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ios - Swift iOS 如何将字节转换为图像

问题描述

我正在尝试从 postgres 检索和可视化图像到 iOS，我尝试变成 Data，然后变成 UIImage，但没有运气，当我创建 UIImage 时它返回 nil。如下图所示，我从 db 中获取了带有双反斜杠和 x 的字符串，这应该是正常的，我尝试保留转义符号并修剪它们，我还尝试使用两者初始化数据带有 byte: 和 base64Encoded 的初始化程序，有和没有选项，但图像始终为零。 来自xcode的截图

func dataToImage(data:String)->Image{
    var imageData = Data(bytes: "68747470733a2f2f73332e65752d63656e7472616c2d312e616d617a6f6e6177732e636f6d2f696c6172696f73616c6174696e6f2f31423236303332462d363935422d344342432d393733412d3342413936343841334535372d373136312d303030303145323833464643303541442e6a706567", count: data.count)
    var base64data = Data(base64Encoded: "68747470733a2f2f73332e65752d63656e7472616c2d312e616d617a6f6e6177732e636f6d2f696c6172696f73616c6174696e6f2f31423236303332462d363935422d344342432d393733412d3342413936343841334535372d373136312d303030303145323833464643303541442e6a706567", options: .ignoreUnknownCharacters)
    return Image(uiImage: UIImage(data: imageData)!)
}

我从数据库得到的字符串：

data    String  "\\x68747470733a2f2f73332e65752d63656e7472616c2d312e616d617a6f6e6177732e636f6d2f696c6172696f73616c6174696e6f2f31423236303332462d363935422d344342432d393733412d3342413936343841334535372d373136312d303030303145323833464643303541442e6a706567"

任何帮助表示赞赏，谢谢！

标签： iosswiftxcodepostgresqlgraphql

解决方案

您没有正确保存图像数据 =/

要正确获取 UIImage 数据，您应该：

let data = yourImage.jpegData(compressionQuality: 1)

它将返回一个数据

因此，将其保存为字符串并准备就绪！

要从数据中设置图像，如下所示：

let data = Data(base64Encoded: myString)
let newImage = UIImage(data: data)

要更轻松地调试，请使用此字符串转换为数据和图像。这个字符串正确地为我们提供了一个数据和一个图像

"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"

我希望它对你有帮助！干杯

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