event to super
[super touchesEnded: touches
withEvent: event];
}
//
// Single Tap
//
-(void) singleTapReceived:(NSIndexPath *) indexPath
{
NSLog(@"singleTapReceived - row: %ld",(long)indexPath.row);
}
//
// Double Tap
//
-(void) doubleTapReceived:(NSIndexPath *) indexPath
{
NSLog(@"doubleTapReceived - row: %ld",(long)indexPath.row);
}
@end
【讨论】：
oxigen 答案的改进。
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
if(touch.tapCount == 2) {
CGPoint touchPoint = [touch locationInView:self];
NSIndexPath *touchIndex = [self indexPathForRowAtPoint:touchPoint];
if (touchIndex) {
// Call some callback function and pass 'touchIndex'.
}
}
[super touchesEnded:touches withEvent:event];
}
【讨论】：
此解决方案仅适用于 UICollectionView 或 UITableView 的单元格。
首先声明这些变量
int number_of_clicks;
BOOL thread_started;
然后将此代码放入您的 didSelectItemAtIndexPath 中
++number_of_clicks;
if (!thread_started) {
thread_started = YES;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW,
0.25 * NSEC_PER_SEC),
dispatch_get_main_queue(),^{
if (number_of_clicks == 1) {
ATLog(@"ONE");
}else if(number_of_clicks == 2){
ATLog(@"DOUBLE");
}
number_of_clicks = 0;
thread_started = NO;
});
}
0.25 是两次点击之间的延迟。我认为 0.25 非常适合检测这种类型的点击。现在您只能分别检测一次单击和两次单击。祝你好运
【讨论】：