安全pdf:已锁定/不可编辑，以防止从iOS设备生成后进行更改 [英] secure pdf : locked/uneditable to prevent changes after generating from iOS device

问题描述

我正在使用UIKit Framework在iOS设备中生成pdf. 我想知道我们是否可以锁定(提供安全性)生成的pdf，以便在通过电子邮件发送或下载后无法使用任何pdf可编辑工具进行编辑/修改.

I am using UIKit Framework to generate pdf in iOS device. I am wondering if we can lock (provide security) to the generated pdf so that after emailing or downloading it , one can not edit/modify using any pdf editable tool.

推荐答案

是的-这是可能的.如果使用UIGraphicsBeginPDFContextToFile开始创建PDF，则可以向其发送带有选项的字典，以指定所需的加密/锁定类型.这是它的文档:

Yes - this is possible. If you start the creation of a PDF with UIGraphicsBeginPDFContextToFile you can then send a dictionary to it with options to specify what kind of encryption/locking you want. Here is the documentation for it:

http://developer.apple .com/library/ios/#documentation/uikit/reference/UIKitFunctionReference/Reference/reference.html

这是创建它的示例:

NSDictionary * pdfInfo = nil;

if (trimmedPassPhrase && [trimmedPassPhrase length] > 0) {
    pdfInfo = [NSDictionary dictionaryWithObjectsAndKeys:trimmedPassPhrase, kCGPDFContextOwnerPassword,
               trimmedPassPhrase, kCGPDFContextUserPassword,
               [NSNumber numberWithInt:128], kCGPDFContextEncryptionKeyLength, nil];
}


BOOL pdfContextSuccess =  UIGraphicsBeginPDFContextToFile(newFilePath, CGRectZero, pdfInfo  );

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