Itext更改书签缩放级别以继承现有pdf的缩放 [英] Itext change bookmarks zoom level to inherit zoom in existing pdf

问题描述

使用 iText5 PDF库，我能够在PDF中读取书签。现在我想使用iText在现有PDF中更改书签的缩放级别（继承缩放）。
是否可以使用iText PDF库，以及如何使用？

Using the iText5 PDF library, I am able to read bookmarks exist in PDF. Now I want to change the zoom level of bookmarks (Inherit zoom) in existing PDF using iText. Is it possible using the iText PDF library, and how?

我附上了截图。

I have attached a screenshot.

这个是我用来更改书签缩放级别的代码（根据@lowagie评论）：

This is the code I am using to change the bookmark zoom level (as per @lowagie comment):

public void changeList(List<HashMap<String, Object>> list) {
        for (HashMap<String, Object> entry : list) {
            for (String key : entry.keySet()) {
                System.out.println(key);

                if ("Kids".equals(key)) {
                    Object o = entry.get(key);
                    changeList((List<HashMap<String, Object>>) o);
                } else if ("Page".equals(key)) {
                    String dest = (String) entry.get(key);
                    entry.put("Page", dest.replaceAll("Fit", "XYZ 30 100 0"));
                }
            }
        }
    }

书签树形结构：

Bookmark Tree Structure :

推荐答案

请看看我对以下问题的回答：将继承缩放（动作属性）设置为pdf文件中的书签

Please take a look at my answer to the following question: Set inherit Zoom(action property) to bookmark in the pdf file

在该答案中，我读了使用 SimpleBookmark 对象的书签。这可能与您阅读书签的方式相同。结果是 List 的 HashMap 对象，它们代表一个大纲树。我使用递归方法查找所有Page条目。

In that answer, I read bookmarks using the SimpleBookmark object. That's probably the same way you are reading bookmarks. The result is a List of HashMap objects that represents an outline tree. I use a recursive method to find all the "Page" entries.

这些页面条目包含目的地，实例适合， FitH ， XYZ ，...你需要将所有这些引用更改为 XYZ 引用，其中您将缩放系数设置为0.缩放系数0相当于继承缩放。

These page entries contain a destination, for instance Fit, FitH, XYZ,... You need to change all these references into XYZ references of which you set the zoom factor to 0. A zoom factor 0 is the equivalent of 'Inherit Zoom'.

在回答将继承缩放（动作属性）设置为pdf文件中的书签我有以下代码：

public void changeList(List<HashMap<String, Object>> list) {
    for (HashMap<String, Object> entry : list) {
        for (String key : entry.keySet()) {
            if ("Kids".equals(key)) {
                Object o = entry.get(key);
                changeList((List<HashMap<String, Object>>)o);
            }
            else if ("Page".equals(key)) {
                String dest = (String)entry.get(key);
                entry.put("Page", dest.replaceAll("Fit", "FitV 60"));
            }
        }
    }
}

这是很明显，您可以通过全新的操作替换任何现有的页面操作。例如：

It's obvious that you can replace any existing "Page" action by a completely new action. For instance:

entry.put("Page", "XYZ 30 100 0");

现在，您将使用继承的缩放系数跳转到页面上的坐标30 100。如果要放大其他部分，例如与原始位置或多或少对应的位置，则需要检查原始位置中 FitR 之后的坐标PDF。有4：左下x，左下y，右上x和右上y坐标。您可以使用这些值的原始目标解析字符串，并将这些坐标中的两个重新用作 XYZ 目标中的X和Y值。

Now you'll jump to the coordinate 30 100 on the page with an inherited zoom factor. If you want to zoom in on another part, for instance a location that corresponds more or less with the original location, you need to examine the coordinates that followed the FitR in your original PDF. There are 4: the lower-left x, lower-left y, upper-right x and upper-right y coordinate. You could parse the string with the original destination for those values and reuse two of these coordinates as your X and Y values in the XYZ destination.

与XYZ目的地一起传递的XY坐标是左上角的坐标。例如，如果你有 FitR -3 234 486 627 ，那么你放大一个坐标为llx = -3，lly = 234，urx = 486和ury =的矩形627（ll指的是左下角; ur指的是右上角）。左上角是llx，或者在你的情况下x = -3和y = 627.简而言之：在这种情况下，你需要XYZ -3 627 0。

The X Y coordinate passed with the XYZ destination is the coordinate of the top-left corner. For instance, if you have FitR -3 234 486 627, then you zoom in on a rectangle with coordinates llx = -3, lly = 234, urx = 486 and ury = 627 (ll refers to lower-left; ur refers to upper-right). The top left corner is llx,ury or in your case x = -3 and y = 627. In short: in this case, you'd need "XYZ -3 627 0".

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