孙广东   2016.7.9

http://blog.csdn.net/u010019717

扫描二维码  需要类库   zxing.unity.dll 

http://zxingnet.codeplex.com/    Unity可以使用！

普通的  Unity 不会用到扫描二维码的功能，   但是在 AR 产品上有应用了！！！！

        参考这个AR产品 ：https://detail.tmall.com/item.htm?spm=a220m.1000858.1000725.1.a7gnRz&id=529056403159&areaId=110100&cat_id=2&rn=22493d7ebf3a196f610ce18fa2504dc0&user_id=2090287044&is_b=1

           购买完内容（AR需要识别的图案卡片 和 激活卡）  要使用通过下载APP扫描（手机，平板都行）  激活卡的二维码， 设备（安装APP的手机或者平板）才能被解锁！

                APP升级不用重新扫描激活卡，说明是激活的设备不是APP.

http://blog.csdn.net/u010019717

using System.Threading;
using UnityEngine.UI;
using UnityEngine;
using System.Collections;
using ZXing;
using ZXing.QrCode;

public class BarcodeCam : MonoBehaviour
{
	public Texture2D encoded;
	public RawImage camsx;       // UI上用于显示摄像头显示的内容
	public Text Rstext;          // ZXing解析的 结果
	//private string TESTstr;    // 网络返回的验证数据结果
	private int sw, sh;
	public static string driverID;   // 设备唯一标识

    // 代表着摄像机
	private WebCamTexture camTexture;
	private Thread qrThread;

	private Color32[] c;
	private int cw, ch;
	private Rect screenRect;
	private bool isQuit;

	public string LastResult;
	private string QRscan;
	private bool shouldEncodeNow;

	void OnGUI()
	{

		GUI.Label(screenRect, driverID);

	}

	void OnEnable()
	{
        // 开启相机
		if (camTexture != null)
		{
			camTexture.Play();
			cw = camTexture.width;
			ch = camTexture.height;
		}
	}

	void OnDisable()
	{
        // 暂停 相机
		if (camTexture != null)
		{
			camTexture.Pause();
		}
	}

	void OnDestroy()
	{
		qrThread.Abort();
		camTexture.Stop();
	}
	void OnApplicationQuit()
	{
		isQuit = true;
	}

	void Start()
	{
        // 设备唯一  ID
		driverID = SystemInfo.deviceUniqueIdentifier;
		encoded = new Texture2D(256, 256);
		LastResult = "www.baidu.com";
		shouldEncodeNow = false;
		screenRect = new Rect(0, 0, Screen.width, Screen.height);
		camTexture = new WebCamTexture();
		if (Screen.width < 1280)
		{
			sw = 640;
		}
		else
		{
			sw = 1280;
		}

        // 在 Unity界面上显示  扫描的内容
		camTexture.requestedHeight = 720;
		camTexture.requestedWidth = sw;
		camsx.texture = camTexture;
		camsx.material.mainTexture = camTexture;
		OnEnable();

		qrThread = new Thread(DecodeQR);
		qrThread.Start();

	}

	void Update()
	{
        // 获取扫描的内容
		if ((c == null) && (camTexture.isPlaying))
		{
			c = camTexture.GetPixels32();
			cw = camTexture.width;
			ch = camTexture.height;
		}

		Rstext.text = LastResult;

		camsx.enabled = false;

		camsx.enabled = true;

		var textForEncoding = LastResult;
		if (shouldEncodeNow &&
			textForEncoding != null)
		{
			var color32 = Encode(textForEncoding, encoded.width, encoded.height);
			encoded.SetPixels32(color32);
			encoded.Apply();
			shouldEncodeNow = false;
			if (QRscan != LastResult)
			{
				QRscan = LastResult;

                // todo 如果遇到新的 二维码那么就执行 其他的操作（网络请求验证啊等等）
				//StartCoroutine(CheckCode(LastResult));
			}
		}
	}

    // 解码 扫描的内容
	void DecodeQR()
	{
		var barcodeReader = new BarcodeReader { AutoRotate = false, TryHarder = false };

		while (true)
		{
			if (isQuit)
				break;

			try
			{

				if (c != null)
				{
					var result = barcodeReader.Decode(c, cw, ch);
					if (result != null)
					{
						LastResult = result.Text;
						shouldEncodeNow = true;
					}

					Thread.Sleep(200);
					c = null;
				}
			}
			catch
			{
			}
		}
	}

	private static Color32[] Encode(string textForEncoding, int width, int height)
	{
		var writer = new BarcodeWriter
		{
			Format = BarcodeFormat.QR_CODE,
			Options = new QrCodeEncodingOptions
			{
				Height = height,
				Width = width
			}
		};
		return writer.Write(textForEncoding);
	}
}