[英]How do I load this image data from disk and present it in my SwiftUI List?
I have used an imagePicker
in SwiftUI
to select an image from the user's photo album, and save this image to disk under a unique id.我在
SwiftUI
使用了一个imagePicker
从用户的相册中选择了一个图像,并将这个图像以唯一的 id 保存到磁盘。 Here is saving the image (as Data):这是保存图像(作为数据):
func saveImage(imageName: String, image: Data) {
guard let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else { return }
let fileName = imageName
let fileURL = documentsDirectory.appendingPathComponent(fileName)
//Checks if file exists, removes it if so.
if FileManager.default.fileExists(atPath: fileURL.path) {
do {
try FileManager.default.removeItem(atPath: fileURL.path)
print("Removed old image")
} catch let removeError {
print("couldn't remove file at path", removeError)
}
}
do {
try image.write(to: fileURL)
print("Image ID: \(imageName) saved. Data: \(image)")
} catch let error {
print("error saving file with error", error)
}
}
After this, I want to populate a list, and convert the data back into an Image
for use in a List
:在此之后,我想填充一个列表,并将数据转换回
Image
以在List
使用:
struct ListView: View {
//notification viewmodel class
@EnvironmentObject var vm: ViewModel
@State private var inputImage: UIImage?
@State private var image: Image?
@State private var id: String?
func loadImage() {
guard let inputImage = inputImage else { return }
image = Image(uiImage: inputImage)
}
func loadImageFromDiskWith(fileName: String) -> UIImage? {
let documentDirectory = FileManager.SearchPathDirectory.documentDirectory
let userDomainMask = FileManager.SearchPathDomainMask.userDomainMask
let paths = NSSearchPathForDirectoriesInDomains(documentDirectory, userDomainMask, true)
if let dirPath = paths.first {
let imageUrl = URL(fileURLWithPath: dirPath).appendingPathComponent(fileName)
let image = UIImage(contentsOfFile: imageUrl.path)
return image
}
return nil
}
var body: some View {
NavigationView {
List {
//New row for each item in notification array
ForEach(vm.notificationArray, id: \.content) { notification in
HStack {
VStack(alignment: .leading, spacing: 10) {
//Populate text with info from notification.
Text(notification.content.title)
let id = notification.identifier
//I want to call loadImage here, and show the image if it exists, but there are many errors with this and I can't seem to get it to work
image = Image(uiImage: loadImageFromDiskWith(fileName: id)!)
if image != nil {
image?
.resizable()
.scaledToFit()
} else {
}
}
}
}
}
}
}
}
}
How can I call my load image function and get present the image in the list?如何调用我的加载图像功能并在列表中显示图像? Thank you.
谢谢你。
Try the following尝试以下
VStack(alignment: .leading, spacing: 10) {
//Populate text with info from notification.
Text(notification.content.title)
if let image = loadImageFromDiskWith(fileName: notification.identifier) {
Image(uiImage: image)
.resizable()
.scaledToFit()
} else {
// Put some placeholder image here
}
}
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