如何在iPad中快速显示“iPad”

Question

我需要上传图片和pdf文件，所以我使用的是HSAttachmentPicker框架，我可以打开选择器选项，可以在iPhone中上传图像和pdf，但是当我单击“上传”按钮时，它会在iPad中崩溃。

错误：

您必须通过警报控制器的popoverPresentationController提供此弹出器的位置信息。您必须提供sourceView和sourceRect或barButtonItem。如果在呈现警报控制器时不知道此信息，则可以在UIPopoverPresentationControllerDelegate方法-prepareForPopoverPresentation中提供该信息。

但是HSAttachmentPicker是一个框架，所以我应该在哪里为iPad添加代码

代码：，这是我在上传图像类中编写的代码

    let picker = HSAttachmentPicker()

    @IBAction func uploadButtonTapped(_ sender: UIButton) {
    picker.delegate = self
    picker.showAttachmentMenu()
    }

extension PostEnquiryViewController: HSAttachmentPickerDelegate {
func attachmentPickerMenu(_ menu: HSAttachmentPicker, showErrorMessage errorMessage: String) {
}

func attachmentPickerMenuDismissed(_ menu: HSAttachmentPicker) {
}

func attachmentPickerMenu(_ menu: HSAttachmentPicker, show controller: UIViewController, completion: (() -> Void)? = nil) {
    self.present(controller, animated: true, completion: completion)
}

func attachmentPickerMenu(_ menu: HSAttachmentPicker, upload data: Data, filename: String, image: UIImage?) {

    if !data.isEmpty && (filename as NSString).pathExtension == "pdf" {
        self.attachmentFiles.append(.init(data: data, fileName: filename))
        self.attachmentImages.append(.init(image: UIImage(named: "pdf")!, imageName: filename))
        self.uploadFileImage.image = UIImage(named: "pdf")
    }
    if let img = image {
        DispatchQueue.main.async {
            self.uploadFileImage.image = img
        }
        self.attachmentImages.append(.init(image: img, imageName: filename))
    }
}
}

这里是showAttachmentMenu框架文件中的代码：在这里添加iPad的代码。请指点。

  - (void)showAttachmentMenu {
self.selfReference = self;
UIAlertController *picker = [UIAlertController alertControllerWithTitle:nil message:nil preferredStyle:UIAlertControllerStyleActionSheet];
NSString *showPhotosPermissionSettingsMessage = [NSBundle.mainBundle objectForInfoDictionaryKey:@"NSPhotoLibraryUsageDescription"];
if ([UIImagePickerController isSourceTypeAvailable: UIImagePickerControllerSourceTypeCamera] && showPhotosPermissionSettingsMessage != nil) {
    UIAlertAction *takePhotoAction = [UIAlertAction actionWithTitle:[self translateString:@"Take Photo"] style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        if (@available(iOS 14.0, *)) {
            [self validatePhotosPermissionsWithAccessLevel:PHAccessLevelAddOnly completion:^{
                [self showImagePicker:UIImagePickerControllerSourceTypeCamera];
            }];
        } else {
            [self validatePhotosPermissions:^{
                [self showImagePicker:UIImagePickerControllerSourceTypeCamera];
            }];
        }
    }];
    [picker addAction:takePhotoAction];
}

if (showPhotosPermissionSettingsMessage != nil) {
    if (@available(iOS 14.0, *)) {
        // the app already has access to the Photo Library so we're safe to add `Use Last Photo` here
        if ([PHPhotoLibrary authorizationStatusForAccessLevel:PHAccessLevelReadWrite] == PHAuthorizationStatusAuthorized) {
            UIAlertAction *useLastPhotoAction = [UIAlertAction actionWithTitle:[self translateString:@"Use Last Photo"] style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
                [self useLastPhoto];
            }];
            [picker addAction:useLastPhotoAction];
        }
    } else {
        UIAlertAction *useLastPhotoAction = [UIAlertAction actionWithTitle:[self translateString:@"Use Last Photo"] style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
            [self validatePhotosPermissions:^{
                [self useLastPhoto];
            }];
        }];
        [picker addAction:useLastPhotoAction];
    }
}

