生成文字的二维码

//此代码需要关于二维码的jar包

<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"
    tools:context="com.example.zxing.MainActivity" >
    <EditText
        android:id="@+id/editText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginTop="23dp"
        android:ems="10" >
        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/button1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:text="生成一个二维码" />
    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_below="@+id/editText1"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="89dp"
        android:src="@drawable/ic_launcher"/>
</RelativeLayout>

package com.example.zxing;
import com.google.zxing.WriterException;
import android.app.Activity;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;

public class MainActivity extends Activity{
    //定义控件
    private EditText mEditText;
    private Button button;
    private ImageView image;
    protected int mScreenWidth ;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获得控件的id 
        mEditText=(EditText) findViewById(R.id.editText1);
        button=(Button) findViewById(R.id.button1);
        image=(ImageView) findViewById(R.id.imageView1);
        DisplayMetrics dm = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(dm);
        mScreenWidth = dm.widthPixels;
        button.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                String string = mEditText.getText().toString();

                    Bitmap bitmap;
                    try {
                        bitmap = BitmapUtil.createQRCode(string, mScreenWidth);
                        if(bitmap != null){
                            image.setImageBitmap(bitmap);
                        }
                    } catch (WriterException e) {
                        e.printStackTrace();
                    }

            }
        });
    }
}

package com.example.zxing;

import java.util.Hashtable;
import android.graphics.Bitmap;
import android.util.Log;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;

public class BitmapUtil{
    /**
     * 生成一个二维码图像
     * 
     * @param url
     *            传入的字符串，通常是一个URL
     * @param QR_WIDTH
     *            宽度（像素值px）
     * @param QR_HEIGHT
     *            高度（像素值px）
     * @return
     */
    public static final Bitmap create2DCoderBitmap(String url, int QR_WIDTH,
            int QR_HEIGHT) {
        try {
            // 判断URL合法性
            if (url == null || "".equals(url) || url.length() < 1) {
                return null;
            }
            Hashtable<EncodeHintType, String> hints = new Hashtable<EncodeHintType, String>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
            // 图像数据转换，使用了矩阵转换
            BitMatrix bitMatrix = new QRCodeWriter().encode(url,
                    BarcodeFormat.QR_CODE, QR_WIDTH, QR_HEIGHT, hints);
            int[] pixels = new int[QR_WIDTH * QR_HEIGHT];
            // 下面这里按照二维码的算法，逐个生成二维码的图片，
            // 两个for循环是图片横列扫描的结果
            for (int y = 0; y < QR_HEIGHT; y++){
                for (int x = 0; x < QR_WIDTH; x++){
                    if (bitMatrix.get(x, y)) {
                        pixels[y * QR_WIDTH + x] = 0xff000000;
                    } else {
                        pixels[y * QR_WIDTH + x] = 0xffffffff;
                    }
                }
            }
            // 生成二维码图片的格式，使用ARGB_8888
            Bitmap bitmap = Bitmap.createBitmap(QR_WIDTH, QR_HEIGHT,
                    Bitmap.Config.ARGB_8888);
            bitmap.setPixels(pixels, 0, QR_WIDTH, 0, 0, QR_WIDTH, QR_HEIGHT);
            // 显示到一个ImageView上面
            // sweepIV.setImageBitmap(bitmap);
            return bitmap;
        } catch (WriterException e) {
            Log.i("log", "生成二维码错误" + e.getMessage());
            return null;
        }
    }

    private static final int BLACK = 0xff000000;

    /**
     * 生成一个二维码图像
     * 
     * @param url
     *            传入的字符串，通常是一个URL
     * @param widthAndHeight
     *           图像的宽高
     * @return
     */
    public static Bitmap createQRCode(String str, int widthAndHeight)
            throws WriterException {
        Hashtable<EncodeHintType, String> hints = new Hashtable<EncodeHintType, String>();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        BitMatrix matrix = new MultiFormatWriter().encode(str,
                BarcodeFormat.QR_CODE, widthAndHeight, widthAndHeight);
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        int[] pixels = new int[width * height];

        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                if (matrix.get(x, y)) {
                    pixels[y * width + x] = BLACK;
                }
            }
        }
        Bitmap bitmap = Bitmap.createBitmap(width, height,
                Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
        return bitmap;
    }
}