生命不止，繼續 go go go !!!

那麼今天就跟大家分享一下，golang中如何操作PDF。

PDF簡介

The Portable Document Format (PDF) is a file format used to present documents in a manner independent of application software, hardware, and operating systems.[3] Each PDF file encapsulates a complete description of a fixed-layout flat document, including the text, fonts, graphics, and other information needed to display it.

pdf（Portable Document Format的簡稱，意為“行動式文件格式”），是由Adobe Systems用於與應用程式、作業系統、硬體無關的方式進行檔案交換所發展出的檔案格式。PDF檔案以PostScript語言圖象模型為基礎，無論在哪種印表機上都可保證精確的顏色和準確的列印效果，即PDF會忠實地再現原稿的每一個字元、顏色以及圖象。

rsc.io/pdf

Star: 202

獲取：

go get rsc.io/pdf

讀取PDF檔案，獲取總頁數

package main

import (
    "fmt"

    "rsc.io/pdf"
)

func
 
 main() {
    file, err := pdf.Open("go.pdf")
    if err != nil {
        panic(err)
    }
    fmt.Println(file.NumPage())
}

讀取某一頁的內容

package main

import (
    "fmt"

    "rsc.io/pdf"
)

func main() {
    file, err := pdf.Open("test.pdf")
    if err != nil {
        panic(err)
    }
    fmt.Println(file.Page(2
 
).Content())
}

jung-kurt/gofpdf

注意：該庫不支援中文！！！

Star: 733

獲取：

go get github.com/jung-kurt/gofpdf

生成PDF文件

package main

import (
    "fmt"

    "github.com/jung-kurt/gofpdf"
)

func main() {
    pdf := gofpdf.New("P", "mm", "A4", "")
    pdf.AddPage()
    pdf.SetFont("Arial", "B", 26)
    pdf.Cell(40, 10, "Hello PDF World")
    err := pdf.OutputFileAndClose("write_pdf.pdf")
    if err != nil {
        fmt.Println(err)
    }
}

生成加密的PDF

package main

import (
    "fmt"

    "github.com/jung-kurt/gofpdf"
)

func main() {
    pdf := gofpdf.New("P", "mm", "A4", "")
    pdf.SetProtection(gofpdf.CnProtectPrint, "123", "abc")
    pdf.AddPage()
    pdf.SetFont("Arial", "", 12)
    pdf.Write(10, "You Must Enter the Password!!!")
    err := pdf.OutputFileAndClose("write_pdf_with_password.pdf")
    if err != nil {
        fmt.Println(err)
    }
}

PDF中插入圖片

package main

import (
    "fmt"

    "github.com/jung-kurt/gofpdf"
)

func main() {
    pdf := gofpdf.New("P", "mm", "A4", "")
    pdf.AddPage()
    pdf.SetFont("Arial", "", 11)
    pdf.Image("test.png", 10, 10, 30, 0, false, "", 0, "")
    pdf.Text(50, 20, "test.png")
    pdf.Image("test.gif", 10, 40, 30, 0, false, "", 0, "")
    pdf.Text(50, 50, "test.gif")
    pdf.Image("test.jpg", 10, 130, 30, 0, false, "", 0, "")
    pdf.Text(50, 140, "test.jpg")

    err := pdf.OutputFileAndClose("write_pdf_with_image.pdf")
    if err != nil {
        fmt.Println(err)
    }
}

PDF中增加連結、HTML

package main

import (
    "fmt"

    "github.com/jung-kurt/gofpdf"
)

func main() {
    pdf := gofpdf.New("P", "mm", "A4", "")
    pdf.AddPage()
    pdf.SetFont("Helvetica", "", 20)
    _, lineHt := pdf.GetFontSize()
    pdf.Write(lineHt, "To find out what's new in this tutorial, click ")
    pdf.SetFont("", "U", 0)
    link := pdf.AddLink()
    pdf.WriteLinkID(lineHt, "here", link)
    pdf.SetFont("", "", 0)
    // Second page: image link and basic HTML with link
    pdf.AddPage()
    pdf.SetLink(link, 0, -1)
    pdf.Image("test.png", 10, 12, 30, 0, false, "", 0, "http://blog.csdn.net/wangshubo1989?viewmode=contents")
    pdf.SetLeftMargin(45)
    pdf.SetFontSize(14)
    _, lineHt = pdf.GetFontSize()
    htmlStr := `You can now easily print text mixing different styles: <b>bold</b>, ` +
        `<i>italic</i>, <u>underlined</u>, or <b><i><u>all at once</u></i></b>!<br><br>` +
        `<center>You can also center text.</center>` +
        `<right>Or align it to the right.</right>` +
        `You can also insert links on text, such as ` +
        `<a href="http://www.fpdf.org">http://blog.csdn.net/wangshubo1989?viewmode=contents</a>, or on an image: click on the logo.`
    html := pdf.HTMLBasicNew()
    html.Write(lineHt, htmlStr)
    err := pdf.OutputFileAndClose("write_html.pdf")
    if err != nil {
        fmt.Println(err)
    }
}

signintech/gopdf

既然jung-kurt/gofpdf不支援中文，那麼就介紹一個支援中文的signintech/gopdf。

Star: 422

獲取：

go get -u github.com/signintech/gopdf

生成PDF檔案

為了炫酷一點，自己從網上下載一個字型。

package main

import (
    "log"

    "github.com/signintech/gopdf"
)

func main() {

    pdf := gopdf.GoPdf{}
    pdf.Start(gopdf.Config{PageSize: gopdf.Rect{W: 595.28, H: 841.89}}) //595.28, 841.89 = A4
    pdf.AddPage()
    err := pdf.AddTTFFont("wts11", "TTENuoJ_0.ttf")
    if err != nil {
        log.Print(err.Error())
        return
    }

    err = pdf.SetFont("wts11", "", 14)
    if err != nil {
        log.Print(err.Error())
        return
    }
    pdf.Cell(nil, "我閉目在經殿的香霧中， 驀然聽見你頌經中的真言；")
    pdf.WritePdf("hello.pdf")

}