如何在两个activity之间传递bitmap

1、需求

在项目开发过程中，打印小票前需要添加打印预览功能，交易数据在打印前转成bitmap然后直接打印，为了显示这个bitmap需要将其传给显示activity。

2、解决方法

把bitmap存储为byte数组，然后再通过Intent传递。

3、XML布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <include layout="@layout/header_layout" />

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="455dp"
            android:layout_weight="1">
            <ImageView
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_marginTop="25dp"
                android:layout_marginLeft="18dp"
                android:layout_marginRight="17.5dp"
                android:src="@drawable/print_preview"/>

            <ImageView
                android:id="@+id/printPreview"
                android:layout_width="match_parent"
                android:layout_height="385dp"
                android:layout_marginTop="60dp"
                android:layout_marginLeft="61.5dp"
                android:layout_marginRight="61dp"/>
        </RelativeLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="0"
            android:orientation="horizontal">
            <Button
                android:id="@+id/cancel_button"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:background="@drawable/selection_button_gray_left"
                android:text="Cancel"
                android:textColor="@color/cancel_button_text"/>
            <Button
                android:id="@+id/print_button"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:background="@drawable/selection_button_blue_right"
                android:text="Print"
                android:textColor="@color/key_normal_color"/>
        </LinearLayout>
    </LinearLayout>

</LinearLayout>

4、生成bitmap

public class ReceiptPreviewTrans {

    public Bitmap preview(TransData transData){
        ReceiptGeneratorTrans receiptGeneratorTrans = new ReceiptGeneratorTrans(transData, 1, 1, false);
        return receiptGeneratorTrans.generate();
    }
}

5、ActionPrintPreview实现

public class ActionPrintPreview extends AAction {

    private Context context;
    private Handler handler;
    private TransData transData;

    public ActionPrintPreview(ActionStartListener listener) {
        super(listener);
    }

    public void setParam(Context context, Handler handler, TransData transData) {
        this.context = context;
        this.handler = handler;
        this.transData = transData;
    }

    @Override
    protected void process() {
        ReceiptPreviewTrans receiptPreviewTrans = new ReceiptPreviewTrans();
        Bitmap bitmap = receiptPreviewTrans.preview(transData);
        Intent intent = new Intent(context, PrintPreviewActivity.class);
        ByteArrayOutputStream baos=new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
        byte [] bitmapByte =baos.toByteArray();
        intent.putExtra("bitmap", bitmapByte);
        context.startActivity(intent);
    }
}

6、PrintPreviewActivity实现

public class PrintPreviewActivity extends BaseActivityWithTickForAction implements View.OnClickListener{

    private TextView headerText;
    private ImageView backBtn;

    private Bitmap bitmap;
    private byte [] bis;
    private ImageView imageView;
    private Button btnCancel;
    private Button btnPrint;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Device.enableStatusBar(false);
    }

    @Override
    protected void onResume() {
        super.onResume();
    }

    @Override
    protected void loadParam() {
        Intent intent=getIntent();
        if(intent !=null)
        {
            bis=intent.getByteArrayExtra("bitmap");
            bitmap= BitmapFactory.decodeByteArray(bis, 0, bis.length);
        }
    }

    @Override
    protected int getLayoutId() {
        return R.layout.activity_print_preview_layout;
    }

    @Override
    protected void initViews() {
        headerText = (TextView) findViewById(R.id.header_title);
        headerText.setText(R.string.preview);
        backBtn = (ImageView) findViewById(R.id.header_back);
        backBtn.setVisibility(View.GONE);

        imageView = (ImageView)findViewById(R.id.printPreview);
        imageView.setImageBitmap(bitmap);
        btnCancel = (Button)findViewById(R.id.cancel_button);
        btnPrint = (Button)findViewById(R.id.print_button);
    }

    @Override
    protected void setListeners(){
        btnCancel.setOnClickListener(this);
        btnPrint.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {

        switch (v.getId()) {
            case R.id.cancel_button:
                break;
            case R.id.print_button:
                finish(new ActionResult(TransResult.SUCC, null));
                break;
            default:
                break;
        }

    }

    @Override
    protected void handleMsg(Message msg) {

    }

    public void finish(ActionResult result) {
        tickTimerStop();
        AAction action = TransContext.getInstance().getCurrentAction();
        if (action != null) {
            action.setResult(new ActionResult(TransResult.SUCC, result.getData()));
        } else {
            finish();
        }
    }
}

7、效果图