objective-c - updateSwitchAtIndexPath 崩溃

Question

我'，在某些单元格中有一个带有 UISwitch 的 UITableView。

我想捕获事件，但是当我尝试添加 indexPath 时它崩溃了。

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{

 //Create cell with all data

    UISwitch *switchview = [[UISwitch alloc] initWithFrame:CGRectZero];
    cell.accessoryView = switchview;
    [switchview addTarget:self action:@selector(updateSwitchAtIndexPath) forControlEvents:UIControlEventTouchUpInside];
}


- (void)updateSwitchAtIndexPath:(NSIndexPath *)indexPath {

   UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
   UISwitch *switchView = (UISwitch *)cell.accessoryView;

   if ([switchView isOn]) {
       NSLog(@"ON");
   } else {
       NSLog(@"OFF");
   }

}

它崩溃了，我想是因为我没有添加 indexPath 参数，但我不知道如何设置它。

 -[ParkingData updateSwitchAtIndexPath]: unrecognized selector sent to instance 0x7b88eb0

谢谢！

Answer 1

[switchview addTarget:self action:@selector(updateSwitchAtIndexPath) forControlEvents:UIControlEventTouchUpInside];

应该

[switchview addTarget:self action:@selector(updateSwitchAtIndexPath:) forControlEvents:UIControlEventTouchUpInside];

你只缺少一个冒号。因为你的方法有参数。

- (void)updateSwitchAtIndexPath:(NSIndexPath *)indexPath

Answer 2

更新

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{

 //Create cell with all data

    UISwitch *switchview = [[UISwitch alloc] initWithFrame:CGRectZero];
    cell.accessoryView = switchview;
    [switchview addTarget:self action:@selector(updateSwitchAtIndexPath:) forControlEvents:UIControlEventTouchUpInside];
}


- (void)updateSwitchAtIndexPath:(UISwitch *)switchview {
   if ([switchView isOn]) {
       NSLog(@"ON");
   } else {
       NSLog(@"OFF");
   }

}

Answer 3

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UISwitch *switchview = [[UISwitch alloc] initWithFrame:CGRectZero];
    cell.accessoryView = switchview;
    [switchview addTarget:self action:@selector(updateSwitchAtIndexPath:) forControlEvents:UIControlEventTouchUpInside];
}

- (void)updateSwitchAtIndexPath:(id)sender
{
   // see the line BELOW
   NSIndexPath *indexPath = [[(UITableView*)[sender superview] superview]indexPathForCell: (UITableViewCell*)[sender superview]];

    if ([sender isOn])
        NSLog(@"ON");
    else
        NSLog(@"OFF");
}

在上面的代码中，发送者表示 UISwitch，如果你想要单元格的 indexPath，那么标记的行对你有帮助。