Android 基於google Zxing實現二維碼、條形碼掃描，仿微信二維碼掃描效果

轉載請註明出處：http://blog.csdn.net/xiaanming/article/details/10163203

瞭解二維碼這個東西還是從微信中，當時微信推出二維碼掃描功能，自己感覺挺新穎的，從一張圖片中掃一下竟然能直接加好友，不可思議啊，那時候還不瞭解二維碼，呵呵，然後做項目的時候，老闆說要加上二維碼掃描功能，然後自己的屁顛屁顛的去百度，google啥的，發現很多朋友都有介紹二維碼掃描的功能，然後我就跟着人家的介紹自己搞起了二維碼掃描功能，跟着人家的帖子，很快我的項目就加入了掃描二維碼的功能，然後自己還很開心。

隨着微信的到來，二維碼越來越火爆，隨處能看到二維碼，比如商城裏面，肯德基，餐廳等等，對於二維碼掃描我們使用的是google的開源框架Zxing,我們可以去http://code.google.com/p/zxing/下載源碼和Jar包，之前我項目中的二維碼掃描功能只實現了掃描功能，其UI真的是其醜無比，一個好的應用軟件，其UI界面也要被大衆所接納，不然人家就不會用你的軟件啦，所以說應用軟件功能和界面一樣都很重要，例如微信，相信微信UI被很多應用軟件所模仿，我也仿照微信掃描二維碼效果進行模仿，雖然沒有微信做的那麼精緻，但是效果還是可以的，所以將自己修改UI的代碼和掃描二維碼的代碼分享給大家，一是自己以後項目遇到同樣的功能直接拷貝來用，二是給還沒有加入二維碼功能的人一個參考，站在巨人的肩膀上,哈哈，我之前也是站在巨人的肩膀上加上此功能，接下來跟着我一步一步來實現此項功能，裏面去除了很多不必要的文件

我們先看下項目的結構

如果你項目也想加入此功能，你直接將com.mining.app.zxing.camera，com.mining.app.zxing.decoding，com.mining.app.zxing.view這三個包拷貝到你的項目中，然後引入相對應的資源進去，我也是從我的項目中直接引用過來的，包名都沒改呢，當然還需要引用Zxing.jar

com.example.qr_codescan包裏面有一個MipcaActivityCapture,也是直接引入我之前項目的代碼的，這個Activity主要處理掃描界面的類，比如，掃描成功有聲音和振動等等，主要關注裏面的handleDecode(Result result, Bitmap barcode)方法，掃描完成之後將掃描到的結果和二維碼的bitmap當初參數傳遞到handleDecode(Result result, Bitmap barcode)裏面，我們只需要在裏面寫出相對應的處理代碼即可，其他的地方都不用改得，我這裏處理掃描結果和掃描拍的照片

[java] view plain copy print ?

/**
* 處理掃描結果
* @param result
* @param barcode
*/
public void handleDecode(Result result, Bitmap barcode) {
inactivityTimer.onActivity();
playBeepSoundAndVibrate();
String resultString = result.getText();
if (resultString.equals("")) {
Toast.makeText(MipcaActivityCapture.this, "Scan failed!", Toast.LENGTH_SHORT).show();
}else {
Intent resultIntent = new Intent();
Bundle bundle = new Bundle();
bundle.putString("result", resultString);
bundle.putParcelable("bitmap", barcode);
resultIntent.putExtras(bundle);
this.setResult(RESULT_OK, resultIntent);
}
MipcaActivityCapture.this.finish();
}

	/**
	 * 處理掃描結果
	 * @param result
	 * @param barcode
	 */
	public void handleDecode(Result result, Bitmap barcode) {
		inactivityTimer.onActivity();
		playBeepSoundAndVibrate();
		String resultString = result.getText();
		if (resultString.equals("")) {
			Toast.makeText(MipcaActivityCapture.this, "Scan failed!", Toast.LENGTH_SHORT).show();
		}else {
			Intent resultIntent = new Intent();
			Bundle bundle = new Bundle();
			bundle.putString("result", resultString);
			bundle.putParcelable("bitmap", barcode);
			resultIntent.putExtras(bundle);
			this.setResult(RESULT_OK, resultIntent);
		}
		MipcaActivityCapture.this.finish();
	}

