我正在尝试使以下代码工作：
UIMenuController * menu = [UIMenuController sharedMenuController];
[menu setTargetRect: CGRectMake(100, 100, 100, 100) inView: self.view];
[menu setMenuVisible: YES animated: YES];
菜单实例已准备好但未显示 - 宽度始终为零。
或者有没有关于这个UIPasteboard/UIMenuController主题的示例代码？
【问题讨论】：
标签： iphone cocoa-touch iphone-sdk-3.0 uimenucontroller
即使阅读了您的所有答案，我也无法使其正常工作。我正在展示适用于所有人的现成代码。
假设我们有一个名为 Controller 的控制器类。您可以简单地将以下代码粘贴到此控制器，以使菜单在其视图上工作：
- (void)loadView {
[super loadView];
UILongPressGestureRecognizer *gr = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress:)];
[self.view addGestureRecognizer:gr];
}
- (void) longPress:(UILongPressGestureRecognizer *) gestureRecognizer {
if ([gestureRecognizer state] == UIGestureRecognizerStateBegan) {
CGPoint location = [gestureRecognizer locationInView:[gestureRecognizer view]];
UIMenuController *menuController = [UIMenuController sharedMenuController];
UIMenuItem *resetMenuItem = [[UIMenuItem alloc] initWithTitle:@"Item" action:@selector(menuItemClicked:)];
NSAssert([self becomeFirstResponder], @"Sorry, UIMenuController will not work with %@ since it cannot become first responder", self);
[menuController setMenuItems:[NSArray arrayWithObject:resetMenuItem]];
[menuController setTargetRect:CGRectMake(location.x, location.y, 0.0f, 0.0f) inView:[gestureRecognizer view]];
[menuController setMenuVisible:YES animated:YES];
}
}
- (void) copy:(id) sender {
// called when copy clicked in menu
}
- (void) menuItemClicked:(id) sender {
// called when Item clicked in menu
}
- (BOOL) canPerformAction:(SEL)selector withSender:(id) sender {
if (selector == @selector(menuItemClicked:) || selector == @selector(copy:)) {
return YES;
}
return NO;
}
- (BOOL) canBecomeFirstResponder {
return YES;
}
为了使菜单工作必须做的是 firstResponder（在我们的例子中是我们的控制器 - 参见 [self becomeFirstResponder] 行）必须能够成为第一响应者（覆盖方法 canBecomeFirstResponder 导致默认实现返回 NO ) 以及- (BOOL) canPerformAction:(SEL)selector withSender:(id) sender 应该对firstResponder 可以执行的任何操作返回YES
【讨论】：
如果您正在实现自定义视图并且该视图应该是响应者（与其他视图相反，例如 UITextField），您需要在视图中覆盖 canBecomeFirstResponder 函数并返回 YES：
- (BOOL)canBecomeFirstResponder {
return YES;
}
然后，当您显示菜单时，您应该执行以下操作：
- (void)myMenuFunc {
if (![self becomeFirstResponder]) {
NSLog(@"couldn't become first responder");
return;
}
UIMenuController *theMenu = [UIMenuController sharedMenuController];
CGRect selectionRect = CGRectMake(0, 0, 0, 0);
[theMenu setTargetRect:selectionRect inView:self];
[theMenu setMenuVisible:YES animated:YES];
}
【讨论】：
万一有人仍然有问题：我的菜单曾经可以工作，但有一天却奇迹般地停止工作。我的应用程序中的其他所有内容仍然有效。现在我已经从application:didFinishLaunchingWithOptions: 方法中删除了[window makeKeyAndVisible] 方法，虽然其他一切仍然有效，但这会破坏UIMenuController！
我这边的愚蠢错误，很难找到罪魁祸首......
