如何以编程方式在iOS中创建PDF?

时间:2011-10-21 09:43:32

标签: objective-c ios ios4 pdf-generation pdf-viewer

我想在iOS中创建一个PDF文件,PDF中应该有一个表,它从一个数组中填充。我已经在Google上搜索过,但没有成功。任何帮助表示赞赏

1 个答案:

答案 0 :(得分:1)

像渲染文本的例程:

- (CFRange)renderTextRange:(CFRange)currentRange andFrameSetter:(CTFramesetterRef)frameSetter intoRect:(CGRect)frameRect {
CGMutablePathRef framePath = CGPathCreateMutable();
CGPathAddRect(framePath, NULL, frameRect);
CTFrameRef frameRef = CTFramesetterCreateFrame(frameSetter, currentRange, framePath, NULL);
CGContextRef currentContext = UIGraphicsGetCurrentContext();
CGContextSaveGState(currentContext);
CGContextSetTextMatrix(currentContext, CGAffineTransformIdentity);  
CGContextTranslateCTM(currentContext, 0, 792); 
CGContextScaleCTM(currentContext, 1.0, -1.0);
CTFrameDraw(frameRef, currentContext);
CGContextRestoreGState(currentContext);
CGPathRelease(framePath);
currentRange = CTFrameGetVisibleStringRange(frameRef);
currentRange.location += currentRange.length;
currentRange.length = 0;
CFRelease(frameRef);
return currentRange;
}

以下代码片段调用它,假设您在相应的变量中创建了上下文和任何字体等。以下循环只是将文本逐行构建到NSMutableAttributedString中,然后可以呈现:

CTFontRef splainFont = CTFontCreateWithName(CFSTR("Helvetica"), 10.0f, NULL);
CGFloat margin = 32.0f;
CGFloat sink = 8.0f;

NSMutableAttributedString *mainAttributedString = [[NSMutableAttributedString alloc] init];
NSMutableString *mainString = [[NSMutableString alloc] init];

// Ingredients is an NSArray of NSDictionaries
// But yours could be anything, or just an array of text.
for (Ingredient *ingredient in ingredients) {
    NSString *ingredientText = [NSString stringWithFormat:@"%@\t%@
        \n",ingredient.amount,ingredient.name];
    [mainString appendString:ingredientText];
    NSMutableAttributedString *ingredientAttributedText =
        [[NSMutableAttributedString alloc] initWithString:ingredientText];
    [ingredientAttributedText addAttribute:(NSString *)(kCTFontAttributeName)
        value:(id)splainFont
        range:NSMakeRange(0, [ingredientText length])];
    [mainAttributedString appendAttributedString:ingredientAttributedText];
    [ingredientAttributedText release];
}

现在你已经用一行NSMutableAttributedString的新行写出了你的数组,你可以渲染它,这取决于你可能想要在循环中渲染出来的文本,直到渲染的位置与你的文本长度相匹配。类似的东西:

// Render Main text.
CTFramesetterRef mainSetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)mainAttributedString);
currentRange = [KookaDIS renderTextRange:currentRange 
    andFrameSetter:mainSetter 
    intoRect:pageRect];

// If not finished create new page and loop until we are.
while (!done) {
    UIGraphicsBeginPDFPageWithInfo(pageRect, nil);

    currentRange = [self renderTextRange:currentRange 
        andFrameSetter:mainSetter 
        intoRect:pageRect];

    if (currentRange.location >= [mainString length]) {
        done = TRUE;
    }
}

上面的代码需要相当多的调整我确定,因为它被我自己的项目破解,所以一些变量(如框架设置器)将不存在,你需要关闭PDF上下文和注意如何使用mainString来确定文本何时被渲染出来。

它应该清楚地表明如何循环数组或任何其他组以将任意长度的文本呈现到文档中。

稍微修改while循环和输入之前的渲染将允许您在多列中渲染文本。