android生成二维码

	private EditText et1;
	private Button btn1;
	private ImageView iv1;
	
	private static final int IMAGE_HALFWIDTH = 35;//图片宽度值大小

                et1 = (EditText)findViewById(R.id.editText1);
		btn1 = (Button)findViewById(R.id.button1);
		iv1 = (ImageView)findViewById(R.id.imageView1);

		btn1.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				String toMakePic_string = et1.getText().toString().trim();
				Bitmap logo= BitmapFactory.decodeResource(getResources(),R.drawable._netcfg);
				
				try {
					Bitmap bm=createCode(toMakePic_string,logo,BarcodeFormat.QR_CODE); //一个方法在下面
					iv1.setImageBitmap(bm);
				} catch (WriterException e) {
					e.printStackTrace();
				}
			}
		});

    public Bitmap createCode(String string,Bitmap mBitmap, BarcodeFormat format)throws WriterException {
    	//Matrix，中文里叫矩阵，在图像处理方面，主要是用于平面的缩放、平移、旋转等操作。
    	Matrix m = new Matrix();
    	float sx = (float) 2 * IMAGE_HALFWIDTH / mBitmap.getWidth();
		float sy = (float) 2 * IMAGE_HALFWIDTH / mBitmap.getHeight();
		m.setScale(sx, sy);//设置缩放信息
		//将logo图片按martix设置的信息缩放
		mBitmap = Bitmap.createBitmap(mBitmap, 0, 0,mBitmap.getWidth(), mBitmap.getHeight(), m, false);
		MultiFormatWriter writer = new MultiFormatWriter();
		Hashtable hst = new Hashtable();
		hst.put(EncodeHintType.CHARACTER_SET, "UTF-8");//设置字符编码
		//生成二维码矩阵信息
		BitMatrix matrix = writer.encode(string, format, 800, 800, hst);
		int width = matrix.getWidth();//矩阵高度
		int height = matrix.getHeight();//矩阵宽度
		int halfW = width / 2;
		int halfH = height / 2;
		int[] pixels = new int[width * height];//定义数组长度为矩阵高度*矩阵宽度，用于记录矩阵中像素信息
		for (int y = 0; y < height; y++) {//从行开始迭代矩阵
			for (int x = 0; x < width; x++) {//迭代列
				if (x > halfW - IMAGE_HALFWIDTH && x < halfW + IMAGE_HALFWIDTH && y > halfH - IMAGE_HALFWIDTH && y < halfH + IMAGE_HALFWIDTH) {
					//该位置用于存放图片信息
					//记录图片每个像素信息
					pixels[y * width + x] = mBitmap.getPixel(x - halfW+ IMAGE_HALFWIDTH, y - halfH + IMAGE_HALFWIDTH); 
				}
				else {
					if (matrix.get(x, y)) {
						//如果有黑块点，记录信息
						pixels[y * width + x] = 0xff000000;//记录黑块信息
					}
				}
			}
		}
		Bitmap bitmap = Bitmap.createBitmap(width, height,Bitmap.Config.ARGB_8888);
		// 通过像素数组生成bitmap
		bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
		return bitmap;
	}