iText：PdfContentByte.rectangle（Rectangle）的行为与预期不符 [英] iText: PdfContentByte.rectangle(Rectangle) does not behave as expected

问题描述

我正在使用iText 2.1.7，我试图在我的文档中绘制一个简单的矩形。下面的代码块按预期工作，并绘制一个矩形，覆盖整个页面，不包括页边距。

I am using iText 2.1.7 and I am trying to draw a simple rectangle to my document. The below block of code works as expected and draws a rectangle that covers the entire page not including the page margins.

Document document = new Document(PageSize.A4.rotate());
PdfWriter writer = PdfWriter.getInstance(document, outputStream);
document.open();
PdfContentByte canvas = writer.getDirectContent();
Rectangle pageDimensions = writer.getPageSize();

canvas.saveState();
canvas.rectangle(
        pageDimensions.getLeft(marginLeft),
        pageDimensions.getBottom(marginBottom),
        pageDimensions.getRight(marginRight),
        pageDimensions.getTop(marginTop));
canvas.setColorStroke(Color.BLACK);
canvas.stroke();
canvas.restoreState();

document.close();

但是，如果我略微更改画布代码块，以便我在外面定义矩形PdfContentByte，然后我的代码生成一个空白页。

However, if I change the block of canvas code slightly such that I am defining the rectangle outside of the PdfContentByte, then my code generates a blank page.

...
Rectangle marginBox = new Rectangle(
        pageDimensions.getLeft(marginLeft),
        pageDimensions.getBottom(marginBottom),
        pageDimensions.getRight(marginRight),
        pageDimensions.getTop(marginTop));
canvas.saveState();
canvas.rectangle(marginBox);
canvas.setColorStroke(Color.BLACK);
canvas.stroke();
canvas.restoreState();
...

这不是的预期用途 PdfContentByte.rectangle（Rectangle）方法??理想情况下，我想以一种与directContent没有紧密耦合的方式定义矩形（以及它们的边框颜色和宽度），并且可以在以后将它们添加到directContent中。

Is this not the intended usage of the PdfContentByte.rectangle(Rectangle) method?? Ideally, I would like define Rectangles (along with their border colors and widths) in a way that is not so tightly coupled with the directContent and have the freedom to add them to the directContent at a later point.

推荐答案

首先，我觉得有必要说你正在使用你不应再使用的iText版本。有关详细信息，请参见 http://itextpdf.com/salesfaq 。

First, I feel obliged to say that you're using a version of iText you should no longer use. See http://itextpdf.com/salesfaq for more info.

至于你的问题，你做了一些错误的假设。例如：当你使用 Rectangle 对象时，使用 stroke（）运算符没有意义，因为 rectangle（）采用 Rectangle 作为参数描边路径的方法（与采用4 <$ c的方法相反） $ c> float values）。

As for your question, you are making some assumptions that are wrong. For instance: when you use the Rectangle object, using the stroke() operator doesn't make sense as the rectangle() method that takes a Rectangle as parameter strokes the path (as opposed to the method that takes 4 float values).

// This draws and strokes the path:
canvas.rectangle(marginBox);
// There is no path to stroke anymore:
canvas.setColorStroke(Color.BLACK);
canvas.stroke();

矩形（）方法如果没有为 Rectangle 定义边框和边框宽度， Rectangle 将不会执行任何操作。换句话说，你需要这样的东西：

The rectangle() method that takes a Rectangle won't do anything if no border and no border width have been defined for the Rectangle. In other words, you need something like this:

Rectangle rect = new Rectangle(36, 36, 559, 806);
rect.setBorder(Rectangle.BOX);
rect.setBorderWidth(2);
canvas.rectangle(rect);

如果没有定义边界，边界的宽度也不大于0，则假设存在没有边界。

If no borders are defined, nor a width greater than 0 for the border, it is assumed that there is no border.

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