if (showPhotosPermissionSettingsMessage != nil) {
    UIAlertAction *chooseFromLibraryAction = [UIAlertAction actionWithTitle:[self translateString:@"Choose from Library"] style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        if (@available(iOS 14, *)) {
            // don't request access to users photo library since we don't need it with PHPicker
            [self showPhotoPicker];
        } else {
            [self validatePhotosPermissions:^{
                [self showImagePicker:UIImagePickerControllerSourceTypePhotoLibrary];
            }];
        }
    }];
    [picker addAction:chooseFromLibraryAction];
}

UIAlertAction *importFileFromAction = [UIAlertAction actionWithTitle:[self translateString:@"Import File from"] style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
    [self showDocumentPicker];
}];
[picker addAction:importFileFromAction];

UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:[self translateString:@"Cancel"] style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
    [self dismissed];
}];

[picker addAction:cancelAction];

[self.delegate attachmentPickerMenu:self showController:picker completion:nil];
}

Answer 1

阅读popover演示文稿：文档是个好主意。

如果您查看HSAttachmentPicker提供的示例中的视图控制器，您将看到示例应用程序是如何处理它的。是的，在目标-C.但在Swift中，它几乎是一样的：

func attachmentPickerMenu(_ menu: HSAttachmentPicker, show controller: UIViewController, completion: (() -> Void)? = nil) {

    // popover will be non-nil if we're on an iPad
    if let popover = controller.popoverPresentationController {
        
        // we want the popover arrow pointing to the button
        popover.sourceView = self.uploadButton
        
    }

    self.present(controller, animated: true, completion: completion)
}

下面是一个完整的、可运行的示例：

import UIKit

class ViewController: UIViewController {

    let uploadButton = UIButton()

    override func viewDidLoad() {
        super.viewDidLoad()
        
        view.backgroundColor = .systemYellow
        
        uploadButton.setTitle("Tap to Upload", for: [])
        uploadButton.setTitleColor(.white, for: .normal)
        uploadButton.setTitleColor(.lightGray, for: .highlighted)
        uploadButton.backgroundColor = .systemBlue
        uploadButton.layer.cornerRadius = 8.0
        
        uploadButton.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(uploadButton)
        
        let g = view.safeAreaLayoutGuide
        NSLayoutConstraint.activate([
            // let's put the button near the bottom of the screen
            uploadButton.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: -40.0),
            uploadButton.widthAnchor.constraint(equalToConstant: 200.0),
            uploadButton.heightAnchor.constraint(equalToConstant: 60.0),
            uploadButton.centerXAnchor.constraint(equalTo: g.centerXAnchor),
        ])
        
        uploadButton.addTarget(self, action: #selector(uploadButtonTapped(_:)), for: .touchUpInside)
    }

    @IBAction func uploadButtonTapped(_ sender: UIButton) {
        let picker = HSAttachmentPicker()
        picker.delegate = self
        picker.showAttachmentMenu()
    }
}

extension ViewController: HSAttachmentPickerDelegate {
    func attachmentPickerMenu(_ menu: HSAttachmentPicker, showErrorMessage errorMessage: String) {
        // Handle errors
    }
    
    func attachmentPickerMenuDismissed(_ menu: HSAttachmentPicker) {
        // Run some code when the picker is dismissed
    }
    
    func attachmentPickerMenu(_ menu: HSAttachmentPicker, show controller: UIViewController, completion: (() -> Void)? = nil) {

        // popover will be non-nil if we're on an iPad
        if let popover = controller.popoverPresentationController {
            
            // we want the popover arrow pointing to the button
            popover.sourceView = self.uploadButton
            
        }

        self.present(controller, animated: true, completion: completion)
    }
    
    func attachmentPickerMenu(_ menu: HSAttachmentPicker, upload data: Data, filename: String, image: UIImage?) {
        // Do something with the data of the selected attachment, i.e. upload it to a web service
    }
}