QLPreviewController NavigationBar barTintColor答案

【问题标题】：QLPreviewController NavigationBar barTintColorQLPreviewController NavigationBar barTintColor
【发布时间】：2017-12-06 11:49:13
【问题描述】：

当我self.present()QLPreviewController时，它的NavigationBar失去颜色，这是在AppDelegate中实现的。

    UINavigationBar.appearance().isTranslucent = false
    UINavigationBar.appearance().tintColor = UIColor.white
    UINavigationBar.appearance().barTintColor = Colors.fifth   // Blue color
    UINavigationBar.appearance().titleTextAttributes = [NSAttributedStringKey.foregroundColor: UIColor.white]
    UINavigationBar.appearance().shadowImage = UIImage()

QLPreviewController 实现：

let preview = QLPreviewController()
preview.dataSource = self

func numberOfPreviewItems(in controller: QLPreviewController) -> Int {
    return 1
}

func previewController(_ controller: QLPreviewController, previewItemAt index: Int) -> QLPreviewItem {
    return fileURL! as QLPreviewItem
}

fileprivate func showDocument(fileId: Int) {
    SVProgressHUD.show()
    self.fileService.download(id: fileId) {
        url, error in

        if error == nil {
            self.fileURL = url
            if QLPreviewController.canPreview(self.fileURL! as QLPreviewItem) {
                self.present(self.preview, animated: true, completion: nil)
                SVProgressHUD.dismiss()
            } else {
                SVProgressHUD.showDismissableError(with: "Произошла ошибка во время чтения файла \(url!.lastPathComponent)")
            }
        } else {
            SVProgressHUD.showDismissableError(with: error?.localizedDescription)
        }
    }
}

我尝试self.show() 并且它的NavigationBar 是好的！我想将QLPreviewController's NavigationBar 颜色设置为与AppDelegate's UINavigationBar 相同的设置。如何以编程方式更改它？提前致谢！

【问题讨论】：

标签： ios uiviewcontroller uinavigationcontroller swift4 qlpreviewcontroller

【解决方案1】：

首先将 UINavigationController 和您的 QLPreviewController 实例化为它的 根视图控制器。然后您可以显示该导航栏，该导航栏将具有您在应用委托类中设置的属性。

    let preview = QLPreviewController()
    preview.dataSource = self
    preview.currentPreviewItemIndex = 0
    let navBar = UINavigationController(rootViewController: preview)
    let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(self.dismissQLPreviewController))
    preview.navigationItem.leftBarButtonItem = doneButton
    self.present(navBar, animated: true)

【讨论】：