我對MipcaActivityCapture界面的佈局做了自己的改動，先看下效果圖，主要是用到FrameLayout,裏面嵌套RelativeLayout，裏面的圖片也是從微信裏面拿出來的，平常我看到需要什麼圖片就去微信裏面找，沒有美工的公司的程序員就是苦逼

佈局代碼如下

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<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<SurfaceView
android:id="@+id/preview_view"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_gravity="center" />
<com.mining.app.zxing.view.ViewfinderView
android:id="@+id/viewfinder_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<include
android:id="@+id/include1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
layout="@layout/activity_title" />
</RelativeLayout>
</FrameLayout>

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

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >

        <SurfaceView
            android:id="@+id/preview_view"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:layout_gravity="center" />

        <com.mining.app.zxing.view.ViewfinderView
            android:id="@+id/viewfinder_view"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

        <include
            android:id="@+id/include1"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            layout="@layout/activity_title" />
    </RelativeLayout>

</FrameLayout>

在裏面我將界面上面部分寫在另一個佈局裏面，然後include進來，因爲這個activity_title在我項目裏面還供其他的Activity使用，我也是直接拷貝出來的

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<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="@drawable/mmtitle_bg_alpha" >
<Button
android:id="@+id/button_back"
android:layout_width="75.0dip"
android:text="返回"
android:background="@drawable/mm_title_back_btn"
android:textColor="@android:color/white"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginLeft="2dip" />
<TextView
android:id="@+id/textview_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="@+id/button_back"
android:layout_alignBottom="@+id/button_back"
android:layout_centerHorizontal="true"
android:gravity="center_vertical"
android:text="二維碼掃描"
android:textColor="@android:color/white"
android:textSize="18sp" />
</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/mmtitle_bg_alpha" >

    <Button
        android:id="@+id/button_back"
        android:layout_width="75.0dip"
        android:text="返回"
        android:background="@drawable/mm_title_back_btn"
        android:textColor="@android:color/white"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_marginLeft="2dip" />

    <TextView
        android:id="@+id/textview_title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/button_back"
        android:layout_alignBottom="@+id/button_back"
        android:layout_centerHorizontal="true"
        android:gravity="center_vertical"
        android:text="二維碼掃描"
        android:textColor="@android:color/white"
        android:textSize="18sp" />

</RelativeLayout>

在我這個demo裏面，有一個主界面MainActivity，裏面一個Button，一個ImageView和一個TextView,點擊Button進入到二維碼掃描界面，當掃描OK的時候，回到主界面，將掃描的結果顯示到TextView，將圖片顯示到ImageView裏面，然後你可以不處理圖片，我這裏隨帶的加上圖片，主界面的佈局很簡單如下

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<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#ffe1e0de" >
<Button
android:id="@+id/button1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:text="掃描二維碼" />
<TextView
android:id="@+id/result"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/button1"
android:lines="2"
android:gravity="center_horizontal"
android:textColor="@android:color/black"
android:textSize="16sp" />
<ImageView
android:id="@+id/qrcode_bitmap"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_alignParentLeft="true"
android:layout_below="@+id/result"/>
</RelativeLayout>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ffe1e0de" >

    <Button
        android:id="@+id/button1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:text="掃描二維碼" />

    <TextView
        android:id="@+id/result"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/button1"
        android:lines="2"
        android:gravity="center_horizontal"
        android:textColor="@android:color/black"
        android:textSize="16sp" />

    <ImageView
        android:id="@+id/qrcode_bitmap"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/result"/>
</RelativeLayout>

MainActivity裏面的代碼如下，裏面的功能在上面已經說了

[java] view plain copy print ?

