android开发打印票据或文档的方法：android打印文档的类

最近在做个一个基于android平台的工厂ERP项目，需要用到android平板连接打印机打印文档的功能。经过在网上一顿狂搜之后，发现目前好像打印机对android的直接没有任何标准， 再不就是自家封的API，再不就是直接调用ESC/POS命令，通过调用打印函数来打印。 如果直接使用ESC/POS命令，这个到是通用，但是调用打印机指令进行走纸、扫点这个开发成本有点高。如果调用打印机的API，那么如果有N个项目，客户采购N种不同的打印机，我们就要实现N套打印程序。

       针对以上的情况，是否可以通过图片或者PDF等通用格式进行打印呢？好吧，我们使用android自带的xml编辑器来生成layout，在程序里通过layout给控件赋值，之后把layout生成view，转化成图片。再通过打印机提供的厂商提供的图片打印API来实现单据的打印。这个程序目前可以把xml转化为图片并保存到本地，由于没有真机，无法进行打印测试。但按照市场调研，目前市面的热敏打印机都支持图片打印。下面附上源码：

 

打印工具类

public class PrintUtil {

 private static final String TAG = "PrintUtil";

 public String SCREEN_SHOTS_LOCATION = Environment
   .getExternalStorageDirectory().getPath();
 /**
  * 对当前view进行截屏，并保存到SCREEN_SHOTS_LOCATION指定的目录下
  * @param view
  * @param name
  * @return
  * @throws Exception
  */
 public void takeScreenShot(View view, String name,TakeScreenShotCallBack callback) throws Exception{
  takeScreenShot(view,name,SCREEN_SHOTS_LOCATION,callback);
 }

 TakeScreenShotCallBack mCallback = new TakeScreenShotCallBack(){
  @Override
  public void excute(File file) {
   // TODO Auto-generated method stub

  }

 };


 /**
  * 把传入的view保存为图片
  * @param parent 事件触发视图，可以是button等
  * @param view 保存为图片的视图
  * @param isShow 是否显示展示视图
  * @return
  */
 public void shotViewAsImage(View parent,View view, boolean isShow){
  PopupWindow popupWindow = getPopuptWindow(view);
  if(isShow)
   popupWindow.showAtLocation(parent, Gravity.CENTER, 0, 0);
  File newFile = null;
  try {
   takeScreenShot(popupWindow.getContentView(),null,mCallback);
  } catch (Exception e) {
   Log.e(TAG, e.getMessage());
  }
 }

 /**
  * 创建popupWindow
  * @param popupWindow_view
  * @return
  */
 protected PopupWindow getPopuptWindow(View popupWindow_view) {
  PopupWindow popupWindow = null;
  popupWindow = new PopupWindow(popupWindow_view, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT, true);// 创建PopupWindow实例
  popupWindow.setBackgroundDrawable(new BitmapDrawable());
  popupWindow.setFocusable(true);
  popupWindow.setOutsideTouchable(false);
  return popupWindow;
 }

 public interface TakeScreenShotCallBack{
  public void excute(File file);
 }

 /**
  * 对当前view进行截屏，并保存到path指定的目录下
  * @param view
  * @param name
  * @param path
  * @return
  * @throws Exception
  */
 public void takeScreenShot(final View view, final String name,final String path,final TakeScreenShotCallBack callback) throws Exception {



  final Bitmap bitmap = convertViewToBitmap(view);
  Runnable runnable = new Runnable() {
   @Override
   public void run() {

    Canvas canvas = new Canvas(bitmap);
    int w = bitmap.getWidth();
    int h = bitmap.getHeight();
    Paint paint = new Paint();
    paint.setColor(Color.YELLOW);
    String n = null;
    if(null == name || "".equals(name)){
     SimpleDateFormat simple = new SimpleDateFormat("yyyyMMddhhmmss");
     n = simple.format(new Date());
    }else{
     n = name;
    }
    canvas.drawText("", w - w / 2, h - h / 10, paint);
    canvas.save();
    canvas.restore();
    FileOutputStream fos = null;
    File file = null;
    try {
     File sddir = new File(path);
     if (!sddir.exists()) {
      sddir.mkdirs();
     }
     //生成以时间为名称的文件
     file = new File(path + File.separator
       + n + ".png");
     fos = new FileOutputStream(file);
     if (fos != null) {
      bitmap.compress(Bitmap.CompressFormat.PNG, 90, fos);
      fos.close();
     }
    } catch (Exception e) {
     Log.e(TAG, e.getMessage(),e);
    }
    callback.excute(file);
   }
  };
  Thread thread = new Thread(runnable);
  thread.start();

 }

 /**
  * 转换view为bitmap
  * @param view
  * @return
  */
 public Bitmap convertViewToBitmap(View view){
  view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
  view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
  view.buildDrawingCache();
  Bitmap bitmap = view.getDrawingCache();
  return bitmap;
 }
 private BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
}

调用函数

public void print(String data) {
  View view = LayoutInflater.from(this).inflate(R.layout.print_test,
    null, false);
//这几句可以注释掉，是另一个条形码生成的方法
  /* ImageView bar_img = (ImageView) view
    .findViewById(R.id.print_img_barcode);
  try {
   bar_img.setImageBitmap(testCODE39(data));
  } catch (Exception e) {
  } */
  PrintUtil printer = new PrintUtil();
  printer.shotViewAsImage(btn_print, view, true);
 }