Question

您好我正在使用tableview.Now我正面临一个问题。在我的tableview中，当我使用Long Gesture时，我需要显示Alert View.it工作正常。当我在警报视图中点击buttonindex 0时，我需要执行一些Task.But，因为我需要indexpath。以下是我执行任务的方法

UILongPressGestureRecognizer *lpgr = [[UILongPressGestureRecognizer alloc]
                                      initWithTarget:self action:@selector(messageDeleteOrForword:)];
lpgr.minimumPressDuration = 2.0; //seconds
lpgr.delegate = self;
[self.tableView addGestureRecognizer:lpgr];

}
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {

if (buttonIndex == 0) {
  [self deleteSpecificMessage];

}
if (buttonIndex==1) {

}
}

 -(void)messageDeleteOrForword:(UILongPressGestureRecognizer *)gestureRecognizer
 {
   UIAlertView *alert=[[UIAlertView alloc] initWithTitle:@"Delete" message:@"Do you want to delete specific message" delegate:self cancelButtonTitle:@"Delete" otherButtonTitles:@"Forword", nil];
[alert show];
}


-(void)deleteSpecificMessage
{

 CGPoint p = [gestureRecognizer locationInView:self.tableView];
  NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:p];
}

但我需要传递一些参数来知道我在下面使用的索引路径 - （无效）deleteSpecificMessage：（ID）发送方 { } 但是如何在alertview中调用和分配参数请帮助我。

Answer 1

显示didselectrowatindexpath的提醒视图。将alertview标记设置为此方法的indexpath。通过这种方式，您将使用indexpath集成警报视图。在alertview委托中，您可以将indexpath作为其标记。因此，您可以使用此标记将其删除或转发为考虑索引路径。

例如：

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

  UIAlertView *alert=[[UIAlertView alloc] initWithTitle:@"Delete" message:@"Do you want to delete specific message" delegate:self cancelButtonTitle:@"Delete" otherButtonTitles:@"Forword", nil];

 alert.tag = indexPath;  //setting tag

 [alert show];
}

更新（在评论中提问）：

你可以这样做，这是一个例子，

UILongPressGestureRecognizer *lpgr = [[UILongPressGestureRecognizer alloc]
                                      initWithTarget:self action:@selector(handleLongPress:)];
lpgr.minimumPressDuration = 2.0; //seconds
lpgr.delegate = self;
[self.myTableView addGestureRecognizer:lpgr];

这里是handleLongpress方法

 -(void)handleLongPress:(UILongPressGestureRecognizer *)gestureRecognizer
{
 CGPoint p = [gestureRecognizer locationInView:self.myTableView];

NSIndexPath *indexPath = [self.myTableView indexPathForRowAtPoint:p];
if (indexPath == nil) {
    NSLog(@"long press on table view but not on a row");
}
else{

    UIAlertView *alert=[[UIAlertView alloc] initWithTitle:@"Delete" message:@"Do you want to delete specific message" delegate:self cancelButtonTitle:@"Delete" otherButtonTitles:@"Forword", nil];

    alert.tag = indexPath;  //setting tag

    [alert show];
}

}

希望这会有所帮助：）

Answer 2

在你的删除方法中你可以添加：

CGPoint location = [gestureRecognizer locationInView:self.tableView];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:location];
UITableViewCell* cell = [self.tableView cellForRowAtIndexPath:indexPath];

Answer 3

您可以使用

获取indexpath

NSIndexPath *selectedIndexPath = [tableView indexPathForSelectedRow];

您可以查看this link

中的更多详情

你也可以在.h文件中加一个IndexPath变量，在选择tableview单元格时可以分配该变量。

首先添加长按手势识别器。

UILongPressGestureRecognizer *longPressGesture = [[UILongPressGestureRecognizer alloc]initWithTarget:self action:@selector(actionLongPressGeature:)];
[longPressGesture setDelegate:self];
[longPressGesture setMinimumPressDuration:0.3];
[tableView addGestureRecognizer:longPressGesture];

即 选项1

-(void)actionLongPressGeature:(UILongPressGestureRecognizer *)gestureRecognizer
{
    CGPoint p = [gestureRecognizer locationInView:tableViewJobs];
   // You need to declare NSIndexPath *indexPathSelected in your .h File
    indexPath = [tableView indexPathForRowAtPoint:p];
    if (indexPath == nil) {
        NSLog(@"long press on table view but not on a row");
    }
    else if (gestureRecognizer.state == UIGestureRecognizerStateBegan)
    {
            // Perform your action i.e AlertView
    }
}

选项2：

-(void)actionLongPressGeature:(UILongPressGestureRecognizer *)gestureRecognizer
{
        // You need to declare NSIndexPath *indexPathSelected in your .h File
    indexPath = [tableView indexPathForSelectedRow];
    if (indexPath == nil) {
        NSLog(@"long press on table view but not on a row");
    }
    else if (gestureRecognizer.state == UIGestureRecognizerStateBegan)
    {
        // Perform your action i.e AlertView
    }
}

以后再使用此变量。

我希望你能找到你想要的东西。

Answer 4

-(void)messageDeleteOrForword:(UILongPressGestureRecognizer *)gestureRecognizer
 {   
     CGPoint p = [gestureRecognizer locationInView:self.myTableView];

     NSIndexPath *indexPath = [self.myTableView indexPathForRowAtPoint:p];
     if (indexPath == nil) {
        NSLog(@"long press on table view but not on a row");
     }
     else{

        NSLog(@"selected row index %ld",(long)indexPath.row);

        UIAlertView *alert=[[UIAlertView alloc] initWithTitle:@"Delete" message:@"Do you want to delete specific message" delegate:self cancelButtonTitle:@"Delete" otherButtonTitles:@"Forword", nil];
        [alert show];
     } 


 }

Answer 5

您还可以将Objective-C关联对象用于运行时属性。 <objc/runtime.h>中提供了此功能。例如：

#import <objc/runtime.h>

-(void)messageDeleteOrForword:(UILongPressGestureRecognizer *)gestureRecognizer
{
   UIAlertView *alert=[[UIAlertView alloc] initWithTitle:@"Delete" message:@"Do you want to delete specific message" delegate:self cancelButtonTitle:@"Delete" otherButtonTitles:@"Forword", nil];
   objc_setAssociatedObject(alert, @"currentIndexPath", indexPath, OBJC_ASSOCIATION_RETAIN);
   [alert show];
}


- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex 
{
   NSIndexPath *idxPath = objc_getAssociatedObject(alertView, @"currentIndexPath");
   NSLog(@"%@",idxPath);

   if (buttonIndex == 0) {
      [self deleteSpecificMessage];
   }

   if (buttonIndex==1) {
   }
}

以下是一些更有帮助的链接。 http://kingscocoa.com/tutorials/associated-objects/ http://nshipster.com/associated-objects/

使用关联对象，您可以使用任何对象附加多个属性并轻松获取。在第一个链接中，您还可以使用定义类别自定义属性。

如何在alertview上找到索引路径？

5 个答案: