二維碼的掃描和生成(zxing-android-embedded)的基礎使用
阿新 • • 發佈：2018-11-15
簡述:這個部落格主要記載zxing-android-embedded的簡單使用，如何替換相機的佈局，如何去掉生成二維碼的空白等等一系列問題.
zxing-android-embedded的使用
1.首先新增依賴
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.journeyapps:zxing-android-embedded:3.6.0'
2.生成二維碼
private void createQrCode(){
BarcodeEncoder barcodeEncoder = new BarcodeEncoder();
try {
BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, 400, 400);
bitMatrix =deleteWhite(bitMatrix); //刪除二維碼周邊的空白處
qrCodeBitmap=barcodeEncoder.createBitmap(bitMatrix);
qrCodeImg.setImageBitmap(qrCodeBitmap);
} catch (WriterException e) {
e.printStackTrace();
}
}3.掃描二維碼
/**
* 掃描二維碼
*/
private void scanQrCode(){
IntentIntegrator intentIntegrator = new IntentIntegrator(this);
intentIntegrator.setDesiredBarcodeFormats(IntentIntegrator.QR_CODE); //設定掃描的型別
intentIntegrator.setOrientationLocked(false); //方向鎖定
intentIntegrator.setCaptureActivity(CustomCaptureActivity.class);
intentIntegrator.setCameraId(0); //前置相機還是後置相機
intentIntegrator.setBeepEnabled(false); //是否發出成功的聲音
intentIntegrator.setBarcodeImageEnabled(true);
intentIntegrator.initiateScan();
}
方向鎖定的話，你還需要設定CaptureActivity，假如你是按依賴新增的而不是匯入原始碼，那麼需要
public class CustomCaptureActivity extends CaptureActivity {
}
在AndroidManifest裡面設定
<activity android:name=".custom.CustomCaptureActivity" android:screenOrientation="fullSensor" tools:replace="screenOrientation"/>
在掃描完成之後，他會自動返回到onActivityResult()函式裡面
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
IntentResult result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data);
if(result != null) {
if(result.getContents() == null) {
Toast.makeText(this, "Cancelled", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(this, "Scanned: " + result.getContents(), Toast.LENGTH_LONG).show();
}
} else {
super.onActivityResult(requestCode, resultCode, data);
}
}
這裡的result.getContents()就是二維碼內含的值
刪除二維碼生成時候的周圍的空白
zing-android-embedde原始生成的二維碼周圍會有很多的空白,所以自己需要刪除空白
/**
* 刪除二維碼的空白區域
* @param matrix
* @return
*/
private static BitMatrix deleteWhite(BitMatrix matrix)
{
int[] rec = matrix.getEnclosingRectangle();
//數字7 代表了留的空白區域的大小
int resWidth = rec[2] + 10;
int resHeight = rec[3] + 10;
BitMatrix resMatrix = new BitMatrix(resWidth, resHeight);
resMatrix.clear();
for (int i = 10; i < resWidth; i++)
{
for (int j = 10; j < resHeight; j++)
{
if(matrix.get(i+rec[0],j+rec[1]))
resMatrix.set(i,j);
}
}
return resMatrix;
}
自定義二維碼掃描時候掃描的大小
因為zxing-android-embedded生成的介面比較難看，所以一般需要修改原生的介面。一般是修改原始碼或者是繼承
本文因為是採用依賴導成jar進來的，所以採用的是繼承的方式。
public class CustomCaptureActivity extends CaptureActivity {
private ImageView oldBackImg;
private CustomDecoratedBarcodeView customDecoratedBarcodeView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
oldBackImg = findViewById(R.id.oldBackImg);
oldBackImg.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
finish();
}
});
}
@Override
protected DecoratedBarcodeView initializeContent(){
setContentView(R.layout.custom_activity_zxing_capture);
customDecoratedBarcodeView= findViewById(R.id.zxing_custom_barcode_scanner);
return customDecoratedBarcodeView;
}
}
最主要的是inittializeContent()方法，這個方法可以設定除了掃描以外的介面，比如加一個標題欄等等
DecoratedBarcodeView 就是掃描最重要的組成部分，他由兩個View組成，第一個BarcodeView就是掃描的視窗，
第二個Viewfinder有效果。 所以我們如果想繪製掃描的介面可以重寫Viewfineder的onDraw()方法
package backup.wingos.com.wingbackup.custom;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.Log;
import com.journeyapps.barcodescanner.ViewfinderView;
import backup.wingos.com.wingbackup.R;
/**
* Created by xiongbo on 2018/11/14.
*/
public class CustomViewfinderView extends ViewfinderView {
private static final String TAG = "CustomViewfinderView";
/**
* 畫相機四個角落的值
*/
private Paint customPaint;
/**
* 獲取相機的區域
*/
private Rect frame;
/**
* 修改這個值 可以修改角落繪製的顏色
*/
private int color;
/**
* 四個角落的寬度
*/
private int cornerWidth;
/**
* 四個角落的厚度
*/
private int cornerHeight;
/**
* 你需要在相機下面顯示的文字
*/
private String text;
/**
* 中間橫線豎直的位置
*/
private int direction;
/**
* 代表了第一次繪製
*/
private boolean isFirst;
/**
* 是否獲取二維碼的結果
*/
private boolean isResult;
/**
* 是否退出執行緒
*/
private boolean isExit;
private Thread thread;
public CustomViewfinderView(Context context, AttributeSet attrs) {
super(context, attrs);
customPaint = new Paint();
customPaint.setStyle(Paint.Style.FILL);
color=getResources().getColor(R.color.colorPrimary);
customPaint.setAntiAlias(true);
cornerWidth=50;
cornerHeight=8;
text="Scan the QR code from new phone";
isFirst = true;
isResult=false;
isExit=false;
thread = new Thread(new Runnable() {
@Override
public void run() {
while(!isExit){
setDirection(direction+2);
try {
thread.sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
thread.start();
}
@Override
public void onDraw(Canvas canvas) {
super.refreshSizes();
if (framingRect == null || previewFramingRect == null) {
return;
}
frame = framingRect;
if(isFirst){
isFirst=false;
direction=frame.top+10;
}
customPaint.setColor(color);
customPaint.setStrokeWidth((float) 1.5);
/**
* 繪製四條邊框
*/
canvas.drawLine(frame.left,frame.top,frame.right,frame.top,customPaint);
canvas.drawLine(frame.left,frame.top,frame.left,frame.bottom,customPaint);
canvas.drawLine(frame.right,frame.top,frame.right,frame.bottom,customPaint);
canvas.drawLine(frame.right,frame.bottom,frame.left,frame.bottom,customPaint);
final int width = canvas.getWidth();
final int height = canvas.getHeight();
// Draw the exterior (i.e. outside the framing rect) darkened
paint.setColor(resultBitmap != null ? resultColor : maskColor);
canvas.drawRect(0, 0, width, frame.top, paint);
canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint);
canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1, paint);
canvas.drawRect(0, frame.bottom + 1, width, height, paint);
if (resultBitmap != null) {
// Draw the opaque result bitmap over the scanning rectangle
paint.setAlpha(CURRENT_POINT_OPACITY);
canvas.drawBitmap(resultBitmap, null, frame, paint);
isResult=true;
} else {
customPaint.setAlpha(100);
Rect rect = new Rect(frame.left,frame.top,frame.right, direction);
canvas.drawRect(rect,customPaint);
customPaint.setAlpha(255);
customPaint.setStrokeWidth(3);
canvas.drawLine(frame.left,direction,frame.right,direction,customPaint);
if(direction>=frame.bottom){
direction=frame.top;
}
}
if(isResult){
isExit=true;
}else{
isExit=false;
}
drawCorner(1,canvas);
drawCorner(2,canvas);
drawCorner(3,canvas);
drawCorner(4,canvas);
drawText(text,canvas);
}
public void setColor(int color){
this.color=color;
invalidate();
}
/**
* 繪製四個角落 type: 1--左上 2--右上 3--左下 4--右下
*/
private void drawCorner(int type,Canvas canvas){
Rect verticalRect=null;
Rect horizontalRect =null;
if(type==1){
horizontalRect = new Rect(frame.left,frame.top,frame.left+cornerWidth,frame.top+cornerHeight);
verticalRect = new Rect(frame.left,frame.top,frame.left+cornerHeight,frame.top+cornerWidth);
