生成pdf格式并附加数据

Question

我想能够从Android应用程序生成一个考勤表。考勤表格式如下图所示。我从firebase数据库中获取数据（示例50200）。有更多相同的数据（50200），我需要在其余的框中附加。

这就是我从firebase获取StudentIds数据的方法。我只想将这些学生ID以这些格式编写到pdf中。

    if (dataSnapshot.exists()) {
                RVStudent.setVisibility(View.VISIBLE);
                EmptyViewStudent.setVisibility(View.GONE);

                int i = 1;
                for (DataSnapshot dataSnapshot1 : dataSnapshot.child(userID).child("Course").child(CourseCode).child("Students").getChildren()) {
                    studentId[i]= dataSnapshot1.getKey();
                    studentName[i]=dataSnapshot.child(userID).child("Course").child(CourseCode).child("Students").child(studentId[i]).child("StudentName").getValue(String.class);
                    studentserial[i]= String.valueOf(i);

                    listStudent.add(new StudentModel(studentId[i],studentName[i], studentserial[i],CourseCode,CourseName, UserProfileImageUrl));
                    i++;
                }

                if(listStudent.size()==0){
                    RVStudent.setVisibility(View.GONE);
                    EmptyViewStudent.setVisibility(View.VISIBLE);
                }


            }else{
                RVStudent.setVisibility(View.GONE);
                EmptyViewStudent.setVisibility(View.VISIBLE);
            }

我尝试了我的RecyclerView它有点工作，但没有提供所需的结果和pdf在某种程度上看起来很奇怪，因为它是RecyclerView的截图。除了使用RecyclerView生成它之外，pdf视图会改变设备到设备。这是正确的做法。

Answer 1

我在阅读了ITEXT文件后找到了解决方案。虽然我不知道它是否是最佳方式，但它对我来说非常有用。

 public void onDataChange(DataSnapshot dataSnapshot) {
            String studentId[] = new String[50];

            listStudentId.clear();
            if (dataSnapshot.exists()) {
             //   EmptyViewStudent.setVisibility(View.GONE);
                int i = 1;
                for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
                    studentId[i]= dataSnapshot1.getKey();
                    listStudentId.add(new StudentIdModel(studentId[i]));
                    i++;
                }

                if(listStudentId.size()==0){

                }
            }else{

            }

            try {
                Document document = new Document();
                File root = new File(Environment.getExternalStorageDirectory(),
                        "/sams_images/AttendanceSheet");
                root.mkdir();
                String sdcardhtmlpath = root.getPath().toString() + "/"+CourseCode+ ".pdf";
                PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(sdcardhtmlpath));

                document.open();
                PdfContentByte canvas = writer.getDirectContent();
                ColumnText ct = new ColumnText(canvas);
                ct.setSimpleColumn(200,750,400,780);
                String documentTitle = CourseCode + " " + CourseName;
                Paragraph paragraph = new Paragraph(new Phrase(2,documentTitle, FontFactory.getFont(FontFactory.TIMES_BOLD, 15)));//add ur string here
                ct.addElement(paragraph);
                ct.setAlignment(Element.ALIGN_CENTER);
                ct.go();

                writeData(writer, document);

            } catch (Exception e) {
                Log.v("PDFcreation", e.toString());
            }

        }

然后我实现了一个循环，将逐个创建每一组视图..

public void writeData(PdfWriter writer, Document document) throws DocumentException {

    int lrectllx = 70;
    int lrectlly = 720;
    int lrecturx = 280;
    int lrectury = 750;

    int rrectllx = 320;
    int rrectlly = 720;
    int rrecturx = 530;
    int rrectury = 750;

    String StudentId[] = new String[50];

    double cr= 9.50;

    for(int i=0; i<listStudentId.size(); i++){

        /* if dataIndex [i] is even number will create box at left side and for odd number create box at right side*/

        if (i%2 == 0){
            PdfContentByte canvas = writer.getDirectContent();
            /*-------------------------- Creating circle -------------------------------------*/
            canvas.circle(lrecturx- 30, (lrectlly+lrectury)/2, cr);
            canvas.setColorStroke(BaseColor.BLACK);

            /*-------------------------- Creating Rectangle -------------------------------------*/
            Rectangle rectangle = new Rectangle(lrectllx, lrectlly, lrecturx, lrectury);
            rectangle.setBorder(Rectangle.BOX);
            canvas.setColorStroke(BaseColor.BLACK);
            rectangle.setBorderWidth(1);
            canvas.rectangle(rectangle);

            /*--------------------------- Appending Text -------------------------------------*/
            ColumnText ct = new ColumnText(canvas);
            ct.setSimpleColumn(rectangle);
            StudentId[i] = listStudentId.get(i).getStudentId();
            Paragraph studentid = new Paragraph(new Phrase(20,StudentId[i], FontFactory.getFont(FontFactory.TIMES, 15)));//add ur string here
            studentid.setAlignment(Element.ALIGN_LEFT);
            studentid.setIndentationLeft(20);
            ct.addElement(studentid);
            ct.go();

            lrectlly = lrectlly - 42;
            lrectury = lrectury - 42;
           // lcx = lrecturx- 30 ;
           // lcy = (lrectlly+lrectury)/2;

        }else{
            PdfContentByte canvas = writer.getDirectContent();

            /*-------------------------- Creating circle -------------------------------------*/
            canvas.circle(rrecturx- 30, (rrectlly+rrectury)/2, cr);
            canvas.setColorStroke(BaseColor.BLACK);

            /*-------------------------- Creating Rectangle -------------------------------------*/
            Rectangle rectangle = new Rectangle(rrectllx, rrectlly, rrecturx, rrectury);
            rectangle.setBorder(Rectangle.BOX);
            rectangle.setBorderWidth(1);
            canvas.setColorStroke(BaseColor.BLACK);
            canvas.rectangle(rectangle);

            /*-------------------------- Appending Text ---------------------------------------*/
            ColumnText ct = new ColumnText(canvas);
            ct.setSimpleColumn(rectangle);
            StudentId[i] = listStudentId.get(i).getStudentId();
            Paragraph studentid = new Paragraph(new Phrase(20,StudentId[i], FontFactory.getFont(FontFactory.TIMES, 15)));//add ur string here
            studentid.setAlignment(Element.ALIGN_LEFT);
            studentid.setIndentationLeft(20);
            ct.addElement(studentid);
            ct.go();

            rrectlly = rrectlly - 42;
            rrectury = rrectury - 42;
        //    rcx = rrecturx- 30 ;
        //    rcy = (rrectlly+rrectury)/2;
        }
    }

    document.close();

}

最后这是我得到的pdf文件..

我相信这将有助于尝试从Android设备格式化pdf文件或使用其他语言创建具有特定格式的pdf文件的人数。问候......每个人。