自定义生成二维码，可添加logo

在敲代码之前要记得导入jar包 core-3.2.1.jar 复制百度搜索就可以下载得到

package com.gss.zxingdemo;

import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.xys.libzxing.zxing.activity.CaptureActivity;

import java.util.HashMap;
import java.util.Map;

public class MainActivity extends AppCompatActivity {

private ImageView erweima;
private ImageView img;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
erweima = (ImageView) findViewById(R.id.erweima);
img = (ImageView) findViewById(R.id.diyerweima);
//点击按钮吧ip地址生成二维码
findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Bitmap bitmap = generateBitmap("http://blog.csdn.net/u012702547/article/details/51501350", 400, 400);
Bitmap bitmap2 = addBackground(bitmap, BitmapFactory.decodeResource(getResources(), R.drawable.background));

erweima.setImageBitmap(bitmap2);
}
});

//点击生成带logo的二维码
findViewById(R.id.button2).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Bitmap bitmap = generateBitmap("孙明亮不是傻逼，孙明亮是臭傻逼", 600, 600);
Bitmap logo = BitmapFactory.decodeResource(getResources(), R.drawable.jjjj);
Bitmap bitmap1 = addLogo(bitmap, logo);
img.setImageBitmap(bitmap1);
}
});

}
/**
* 生成二维码
*/
private Bitmap generateBitmap(String content, int width, int height) {
QRCodeWriter qrCodeWriter = new QRCodeWriter();
Map<EncodeHintType, String> hints = new HashMap<>();
hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
try {
BitMatrix encode = qrCodeWriter.encode(content, BarcodeFormat.QR_CODE, width, height, hints);
int[] pixels = new int[width * height];
for (int i = 0; i < height; i++) {
for (int j = 0; j < width; j++) {
if (encode.get(j, i)) {
pixels[i * width + j] = 0x00000000;
} else {
pixels[i * width + j] = 0xffffffff;
}
}
}
return Bitmap.createBitmap(pixels, 0, width, width, height, Bitmap.Config.RGB_565);

} catch (Exception e) {
e.printStackTrace();
}
return null;
}

/**
* 给二维码图片加背景
*/
public static Bitmap addBackground(Bitmap foreground, Bitmap background) {
int bgWidth = background.getWidth();
int bgHeight = background.getHeight();
int fgWidth = foreground.getWidth();
int fgHeight = foreground.getHeight();
Bitmap newmap = Bitmap
.createBitmap(bgWidth, bgHeight, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(newmap);
canvas.drawBitmap(background, 0, 0, null);
canvas.drawBitmap(foreground, (bgWidth - fgWidth) / 2,
(bgHeight - fgHeight) * 3 / 5 + 70, null);
canvas.save(Canvas.ALL_SAVE_FLAG);
canvas.restore();
return newmap;
}

/**
* 添加图标
*
* @param qrBitmap
* @param logoBitmap
* @return
*/
private Bitmap addLogo(Bitmap qrBitmap, Bitmap logoBitmap) {
int qrBitmapWidth = qrBitmap.getWidth();
int qrBitmapHeight = qrBitmap.getHeight();
int logoBitmapWidth = logoBitmap.getWidth();
int logoBitmapHeight = logoBitmap.getHeight();
Bitmap blankBitmap = Bitmap.createBitmap(qrBitmapWidth, qrBitmapHeight, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(blankBitmap);
canvas.drawBitmap(qrBitmap, 0, 0, null);
canvas.save(Canvas.ALL_SAVE_FLAG);
float scaleSize = 1.0f;
while ((logoBitmapWidth / scaleSize) > (qrBitmapWidth / 5) || (logoBitmapHeight / scaleSize) > (qrBitmapHeight / 5)) {
scaleSize *= 2;
}
float sx = 1.0f / scaleSize;
canvas.scale(sx, sx, qrBitmapWidth / 2, qrBitmapHeight / 2);
canvas.drawBitmap(logoBitmap, (qrBitmapWidth - logoBitmapWidth) / 2, (qrBitmapHeight - logoBitmapHeight) / 2, null);
canvas.restore();
return blankBitmap;
}
}