}else if(type==2){
horizontalRect = new Rect(frame.right-cornerWidth,frame.top,frame.right,frame.top+cornerHeight);
verticalRect = new Rect(frame.right-cornerHeight,frame.top,frame.right,frame.top+cornerWidth);
}else if(type==3){
horizontalRect = new Rect(frame.left,frame.bottom-cornerWidth,frame.left+cornerHeight,frame.bottom);
verticalRect = new Rect(frame.left,frame.bottom-cornerHeight,frame.left+cornerWidth,frame.bottom);
}else{
horizontalRect = new Rect(frame.right-cornerWidth,frame.bottom-cornerHeight,frame.right,frame.bottom);
verticalRect = new Rect(frame.right-cornerHeight,frame.bottom-cornerWidth,frame.right,frame.bottom);
}
canvas.drawRect(horizontalRect,customPaint);
canvas.drawRect(verticalRect,customPaint);
}
public void setText(String text){
this.text=text;
}
private void drawText(String text,Canvas canvas){
customPaint.setColor(getResources().getColor(R.color.colorWhite));
customPaint.setTextSize(50);
canvas.drawText(text,frame.left-30,frame.bottom+100,customPaint);
}
private void setDirection(int direction){
this.direction=direction;
invalidate();
}
public void stopThread(){
isExit=true;
if(thread!=null){
thread=null;
}
}
}
首先我們的framingRect 代表了視窗區域，我們繪製的時候不能繪製在視窗的區域裡面，要不然會攔住視窗，因為Viewfinder是繪製在BarcodeView的上方的.修改視窗的大小，其實是有屬性的，他們自定義View的style如下
<?xml version="1.0" encoding="UTF-8"?> <resources> <declare-styleable name="zxing_view"> <attr name="zxing_scanner_layout" format="reference"/> </declare-styleable> <declare-styleable name="zxing_camera_preview"> <attr name="zxing_framing_rect_width" format="dimension" /> //視窗大小 <attr name="zxing_framing_rect_height" format="dimension" /> <attr name="zxing_use_texture_view" format="boolean" /> <attr name="zxing_preview_scaling_strategy" format="enum"> <enum name="centerCrop" value="1" /> <enum name="fitCenter" value="2" /> <enum name="fitXY" value="3" /> </attr> </declare-styleable> <declare-styleable name="zxing_finder"> <attr name="zxing_possible_result_points" format="color"/> <attr name="zxing_result_view" format="color"/> <attr name="zxing_viewfinder_laser" format="color"/> <attr name="zxing_viewfinder_mask" format="color"/> //繪製背景的顏色 </declare-styleable> </resources>
我們自定義的話，可以把這個style複製到自己專案裡面。也可以直接用；只要在BarcodeView設定屬性就好了
<backup.wingos.com.wingbackup.custom.CustomBarcodeView android:id="@+id/zxing_custom_barcode_surface" android:layout_width="match_parent" android:layout_height="match_parent" app:zxing_framing_rect_height="240dp" app:zxing_framing_rect_width="240dp" /> <backup.wingos.com.wingbackup.custom.CustomViewfinderView android:id="@+id/zxing_custom_viewfinder_view" android:layout_width="match_parent" android:layout_height="match_parent" app:zxing_viewfinder_mask="#757575" />
這樣就完成效果了。而且原生的話，關閉會有一定的延時效果，所以我們可以把這個延時關閉掉，影響使用者體驗
/**
* 造成了延時效果
* 本來為 2000000000 修改成了 10000000
*/
@Override
public void pauseAndWait() {
CameraInstance instance = getCameraInstance();
pause();
long startTime = System.nanoTime();
while(instance != null && !instance.isCameraClosed()) {
if(System.nanoTime() - startTime > 10000000) {
// Don't wait for longer than 2 seconds
break;
}
try {
Thread.sleep(1);
} catch (InterruptedException e) {
break;
}
}
}
這需要在CustomBarcodeView裡面修改的，因為原生的BarcodeView在退出的時候會阻塞主執行緒2s鍾。