[英]create a UILabel when view appears and destroy it when view disappears
[英]UILabel appears and disappears from the bottom bar of UIViewControllers
我想將UILabel添加到導航控制器推送和彈出的所有UIViewControllers的底部工具欄中:
- (void)init
{
//Bottom toolbar label
self.titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0.0 , 11.0f, 320, 21.0f)];
[self.titleLabel setFont:[UIFont fontWithName:@"Helvetica-Bold" size:14]];
[self.titleLabel setBackgroundColor:[UIColor clearColor]];
[self.titleLabel setTextColor:[UIColor whiteColor]];
[self.titleLabel setText:@"Selected Comics: 0"];
[self.titleLabel setTextAlignment:UITextAlignmentLeft];
}
- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
UIBarButtonItem *labelButton = [[UIBarButtonItem alloc] initWithCustomView:self.titleLabel];
UIBarButtonItem *flex = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:self action:nil] autorelease];
[viewController setToolbarItems:[NSArray arrayWithObjects:labelButton, flex, sortButton, nil] animated:animated];
[labelButton release];
}
但是,當我按下並彈出一個視圖控制器后,標簽出現並立即消失。 另一個按鈕(sortButton)仍然可見。
如何使標簽可見?
謝謝
您的問題是:self.titleLabel。
多個labelButton實例都引用該視圖,並且當您設置工具欄項目時(我假設動畫== YES),titleLabel將從您不希望看到的其超級視圖中刪除。
為每種用法創建一個新的titleLabel,您的問題將消失。
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