package com.example.qr_codescan;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
public class MainActivity extends Activity {
private final static int SCANNIN_GREQUEST_CODE = 1;
/**
* 顯示掃描結果
*/
private TextView mTextView ;
/**
* 顯示掃描拍的圖片
*/
private ImageView mImageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextView = (TextView) findViewById(R.id.result);
mImageView = (ImageView) findViewById(R.id.qrcode_bitmap);
//點擊按鈕跳轉到二維碼掃描界面，這裏用的是startActivityForResult跳轉
//掃描完了之後調到該界面
Button mButton = (Button) findViewById(R.id.button1);
mButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent();
intent.setClass(MainActivity.this, MipcaActivityCapture.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivityForResult(intent, SCANNIN_GREQUEST_CODE);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch (requestCode) {
case SCANNIN_GREQUEST_CODE:
if(resultCode == RESULT_OK){
Bundle bundle = data.getExtras();
//顯示掃描到的內容
mTextView.setText(bundle.getString("result"));
//顯示
mImageView.setImageBitmap((Bitmap) data.getParcelableExtra("bitmap"));
}
break;
}
}
}

package com.example.qr_codescan;


import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

public class MainActivity extends Activity {
	private final static int SCANNIN_GREQUEST_CODE = 1;
	/**
	 * 顯示掃描結果
	 */
	private TextView mTextView ;
	/**
	 * 顯示掃描拍的圖片
	 */
	private ImageView mImageView;
	

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		mTextView = (TextView) findViewById(R.id.result); 
		mImageView = (ImageView) findViewById(R.id.qrcode_bitmap);
		
		//點擊按鈕跳轉到二維碼掃描界面，這裏用的是startActivityForResult跳轉
		//掃描完了之後調到該界面
		Button mButton = (Button) findViewById(R.id.button1);
		mButton.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				Intent intent = new Intent();
				intent.setClass(MainActivity.this, MipcaActivityCapture.class);
				intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
				startActivityForResult(intent, SCANNIN_GREQUEST_CODE);
			}
		});
	}
	
	
	@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode) {
		case SCANNIN_GREQUEST_CODE:
			if(resultCode == RESULT_OK){
				Bundle bundle = data.getExtras();
				//顯示掃描到的內容
				mTextView.setText(bundle.getString("result"));
				//顯示
				mImageView.setImageBitmap((Bitmap) data.getParcelableExtra("bitmap"));
			}
			break;
		}
    }	

}

上面的代碼還是比較簡單，但是要想做出像微信那樣只的掃描框，緊緊上面的代碼是沒有那種效果的，我們必須重寫com.mining.app.zxing.view包下面的ViewfinderView類，微信裏面的都是用的圖片，我是自己畫出來的，代碼註釋的比較清楚，大家直接看代碼吧，相信你能理解的，如果你要修改掃描框的大小，去CameraManager類裏面修改

[java] view plain copy print ?

