小编Adi*_*ale的帖子

我的代码如下.我得到的错误是

断言失败:(s-> stack-> next!= NULL),函数CGGStackRestore,文件Context/CGGStack.c,第116行.

码:

 CGPDFPageRef page = CGPDFDocumentGetPage(document, i+1);
            CGRect pageRect = CGPDFPageGetBoxRect(page, kCGPDFMediaBox);
            CGFloat pdfScale = width/pageRect.size.width;
            pageRect.size = CGSizeMake(pageRect.size.width*pdfScale, pageRect.size.height*pdfScale);  
            pageRect.origin = CGPointZero;
            UIGraphicsBeginImageContext(pageRect.size);
            CGContextRef context = UIGraphicsGetCurrentContext();   

            // White BG  CGContextSetRGBFillColor(context, 1.0,1.0,1.0,1.0);  CGContextFillRect(context,pageRect);   CGContextSaveGState(context); 

            CGContextTranslateCTM(context, 0.0, pageRect.size.height);
            CGContextScaleCTM(context, 1.0, -1.0);
            CGContextConcatCTM(context, CGPDFPageGetDrawingTransform(page, kCGPDFMediaBox, pageRect, 0, true));
            CGContextDrawPDFPage(context, page);  
            CGContextRestoreGState(context); 

            UIImage *thm = UIGraphicsGetImageFromCurrentImageContext();
            UIGraphicsEndImageContext(); 
            NSLog(@"Image %@",thm);
            pdfImage = [[UIImageView alloc] initWithImage:thm];
            NSLog(@"Image View: %@",pdfImage);
            [self.view addSubview:pdfImage];
            [self.view reloadInputViews
];

请帮忙.

这段代码不起作用,我不明白这个错误.请帮忙.

   -(UIImage *)addText:(UIImage *)img text:(NSString *)text1
    {    
        int w = img.size.width;
        int h = img.size.height; 
        //lon = h - lon;
        char* text  = (char *)[text1 cStringUsingEncoding:NSASCIIStringEncoding];
        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

        /*UIGraphicsBeginImageContext(self.view.bounds.size);
        [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
        CGContextShowTextAtPoint(UIGraphicsGetCurrentContext(), 50, 100, text, strlen(text));
        UIImage *viewImage =UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        NSLog(@"View Image : %@",viewImage);*/

        CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);
        CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage);
        CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1);

        //char* text    = (char *)[text1 cStringUsingEncoding:NSASCIIStringEncoding];// "05/05/09";
        CGContextSelectFont(context, "Arial", 18, kCGEncodingMacRoman); …

我想使用AESEncryption在Iphone中加密和解密文件.它适用于NSData.但是如果我把数据放在块中,我的文件就会变得很好.我该怎么做呢.我能够使用commoncrypto库加密和解密数据.但是当我尝试以块的形式读取数据时会出现问题.

先感谢您.请帮忙.我需要尽快实现.