iphone - 如何使用 NSData 或使用数据字节 objective-c 生成 pdf？

Question

您好，我想使用 NSData 或使用 webservice 提供的数据字节来编写 pdf？

    -(NSData *)saveData:(NSData*)fileData fileName:(NSString *)fileName fileType:(NSString *)fileType
{
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
    NSString *documentsDir = [paths objectAtIndex:0];

    NSString *filePath = [NSString stringWithFormat:@"%@/%@.%@",documentsDir,fileName,fileType];

    NSData* downloadData = [NSData dataWithData:fileData];

    [fileManager createFileAtPath:filePath contents:downloadData attributes:nil];


}

我正在使用它，但它不起作用，它给我错误“它可能已损坏或使用预览无法识别的文件格式。”打开由上述代码创建的 pdf。

Answer 1

您可以使用下面的代码将 NSData 转换为 PDF...我从 This link 得到下面的代码

NSString *string=[NSString stringWithFormat:@"%@.pdf",[yourArray objectAtIndex:pageIndex]];
[controller1 addAttachmentData:pdfData mimeType:@"application/pdf" fileName:string];
[self presentModalViewController:controller1 animated:YES];
[controller1 release];

//to convert pdf to NSData
NSString *pdfPath = [documentsDirectory stringByAppendingPathComponent:@"test.pdf"];
NSData *myData = [NSData dataWithContentsOfFile:pdfPath];

//to convert NSData to pdf
NSData *data               = //some nsdata
CFDataRef myPDFData        = (CFDataRef)data;
CGDataProviderRef provider = CGDataProviderCreateWithCFData(myPDFData);
CGPDFDocumentRef pdf       = CGPDFDocumentCreateWithProvider(provider);

-(IBAction)saveasPDF:(id)sender{
     NSString *string=[NSString stringWithFormat:@"%@.pdf",[yourArray objectAtIndex:pageIndex]];
     [controller1 addAttachmentData:pdfData mimeType:@"application/pdf" fileName:string];
     [self presentModalViewController:controller1 animated:YES];
     [pdfData writeToFile:[self getDBPathPDf:string] atomically:YES];
}

-(NSString *) getDBPathPDf:(NSString *)PdfName {
       NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
       NSString *documentsDir = [paths objectAtIndex:0];
        return [documentsDir stringByAppendingPathComponent:PdfName];
}

---

总结:从pdf文件路径获取NSData

NSData *pdfData = [NSData dataWithContentsOfFile:pathToFile1];
NSLog(@"pdfData= %d", pdfData != nil);

将NSData写入pdf文件

[pdfData writeToFile:pathToFile2 atomically:YES];