/*
* Copyright (C) 2008 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.mining.app.zxing.view;
import java.util.Collection;
import java.util.HashSet;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.view.View;
import com.example.qr_codescan.R;
import com.google.zxing.ResultPoint;
import com.mining.app.zxing.camera.CameraManager;
/**
* This view is overlaid on top of the camera preview. It adds the viewfinder
* rectangle and partial transparency outside it, as well as the laser scanner
* animation and result points.
*
*/
public final class ViewfinderView extends View {
private static final String TAG = "log";
/**
* 刷新界面的時間
*/
private static final long ANIMATION_DELAY = 10L;
private static final int OPAQUE = 0xFF;
/**
* 四個綠色邊角對應的長度
*/
private int ScreenRate;
/**
* 四個綠色邊角對應的寬度
*/
private static final int CORNER_WIDTH = 10;
/**
* 掃描框中的中間線的寬度
*/
private static final int MIDDLE_LINE_WIDTH = 6;
/**
* 掃描框中的中間線的與掃描框左右的間隙
*/
private static final int MIDDLE_LINE_PADDING = 5;
/**
* 中間那條線每次刷新移動的距離
*/
private static final int SPEEN_DISTANCE = 5;
/**
* 手機的屏幕密度
*/
private static float density;
/**
* 字體大小
*/
private static final int TEXT_SIZE = 16;
/**
* 字體距離掃描框下面的距離
*/
private static final int TEXT_PADDING_TOP = 30;
/**
* 畫筆對象的引用
*/
private Paint paint;
/**
* 中間滑動線的最頂端位置
*/
private int slideTop;
/**
* 中間滑動線的最底端位置
*/
private int slideBottom;
private Bitmap resultBitmap;
private final int maskColor;
private final int resultColor;
private final int resultPointColor;
private Collection<ResultPoint> possibleResultPoints;
private Collection<ResultPoint> lastPossibleResultPoints;
boolean isFirst;
public ViewfinderView(Context context, AttributeSet attrs) {
super(context, attrs);
density = context.getResources().getDisplayMetrics().density;
//將像素轉換成dp
ScreenRate = (int)(20 * density);
paint = new Paint();
Resources resources = getResources();
maskColor = resources.getColor(R.color.viewfinder_mask);
resultColor = resources.getColor(R.color.result_view);
resultPointColor = resources.getColor(R.color.possible_result_points);
possibleResultPoints = new HashSet<ResultPoint>(5);
}
@Override
public void onDraw(Canvas canvas) {
//中間的掃描框，你要修改掃描框的大小，去CameraManager裏面修改
Rect frame = CameraManager.get().getFramingRect();
if (frame == null) {
return;
}
//初始化中間線滑動的最上邊和最下邊
if(!isFirst){
isFirst = true;
slideTop = frame.top;
slideBottom = frame.bottom;
}
//獲取屏幕的寬和高
int width = canvas.getWidth();
int height = canvas.getHeight();
paint.setColor(resultBitmap != null ? resultColor : maskColor);
//畫出掃描框外面的陰影部分，共四個部分，掃描框的上面到屏幕上面，掃描框的下面到屏幕下面
//掃描框的左邊面到屏幕左邊，掃描框的右邊到屏幕右邊
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(OPAQUE);
canvas.drawBitmap(resultBitmap, frame.left, frame.top, paint);
} else {
//畫掃描框邊上的角，總共8個部分
paint.setColor(Color.GREEN);
canvas.drawRect(frame.left, frame.top, frame.left + ScreenRate,
frame.top + CORNER_WIDTH, paint);
canvas.drawRect(frame.left, frame.top, frame.left + CORNER_WIDTH, frame.top
+ ScreenRate, paint);
canvas.drawRect(frame.right - ScreenRate, frame.top, frame.right,
frame.top + CORNER_WIDTH, paint);
canvas.drawRect(frame.right - CORNER_WIDTH, frame.top, frame.right, frame.top
+ ScreenRate, paint);
canvas.drawRect(frame.left, frame.bottom - CORNER_WIDTH, frame.left
+ ScreenRate, frame.bottom, paint);
canvas.drawRect(frame.left, frame.bottom - ScreenRate,
frame.left + CORNER_WIDTH, frame.bottom, paint);
canvas.drawRect(frame.right - ScreenRate, frame.bottom - CORNER_WIDTH,
frame.right, frame.bottom, paint);
canvas.drawRect(frame.right - CORNER_WIDTH, frame.bottom - ScreenRate,
frame.right, frame.bottom, paint);
//繪製中間的線,每次刷新界面，中間的線往下移動SPEEN_DISTANCE
slideTop += SPEEN_DISTANCE;
if(slideTop >= frame.bottom){
slideTop = frame.top;
}
canvas.drawRect(frame.left + MIDDLE_LINE_PADDING, slideTop - MIDDLE_LINE_WIDTH/2, frame.right - MIDDLE_LINE_PADDING,slideTop + MIDDLE_LINE_WIDTH/2, paint);
//畫掃描框下面的字
paint.setColor(Color.WHITE);
paint.setTextSize(TEXT_SIZE * density);
paint.setAlpha(0x40);
paint.setTypeface(Typeface.create("System", Typeface.BOLD));
canvas.drawText(getResources().getString(R.string.scan_text), frame.left, (float) (frame.bottom + (float)TEXT_PADDING_TOP *density), paint);
Collection<ResultPoint> currentPossible = possibleResultPoints;
Collection<ResultPoint> currentLast = lastPossibleResultPoints;
if (currentPossible.isEmpty()) {
lastPossibleResultPoints = null;
} else {
possibleResultPoints = new HashSet<ResultPoint>(5);
lastPossibleResultPoints = currentPossible;
paint.setAlpha(OPAQUE);
paint.setColor(resultPointColor);
for (ResultPoint point : currentPossible) {
canvas.drawCircle(frame.left + point.getX(), frame.top
+ point.getY(), 6.0f, paint);
}
}
if (currentLast != null) {
paint.setAlpha(OPAQUE / 2);
paint.setColor(resultPointColor);
for (ResultPoint point : currentLast) {
canvas.drawCircle(frame.left + point.getX(), frame.top
+ point.getY(), 3.0f, paint);
}
}
//只刷新掃描框的內容，其他地方不刷新
postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top,
frame.right, frame.bottom);
}
}
public void drawViewfinder() {
resultBitmap = null;
invalidate();
}
/**
* Draw a bitmap with the result points highlighted instead of the live
* scanning display.
*
* @param barcode
* An image of the decoded barcode.
*/
public void drawResultBitmap(Bitmap barcode) {
resultBitmap = barcode;
invalidate();
}
public void addPossibleResultPoint(ResultPoint point) {
possibleResultPoints.add(point);
}
}

