[ios] UIBarButtonItem을 표시하거나 숨기려면 어떻게합니까?

버튼을 강력한 콘센트 에 저장하고 (호출하자 myButton) 추가하거나 제거하려면 다음을 수행하십시오.

// Get the reference to the current toolbar buttons
NSMutableArray *toolbarButtons = [self.toolbarItems mutableCopy];

// This is how you remove the button from the toolbar and animate it
[toolbarButtons removeObject:self.myButton];
[self setToolbarItems:toolbarButtons animated:YES];

// This is how you add the button to the toolbar and animate it
if (![toolbarButtons containsObject:self.myButton]) {
    // The following line adds the object to the end of the array.  
    // If you want to add the button somewhere else, use the `insertObject:atIndex:` 
    // method instead of the `addObject` method.
    [toolbarButtons addObject:self.myButton];
    [self setToolbarItems:toolbarButtons animated:YES];
}

콘센트에 저장되어 있기 때문에 도구 모음에없는 경우에도 참조를 유지합니다.

답변

[self.deleteButton setEnabled:NO]; 
[self.deleteButton setTintColor: [UIColor clearColor]];

[self.deleteButton setEnabled:YES];
[self.deleteButton setTintColor:nil];

hide:  barbuttonItem.width = 0.01;
show:  barbuttonItem.width = 0; //(0 defaults to normal button width, which is the width of the text)

-(void)toggleBarButton:(bool)show
{
    if (show) {
        btn.style = UIBarButtonItemStyleBordered;
        btn.enabled = true;
        btn.title = @"MyTitle";
    } else {
        btn.style = UIBarButtonItemStylePlain;
        btn.enabled = false;
        btn.title = nil;
    }
}

navBar.topItem.rightBarButtonItem = nil;

self.deleteButton.isEnabled = false
self.deleteButton.tintColor = UIColor.clear

self.deleteButton.isEnabled = true
self.deleteButton.tintColor = UIColor.blue