如何在 Swift 中从 .writetoFile 恢复 PDF [英] How to recover PDF's from .writetoFile in Swift
本文介绍了如何在 Swift 中从 .writetoFile 恢复 PDF的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我正在使用 .writetofile 保存图像,但我不知道如何恢复它.这是我保存图像的方式:
I'm saving an image using .writetofile but I don't know how to recover it. This how I save the image:
self.pdfData.writeToURL(NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first!.URLByAppendingPathComponent("testgogo.pdf"), atomically: true) // what it is saved as
self.pdfData.writeToFile("tessst.pdf", atomically: false)
print(NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask).first!.path!)
var pdfData: NSData {
let result = NSMutableData()
UIGraphicsBeginPDFContextToData(result, frame, nil)
guard let context = UIGraphicsGetCurrentContext()
else { return result }
UIGraphicsBeginPDFPage()
layer.renderInContext(context)
UIGraphicsEndPDFContext()
return result
}
我以后如何取回图像?
推荐答案
这里有一个示例,说明如何在 Swift 2.x 中执行此操作.
Here is an example of how you could do it in Swift 2.x.
它使用 NSData(contentsOfFile: myFilePath)
来加载文件.该示例使用 PNG 文件.
It uses the NSData(contentsOfFile: myFilePath)
to load the file.
The example uses a PNG file.
直接从我的游乐场:
import UIKit
/*
* Creates an UIImage from a UIView
*/
func createImage(fromView view: UIView) -> UIImage {
UIGraphicsBeginImageContext(view.frame.size)
let context = UIGraphicsGetCurrentContext()
view.layer.renderInContext(context!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext();
return image
}
/*
* Finds the path in Document folder
*/
func createMyFilePath(forFileName fileName: String) -> String? {
let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory,.UserDomainMask,true)
if let path = paths.first {
return path + "/\(fileName)"
}
return nil
}
/*
* Main behaviour
*/
// ImageView with Label on it
let imageView = UIImageView(image: UIImage(named: "borat"))
let label = UILabel(frame: imageView.frame)
label.font = UIFont(name: "helvetica", size: 40)
label.text = "Great Success!"
imageView .addSubview(label)
// Find the path where to save
guard let myFilePath = createMyFilePath(forFileName: "borat-with-label.png") else {
print("Cannot generate file path ☹️")
exit(0)
}
// Use this to check in finder where your file is saved
print(myFilePath)
// Transform the imageView in UIImage to save it
let imageToSave = createImage(fromView: imageView)
// Get the image as data
guard let imageToSaveAsData = UIImagePNGRepresentation(imageToSave) else {
print("Cannot transform image to data ☹️")
exit(1)
}
// Save to Disk!
do{
try imageToSaveAsData.writeToFile(myFilePath, options: .DataWritingAtomic)
} catch {
print("Error, cannot write to the location \(myFilePath)")
}
// Load from Disk!
let loadedImageData = NSData(contentsOfFile: myFilePath)
// Check the data is the same
if loadedImageData == imageToSaveAsData {
print("✌️")
}
// Have a look at the loaded image!
UIImage(data: loadedImageData!)
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