Android中將布局文件轉成bitmap

在實踐中發現，有些需要打印的小票高度小於屏幕的高度，而有些小票內容過多高度高於屏幕高度。

小於屏幕高度的布局文件轉成bitmap較為容易，高於屏幕高度的布局文件轉成長圖bitmap較為復雜。

一.小於屏幕高度的布局文件轉成bitmap

1.需求

在交易過程中常常需要打印小票，利用布局文件組織小票格式，並將其轉成bitmap之后打印出來較為方便。

2.布局文件轉bitmap

public class ReceiptViewActivity extends Activity{
 private View view;
 private boolean isEnd = false;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 LayoutInflater layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
 view = layoutInflater.inflate(R.layout.activity_receiptview, null);
 setContentView(view);

 new Thread(new Runnable() {
 @Override
 public void run() {
 while (!isEnd){
 try {
 view.buildDrawingCache();
 Bitmap bitmap = Bitmap.createBitmap(view.getDrawingCache());
 Pic pic = new Pic(bitmap);
 Printer printer = new Printer(SaleActivity.dal);
 int printstatus = printer.printbitmap(pic);
 if (printstatus == 0){
 isEnd = true;
 }
 }catch (Exception e){
 e.printStackTrace();
 }
 }
 }
 }).start();
 }
}

二.高於屏幕高度的布局文件轉成bitmap

1.需求

有時小票內容過多，屏幕顯示不下，需要滾動顯示並打印完整小票。

2.利用ScrlooView實現滾動顯示

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:layout_gravity="center_horizontal"
 android:background="@color/white"
 android:orientation="vertical"
 android:scrollbars="none"
 android:id="@+id/scrollview">
 <LinearLayout
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:layout_gravity="center_horizontal"
 android:orientation="vertical">
 <TextView
 android:id="@+id/counter"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:layout_marginTop="@dimen/greater_magrin_space"
 android:gravity="center"
 android:text="10s"
 android:textColor="@color/black"
 android:textSize="@dimen/content_text_size_standard"/>
 <TextView
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:layout_marginTop="@dimen/greater_magrin_space"
 android:gravity="center"
 android:text="@string/title_sale"
 android:textColor="@color/black"
 android:textSize="@dimen/content_text_size_standard"/>
 <TextView
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:layout_marginTop="@dimen/content_header_space"
 android:gravity="center"
 android:text="@string/processing"
 android:textColor="@color/black"
 android:textSize="@dimen/content_text_size_standard"/>
 <TextView
 android:layout_width="match_parent"
 android:layout_height="@dimen/greater_magrin_space" />
 <TextView
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:layout_marginTop="@dimen/greater_magrin_space"
 android:gravity="center"
 android:text="10s"
 android:textColor="@color/black"
 android:textSize="@dimen/content_text_size_standard"/>

    </LinearLayout>

</ScrollView>

3.布局文件轉bitmap

public class ReceiptViewActivity extends Activity{
 private ScrollView scrollView;
 private boolean isEnd = false;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_receiptview);

 scrollView = (ScrollView)findViewById(R.id.scrollview);

 new Thread(new Runnable() {
 @Override
 public void run() {
 while (!isEnd){
 try {
 Bitmap bitmap = getBitmapByView(scrollView);
 Pic pic = new Pic(bitmap);
 Printer printer = new Printer(SaleActivity.dal);
 int printstatus = printer.printbitmap(pic);
 if (printstatus == 0){
 isEnd = true;
 }
 }catch (Exception e){
 e.printStackTrace();
 }
 }
 }
 }).start();
 }
　　//ScrollView 轉成bitmap長圖
 public static Bitmap getBitmapByView(ScrollView scrollView) {
 int h = 0;
 Bitmap bitmap = null;

 for (int i = 0; i < scrollView.getChildCount(); i++) {
 h += scrollView.getChildAt(i).getHeight();
 scrollView.getChildAt(i).setBackgroundColor(
 Color.parseColor("#ffffff"));
 }

 bitmap = Bitmap.createBitmap(scrollView.getWidth(), h,
 Bitmap.Config.RGB_565);
 final Canvas canvas = new Canvas(bitmap);
 scrollView.draw(canvas);
 return bitmap;
 }
}