android图片拼接 图形验证码多行多列拼接

做了一个需求，后台接口返回给前端的不是一张完整的图形验证码而是4行5列的base64的数组，接口内容如下

 

{
	"status": "2000",
	"message": "success",
	"data": [
		[{
			"x": 0,
			"y": 0,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAAfUlEQVR42mP4jws8OQLBhAAOdQz/\naQRoYvC/f/9oY/C5HWeob/D3z9/+17tW4zGY2MhDA6tbV/wvNs7DYTDMUGIMR1J3Z8f6/6Wm+TgM\nRjeMkOFQ+c9vP/1v9q4HG9rq24BmMC5D8BkOFP9ybd//GscKsKHV9uX/L+w+/x8Ao/z21VGxpJMA\nAAAASUVORK5CYII="
		}, {
			"x": 0,
			"y": 9,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAA70lEQVR42mP4DwJPjiAwMh8ZoKuB\ngm839/+fndr2v9g473+pWcH/60ev/p+TP/M/w39cAJvhaODpzSf/m93LwYaCcHdg7f/52Z3/S03z\n8RhMBNg8YQPcUHTMkGA75T8Io3gVF0YDiyvngw0ptygEB0OdcyWYX+9ShXAxzAK4RUQEy4bedf9X\nVUz4/+jApv+vHr78v3XKZrDBy+uX4A4KvBZhsfTKwcv/yy2LwS4/vPwAgTBGcilOi4Dyv+8f/N/o\nConEEmDEfbqyh/xUgRw3n6/uhUfaxPhesDxFqQIG/v399//YmiP/t0/bCk6CIAAALx+oXLNtiTQA\nAAAASUVORK5CYII="
		}, {
			"x": 0,
			"y": 18,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAAPklEQVR42mP4TyPAMIwMfnIEgqlq\nMMxQYgxHVwvFDARdSshwHPIMRHkfn+F4DUb3NjbFuIKGKBeTE3k4whgAuTYG+mHrzJgAAAAASUVO\nRK5CYII="
		}, {
			"x": 0,
			"y": 27,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAAMklEQVR42mP4Tyl4cgSC0QADhgJ8\nmCyDyXAVZQbjM5RsgwkZiicIGSgylOIwJgMMPYMBr/0KAGH6ORoAAAAASUVORK5CYII="
		}],
		[{
			"x": 22,
			"y": 0,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAAdElEQVR42mP4DwNPjkAwNoBLDiaO\nRY7hP40Aw9KaRf/P7zxLfYOLjfP+V9uX/5+ROeX/zRM3qGswDM/Mmkobg6emTsSvGl8E4zP41tZ1\n1DO41rECbOj2jhmYmpCTEzEY2eByy+L/LT4N/3/fP4TfNSS4FgQAhjvm7OUB4RgAAAAASUVORK5C\nYII="
		}, {
			"x": 22,
			"y": 9,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAAyUlEQVR42mMoNs77v3nixv+fr+z5\n//fR4f9YwZMjhDGaegaQwTDc5Fb+/92zt7gNxWcpGkAxGITPbD1NmktxGbxr9o7/e+ft+j83o/3/\novzu/3///CXaVXhdTJJmUlxMiavwu5iAzcianz758L+388B/F7vp/030+v7HhC/9P6lp+f+3l/eT\n52JQMpzVufK/ueGE/8a6fSg4zGf6/3dXD+AxGAf49+///6qyrXCDnGyn/S8t3PQ/I3n1f0ebaf9v\nXH+JoefF87f/AaWBxmSRZ+2DAAAAAElFTkSuQmCC"
		}, {
			"x": 22,
			"y": 18,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAABKklEQVR42mP4TwDMnHbsv7FuHxj3\n9xz8/+PHb7zqP338+r+mZOZ/BnyKLpx7+t9Uvx9s6LIl5/4TA+ZM2/g/J7kHv8GJsSvAhtZWbifK\n0BfP34INzU/rw23w2TNP4EHQ2br3f7Dfgv8WhhP+xwTN/L9963Wseu7efgI2eGrfGqDBT478R8FQ\n0NOxH24wyOV7d9/+P70d4gNQ8Ny4/hKr4Tu3nvjfUjsfycVoBkeHLQEbkh4z5/+fh4fBcjuWbIJb\ntnXRhv+4HAUCWA3++/fffyuTSWADDh+8B5fPip8LN/junTd4wxurwe/efYMbcPH8U7D40Q1b4WKp\nUbPxuhbExxrGXz7//G+iBzFk3Zx1/89u3/7f0RLiA1vzyf8fPXz/H1cQgsC/f///AwA/m6Zt46R7\nNwAAAABJRU5ErkJggg=="
