Java 如何将android中TextView中的值导出为pdf？我尝试过一些方法，但它就像截图的布局和保存为pdf格式

我正在尝试使用android studio开发一个android应用程序，我需要将textview中的文本导出为PDF文档。如果文本较长，PDF文档应自动增加页数。我希望你能理解我

实现这一目标的最佳方式是什么

有内置的图书馆吗？ 或者我该怎么办

这就是我所尝试的：

活动\u main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffffff"
android:orientation="vertical">

<Button
    android:id="@+id/btn_generate"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Generate PDF" />

<LinearLayout
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:id="@+id/ll_pdflayout"
    android:background="#ffffff"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/iv_image"
        android:src="@drawable/image"
        android:layout_width="300dp"
        android:scaleType="fitXY"
        android:layout_marginTop="10dp"
        android:layout_gravity="center"
        android:layout_height="250dp" />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="14dp"
        android:text="Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum."
        android:layout_marginTop="10dp"
        android:gravity="center"
        android:paddingLeft="10dp"
        android:paddingRight="10dp"
        android:textColor="#000000"/>


    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tv_link"
        android:textSize="10dp"
        android:textColor="#000000"/>


</LinearLayout>

}

这是@Deepshikha Puri在本文中的回答

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

Button btn_generate;
TextView tv_link;
ImageView iv_image;
LinearLayout ll_pdflayout;
public static int REQUEST_PERMISSIONS = 1;
boolean boolean_permission;
boolean boolean_save;
Bitmap bitmap;
ProgressDialog progressDialog;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    init();
    fn_permission();
    listener();
}


private void init(){
    btn_generate = (Button)findViewById(R.id.btn_generate);
    tv_link = (TextView)findViewById(R.id.tv_link);
    iv_image = (ImageView) findViewById(R.id.iv_image);
    ll_pdflayout = (LinearLayout) findViewById(R.id.ll_pdflayout);

}

private void listener(){
    btn_generate.setOnClickListener(this);
}

@Override
public void onClick(View view) {

    switch (view.getId()) {
        case R.id.btn_generate:

            if (boolean_save) {
                Intent intent = new Intent(getApplicationContext(), PDFViewActivity.class);
                startActivity(intent);

            } else {
                if (boolean_permission) {
                    progressDialog = new ProgressDialog(MainActivity.this);
                    progressDialog.setMessage("Please wait");
                     bitmap = loadBitmapFromView(ll_pdflayout, ll_pdflayout.getWidth(), ll_pdflayout.getHeight());
                    createPdf();
                } else {

                }

                createPdf();
                break;
            }
    }
}



private void createPdf(){
    WindowManager wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
    Display display = wm.getDefaultDisplay();
    DisplayMetrics displaymetrics = new DisplayMetrics();
    this.getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
    float hight = displaymetrics.heightPixels ;
    float width = displaymetrics.widthPixels ;

    int convertHighet = (int) hight, convertWidth = (int) width;

    PdfDocument document = new PdfDocument();
    PdfDocument.PageInfo pageInfo = new PdfDocument.PageInfo.Builder(convertWidth, convertHighet, 1).create();
    PdfDocument.Page page = document.startPage(pageInfo);

    Canvas canvas = page.getCanvas();


    Paint paint = new Paint();
    canvas.drawPaint(paint);


    bitmap = Bitmap.createScaledBitmap(bitmap, convertWidth, convertHighet, true);

    paint.setColor(Color.BLUE);
    canvas.drawBitmap(bitmap, 0, 0 , null);
    document.finishPage(page);


   String path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).toString() + "/PdfTett/";
File dir = new File(path);
if (!dir.exists())
    dir.mkdirs();

File filePath = new File(dir,"Testtt.pdf");

    try {
        document.writeTo(new FileOutputStream(filePath));
        btn_generate.setText("Check PDF");
        boolean_save=true;
    } catch (IOException e) {
        e.printStackTrace();
        Toast.makeText(this, "Something wrong: " + e.toString(), Toast.LENGTH_LONG).show();
    }

    // close the document
    document.close();
}



public static Bitmap loadBitmapFromView(View v, int width, int height) {
    Bitmap b = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(b);
    v.draw(c);

    return b;
}

private void fn_permission() {
    if ((ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)||
            (ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)) {

        if ((ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, android.Manifest.permission.READ_EXTERNAL_STORAGE))) {
        } else {
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{android.Manifest.permission.READ_EXTERNAL_STORAGE},
                    REQUEST_PERMISSIONS);

        }

        if ((ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE))) {
        } else {
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                    REQUEST_PERMISSIONS);

        }
    } else {
        boolean_permission = true;


    }
}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode == REQUEST_PERMISSIONS) {

        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

            boolean_permission = true;


        } else {
            Toast.makeText(getApplicationContext(), "Please allow the permission", Toast.LENGTH_LONG).show();

        }
    }
}