/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.mining.app.zxing.view;

import java.util.Collection;
import java.util.HashSet;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.view.View;

import com.example.qr_codescan.R;
import com.google.zxing.ResultPoint;
import com.mining.app.zxing.camera.CameraManager;

/**
 * This view is overlaid on top of the camera preview. It adds the viewfinder
 * rectangle and partial transparency outside it, as well as the laser scanner
 * animation and result points.
 * 
 */
public final class ViewfinderView extends View {
	private static final String TAG = "log";
	/**
	 * 刷新界面的時間
	 */
	private static final long ANIMATION_DELAY = 10L;
	private static final int OPAQUE = 0xFF;

	/**
	 * 四個綠色邊角對應的長度
	 */
	private int ScreenRate;
	
	/**
	 * 四個綠色邊角對應的寬度
	 */
	private static final int CORNER_WIDTH = 10;
	/**
	 * 掃描框中的中間線的寬度
	 */
	private static final int MIDDLE_LINE_WIDTH = 6;
	
	/**
	 * 掃描框中的中間線的與掃描框左右的間隙
	 */
	private static final int MIDDLE_LINE_PADDING = 5;
	
	/**
	 * 中間那條線每次刷新移動的距離
	 */
	private static final int SPEEN_DISTANCE = 5;
	
	/**
	 * 手機的屏幕密度
	 */
	private static float density;
	/**
	 * 字體大小
	 */
	private static final int TEXT_SIZE = 16;
	/**
	 * 字體距離掃描框下面的距離
	 */
	private static final int TEXT_PADDING_TOP = 30;
	
	/**
	 * 畫筆對象的引用
	 */
	private Paint paint;
	
	/**
	 * 中間滑動線的最頂端位置
	 */
	private int slideTop;
	
	/**
	 * 中間滑動線的最底端位置
	 */
	private int slideBottom;
	
	private Bitmap resultBitmap;
	private final int maskColor;
	private final int resultColor;
	
	private final int resultPointColor;
	private Collection<ResultPoint> possibleResultPoints;
	private Collection<ResultPoint> lastPossibleResultPoints;

	boolean isFirst;
	
	public ViewfinderView(Context context, AttributeSet attrs) {
		super(context, attrs);
		
		density = context.getResources().getDisplayMetrics().density;
		//將像素轉換成dp
		ScreenRate = (int)(20 * density);

		paint = new Paint();
		Resources resources = getResources();
		maskColor = resources.getColor(R.color.viewfinder_mask);
		resultColor = resources.getColor(R.color.result_view);

		resultPointColor = resources.getColor(R.color.possible_result_points);
		possibleResultPoints = new HashSet<ResultPoint>(5);
	}