【讨论】：
要显示 UIMenuController 必须添加以下内容
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
if (action == @selector(cut:))
return NO;
else if (action == @selector(copy:))
return YES;
else if (action == @selector(paste:))
return NO;
else if (action == @selector(select:) || action == @selector(selectAll:))
return NO;
else
return [super canPerformAction:action withSender:sender];
}
【讨论】：
我认为 Cam 是对的，需要同时覆盖 canPerformAction 和 canBecomeFirstResponder
- (BOOL) canPerformAction:(SEL)action withSender:(id)sender
{
if (action == @selector(doSomething:)) {
return YES;
}
return NO;
}
- (BOOL)canBecomeFirstResponder {
return YES;
}
【讨论】：
// MyView.h
@interface MyView : UIView {
IBOutlet UITextField * textField_;
}
@end
// MyView.m
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
NSLog(@"show menu");
[textField_ becomeFirstResponder];
// [self.window becomeFirstResponder];
UIMenuController * menu = [UIMenuController sharedMenuController];
[menu setTargetRect: CGRectMake(0, 0, 100, 10) inView: self];
[menu setMenuVisible: YES animated: YES];
NSLog(@"menu width %f, visible %d", menu.menuFrame.size.width, menu.menuVisible);
}
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender{
return YES;
}
您需要在 canPerformAction:withSender: 中添加更多代码 - 它应该检查粘贴板和您的选择状态。 Apple 的 iPhone 应用程序编程指南提供了几个代码 sn-ps。
【讨论】：
您不必将UIMenuController* menu 添加到主视图或子视图，例如self.view?
我认为这类似于[self.view addSubView:menu.view]; 或者我错过了你的问题的重点。您可能还想设置菜单视图的框架。
【讨论】：
UIMenuController 没有视图。我刚刚从苹果的iPhone Application Programming Guide: Event Handling 中搜索了一些代码：
清单 3-4 显示编辑菜单
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *theTouch = [touches anyObject]; if ([theTouch tapCount] == 2 && [self becomeFirstResponder]) { // selection management code goes here... // bring up editing menu. UIMenuController *theMenu = [UIMenuController sharedMenuController]; CGRect selectionRect = CGRectMake(currentSelection.x, currentSelection.y, SIDE, SIDE); [theMenu setTargetRect:selectionRect inView:self]; [theMenu setMenuVisible:YES animated:YES]; } }
【讨论】：
我是通过以下方式完成的。只需在很短的初始化延迟后调用显示菜单的方法。我不想从视图控制器调用它，也没有找到表明我的自定义视图出现并且我准备好显示菜单的事件。所以从我的角度来看，这样就可以了。延迟可以减少，但这取决于您。
@implementation DTSignatureImageView
- (id)initWithImage:(UIImage *)image
{
self = [super initWithImage:image];
if(self){
self.contentMode = UIViewContentModeScaleAspectFit;
self.frame = CGRectMake(0, 0, image.size.width / 2.5, image.size.height / 2.5);
self.userInteractionEnabled = YES;
UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(signatureDidPan:)];
[self addGestureRecognizer:pan];
[self becomeFirstResponder];
[self performSelector:@selector(showMenu) withObject:nil afterDelay:0.5];
}
return self;
}
- (BOOL)canBecomeFirstResponder
{
return YES;
}
- (void)showMenu
{
UIMenuController *menu = [UIMenuController sharedMenuController];
menu.menuItems = @[
[[UIMenuItem alloc] initWithTitle:@"Apply" action:@selector(applySignature)],
[[UIMenuItem alloc] initWithTitle:@"Update" action:@selector(updateSignature)],
[[UIMenuItem alloc] initWithTitle:@"Clear" action:@selector(delegateSignature)]];
[menu setTargetRect:self.bounds inView:self];
[menu setMenuVisible:YES animated:YES];
}
- (NSArray *)menuActions
{
static NSArray *actions = nil;
if (actions == nil){
actions = @[
NSStringFromSelector(@selector(applySignature)),
NSStringFromSelector(@selector(updateSignature)),
NSStringFromSelector(@selector(delegateSignature))];
}
return actions;
}
- (void) signatureDidPan: (UIPanGestureRecognizer *)gesture
{
switch (gesture.state) {
case UIGestureRecognizerStateBegan: {
[[UIMenuController sharedMenuController] setMenuVisible:NO animated:YES];
break;
}
case UIGestureRecognizerStateEnded: {
[self becomeFirstResponder];
[self showMenu];
}
default:
break;
}
CGPoint point = [gesture locationInView:gesture.view.superview];
gesture.view.center = point;
}
【讨论】：