在UITableViewCells上显示"复制"弹出窗口的简单方法,如地址簿App

Question

有没有一种简单的方法让UITableViewCell的子类在选择保持一段时间之后显示"地址簿"应用程序中的"复制"UIMenuController弹出窗口(参见屏幕截图)？

Answer 1

现在有用于在iOS 5中显示UITableView单元菜单的官方界面.示例(来自表委托):

- (BOOL)tableView:(UITableView *)tableView shouldShowMenuForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return YES;
}

- (BOOL)tableView:(UITableView *)tableView canPerformAction:(SEL)action forRowAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender
{
    return (action == @selector(copy:));
}

- (void)tableView:(UITableView *)tableView performAction:(SEL)action forRowAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender
{
    if (action == @selector(copy:)){
        UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
        [[UIPasteboard generalPasteboard] setString:cell.textLabel.text];
    }
}

我尝试修改UIMenuController的共享控制器来添加我自己的菜单项,我能够添加它并获取它的canPerformAction消息,但返回YES没有帮助; 我无法显示自定义菜单项.从我的实验来看,它看起来只支持复制,剪切和粘贴.[ 编辑自发布以来,我已经学会了如何添加自定义菜单项.]

请注意,仅当实现了所有三个委托方法时,此方法才有效.

Answer 2

iOS 5之前的方法是获取UIMenuController的共享实例,设置目标rect并查看和调用-setMenuVisible:animated:.请记住-canPerformAction:withSender:在您的响应者中实施.

iOS 5之后的方法(以前作为未记录的功能提供)是在数据源中实现这3种方法(请参阅https://developer.apple.com/reference/uikit/uitableviewdelegate#1653389).

-(void)tableView:(UITableView*)tableView performAction:(SEL)action forRowAtIndexPath:(NSIndexPath*)indexPath withSender:(id)sender;
-(BOOL)tableView:(UITableView*)tableView canPerformAction:(SEL)action forRowAtIndexPath:(NSIndexPath*)indexPath withSender:(id)sender;
-(BOOL)tableView:(UITableView*)tableView shouldShowMenuForRowAtIndexPath:(NSIndexPath*)indexPath; 

Answer 3

这是用于复制的Swift语法detailTextLabel.

func tableView(_ tableView: UITableView, shouldShowMenuForRowAt indexPath: IndexPath) -> Bool {
    return (tableView.cellForRow(at: indexPath)?.detailTextLabel?.text) != nil
}

func tableView(_ tableView: UITableView, canPerformAction action: Selector, forRowAt indexPath: IndexPath, withSender sender: Any?) -> Bool {
    return action == #selector(copy(_:))
}

func tableView(_ tableView: UITableView, performAction action: Selector, forRowAt indexPath: IndexPath, withSender sender: Any?) {
    if action == #selector(copy(_:)) {
        let cell = tableView.cellForRow(at: indexPath)
        let pasteboard = UIPasteboard.general
        pasteboard.string = cell?.detailTextLabel?.text
    }
}

Answer 4

您的UITableViewCell子类可能如下所示

@interface MenuTableViewCell : UITableViewCell {
}
- (IBAction)copy:(id)sender;
- (void)showMenu;

@end


@implementation MenuTableViewCell

- (BOOL)canBecomeFirstResponder {
    return YES;
}
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
    if (action == @selector(copy:)) {
        return YES;
    }
    return NO;
}
- (IBAction)copy:(id)sender {
}
- (void)showMenu {
    [[UIMenuController sharedMenuController] setMenuVisible:NO animated:YES];
    [self becomeFirstResponder];
    [[UIMenuController sharedMenuController] update];
    [[UIMenuController sharedMenuController] setTargetRect:CGRectZero inView:self];
    [[UIMenuController sharedMenuController] setMenuVisible:YES animated:YES];

}

@end

而UITableView委托方法就像

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

    static NSString *CellIdentifier = @"Cell";

    MenuTableViewCell *cell = (MenuTableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[MenuTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }

    // Configure the cell.
    return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    MenuTableViewCell *cell = (MenuTableViewCell *)[tableView cellForRowAtIndexPath:indexPath];
    [cell showMenu];
}

Answer 5

 #pragma mark - COPY/PASTE Cell Text via Menu

- (BOOL)tableView:(UITableView *)tableView shouldShowMenuForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return YES;
}

- (BOOL)tableView:(UITableView *)tableView canPerformAction:(SEL)action forRowAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender
{
    return (action == @selector(copy:));
}

- (void)tableView:(UITableView *)tableView performAction:(SEL)action forRowAtIndexPath:(NSIndexPath *)indexPath withSender:(id)sender
{
    if (action == @selector(copy:))
    {
        UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
        UIPasteboard *pasteBoard = [UIPasteboard generalPasteboard];
        [pasteBoard setString:cell.textLabel.text];
    }
}