	@Override
	public void onDraw(Canvas canvas) {
		//中間的掃描框，你要修改掃描框的大小，去CameraManager裏面修改
		Rect frame = CameraManager.get().getFramingRect();
		if (frame == null) {
			return;
		}
		
		//初始化中間線滑動的最上邊和最下邊
		if(!isFirst){
			isFirst = true;
			slideTop = frame.top;
			slideBottom = frame.bottom;
		}
		
		//獲取屏幕的寬和高
		int width = canvas.getWidth();
		int height = canvas.getHeight();

		paint.setColor(resultBitmap != null ? resultColor : maskColor);
		
		//畫出掃描框外面的陰影部分，共四個部分，掃描框的上面到屏幕上面，掃描框的下面到屏幕下面
		//掃描框的左邊面到屏幕左邊，掃描框的右邊到屏幕右邊
		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(OPAQUE);
			canvas.drawBitmap(resultBitmap, frame.left, frame.top, paint);
		} else {

			//畫掃描框邊上的角，總共8個部分
			paint.setColor(Color.GREEN);
			canvas.drawRect(frame.left, frame.top, frame.left + ScreenRate,
					frame.top + CORNER_WIDTH, paint);
			canvas.drawRect(frame.left, frame.top, frame.left + CORNER_WIDTH, frame.top
					+ ScreenRate, paint);
			canvas.drawRect(frame.right - ScreenRate, frame.top, frame.right,
					frame.top + CORNER_WIDTH, paint);
			canvas.drawRect(frame.right - CORNER_WIDTH, frame.top, frame.right, frame.top
					+ ScreenRate, paint);
			canvas.drawRect(frame.left, frame.bottom - CORNER_WIDTH, frame.left
					+ ScreenRate, frame.bottom, paint);
			canvas.drawRect(frame.left, frame.bottom - ScreenRate,
					frame.left + CORNER_WIDTH, frame.bottom, paint);
			canvas.drawRect(frame.right - ScreenRate, frame.bottom - CORNER_WIDTH,
					frame.right, frame.bottom, paint);
			canvas.drawRect(frame.right - CORNER_WIDTH, frame.bottom - ScreenRate,
					frame.right, frame.bottom, paint);

			
			//繪製中間的線,每次刷新界面，中間的線往下移動SPEEN_DISTANCE
			slideTop += SPEEN_DISTANCE;
			if(slideTop >= frame.bottom){
				slideTop = frame.top;
			}
			canvas.drawRect(frame.left + MIDDLE_LINE_PADDING, slideTop - MIDDLE_LINE_WIDTH/2, frame.right - MIDDLE_LINE_PADDING,slideTop + MIDDLE_LINE_WIDTH/2, paint);
			
			
			//畫掃描框下面的字
			paint.setColor(Color.WHITE);
			paint.setTextSize(TEXT_SIZE * density);
			paint.setAlpha(0x40);
			paint.setTypeface(Typeface.create("System", Typeface.BOLD));
			canvas.drawText(getResources().getString(R.string.scan_text), frame.left, (float) (frame.bottom + (float)TEXT_PADDING_TOP *density), paint);
			
			

			Collection<ResultPoint> currentPossible = possibleResultPoints;
			Collection<ResultPoint> currentLast = lastPossibleResultPoints;
			if (currentPossible.isEmpty()) {
				lastPossibleResultPoints = null;
			} else {
				possibleResultPoints = new HashSet<ResultPoint>(5);
				lastPossibleResultPoints = currentPossible;
				paint.setAlpha(OPAQUE);
				paint.setColor(resultPointColor);
				for (ResultPoint point : currentPossible) {
					canvas.drawCircle(frame.left + point.getX(), frame.top
							+ point.getY(), 6.0f, paint);
				}
			}
			if (currentLast != null) {
				paint.setAlpha(OPAQUE / 2);
				paint.setColor(resultPointColor);
				for (ResultPoint point : currentLast) {
					canvas.drawCircle(frame.left + point.getX(), frame.top
							+ point.getY(), 3.0f, paint);
				}
			}

			
			//只刷新掃描框的內容，其他地方不刷新
			postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top,
					frame.right, frame.bottom);
			
		}
	}

	public void drawViewfinder() {
		resultBitmap = null;
		invalidate();
	}

	/**
	 * Draw a bitmap with the result points highlighted instead of the live
	 * scanning display.
	 * 
	 * @param barcode
	 *            An image of the decoded barcode.
	 */
	public void drawResultBitmap(Bitmap barcode) {
		resultBitmap = barcode;
		invalidate();
	}

	public void addPossibleResultPoint(ResultPoint point) {
		possibleResultPoints.add(point);
	}

}

上面的代碼中，中間那根線微信是用的圖片，我這裏是畫的，如果你想更加仿真點就將下面的代碼

[java] view plain copy print ?

canvas.drawRect(frame.left + MIDDLE_LINE_PADDING, slideTop - MIDDLE_LINE_WIDTH/2, frame.right - MIDDLE_LINE_PADDING,slideTop + MIDDLE_LINE_WIDTH/2, paint);

canvas.drawRect(frame.left + MIDDLE_LINE_PADDING, slideTop - MIDDLE_LINE_WIDTH/2, frame.right - MIDDLE_LINE_PADDING,slideTop + MIDDLE_LINE_WIDTH/2, paint);

改成

[java] view plain copy print ?

Rect lineRect = new Rect();
lineRect.left = frame.left;
lineRect.right = frame.right;
lineRect.top = slideTop;
lineRect.bottom = slideTop + 18;
canvas.drawBitmap(((BitmapDrawable)(getResources().getDrawable(R.drawable.qrcode_scan_line))).getBitmap(), null, lineRect, paint);

Rect lineRect = new Rect();
			lineRect.left = frame.left;
			lineRect.right = frame.right;
			lineRect.top = slideTop;
			lineRect.bottom = slideTop + 18;
			canvas.drawBitmap(((BitmapDrawable)(getResources().getDrawable(R.drawable.qrcode_scan_line))).getBitmap(), null, lineRect, paint);

那條掃描線自己去微信裏面找一下，我貼出來的失真了，下載微信apk,將後綴名改成zip,然後解壓就行了

畫掃描框下面字體的代碼需要修改下，這樣子能根據字體自動排列在中間，如果字太長我沒有處理，那個要自動換行，你可以自行處理

[java] view plain copy print ?

paint.setColor(Color.WHITE);
paint.setTextSize(TEXT_SIZE * density);
paint.setAlpha(0x40);
paint.setTypeface(Typeface.DEFAULT_BOLD);
String text = getResources().getString(R.string.R.string.scan_text);
float textWidth = paint.measureText(text);
canvas.drawText(text, (width - textWidth)/2, (float) (frame.bottom + (float)TEXT_PADDING_TOP *density), paint)

paint.setColor(Color.WHITE);  
paint.setTextSize(TEXT_SIZE * density);  
paint.setAlpha(0x40);  
paint.setTypeface(Typeface.DEFAULT_BOLD); 
String text = getResources().getString(R.string.R.string.scan_text);
float textWidth = paint.measureText(text);

canvas.drawText(text, (width - textWidth)/2, (float) (frame.bottom + (float)TEXT_PADDING_TOP *density), paint)

運行界面截圖，其中中間的那根綠色的線會上下移動，跟微信的效果差不多，當然運行你還需要相對應的權限問題，有興趣的朋友可以去下載demo

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