		}, {
			"x": 22,
			"y": 27,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAAbElEQVR42mP4DwNPjkAwFIQGLPxv\nrNuHgk31+/7vW7UZoRYZI4Hv337+Z8Bl8NUrL/4X5mz472A19b+N6YT/DhYT/2/ddO0/BsBi8McP\nX3AbjFUzPowGSDOYBDkGQjaTbzAlLiYqKKgMhp7BADi+8PweUYAWAAAAAElFTkSuQmCC"
		}],
		[{
			"x": 44,
			"y": 0,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAAWUlEQVR42mP4/+TIfzAGAWQ2DGAT\nIwIw/KcRGDUYzWBcEUhmxNHYYGwGYcNQcK7LFIxJMxiHi+u/XIJjGDjbafZ/U43L/5kFAf9nTlr0\nf0rPvP/HDp6GywMA5Bv9LwPA5b4AAAAASUVORK5CYII="
		}, {
			"x": 44,
			"y": 9,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAABUElEQVR42pXS3UoCURQFYF+q5+im\nQIxgKsnCcvIPCpUiksqstNCEIMXC9EKjKKEILBgsGFRQMBTEKKFMijDzcla6wdEJMVuwb9ac87EP\njAwlDn1PI6YiB9bvxThjBDPMQm13Yl87CI1CBWZIA/4uRWdlnZf6idXsIIBVmlHIP1K3WEtDGzqk\nfmNajqRt4Bf8x7bNfLx/wqRbRZLPiJ0gCLAtuwg+C19S1x3uTB8vCgfOCVUz8/iq1nrAPTbuTDqV\nhXvLS+jUqBHZTE789u+Nyy8VWPRrmFToCWzNSTAquSbCpec3BFx+WHQ7mFVu4uIo2HXjg71jCdga\n1YgB9e96G67mYvA5fA3MjpkJ6URP4xK4/FqBUq4laKzxq9lX3FhgrSJ+zyXasNngIWROtQ2PM4JI\nKEYbN7ub64TkebErjoD1pV08FUvUxW95Ec4/FMSzP9o/kivKS9FCAAAAAElFTkSuQmCC"
		}, {
			"x": 44,
			"y": 18,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAABQUlEQVR42q2S30vCUBTH7x9ZvQX9\npB7KRBCiJpksSJqhLMok3CgJSUETKXoSUSiix54CQ1gPUWZuEe2H85u7i7FFIf34wIHLOfd+7rmH\nS+YmOayv7uPhvg2L0JYAKxeNHEDXDbjRNB2K/OLJrTFxjA354J9mYJqmkycbbAa6ZgsU5RW+mRiW\nAjt4askYRC5TolIrLmpXnhppPXbsblQdu3wB81MxsLnsQGnx6NSRWuvPEMPo4vKkiFCApyMoCofg\nqsd29a5OQ31TnQNyR8H2pkCFEyN+nJUrX15MWCYNMSFCjIsIL+5BbVSpjMo/xI2bJsRklgpnR4MY\nH15ANMyjeSt9+yJiHexJdUSW0zgvFRyZW0zjh1DxdaWMUDCFbn8sbpEj/wWkJ9XArSRRyee9Hf6l\n6/5ekmBT/Z/A4bmt4D95B9IgxMBQ/O73AAAAAElFTkSuQmCC"
		}, {
			"x": 44,
			"y": 27,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAAQUlEQVR42mPITen531Ez/T8YPDmC\nG5MIGHKSe/4vm7oI1WBkQK7BP+4e/P/19gHquxhFIzVdjNXgwe1iGoGhZzAAmoUBZGfjkcgAAAAA\nSUVORK5CYII="
		}],
		[{
			"x": 66,
			"y": 0,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAA20lEQVR42mP4jw6eHIFgQoCAOob/\nNAIEDf7x6/f/P3/+Usfgf//+/d9w5Nx/38oJ/1Wjyv+rAHFw7ZT/J6/dJd/gRy/f/g+pm/pfObIM\nA2vEVv6/9uAZ6QaDXOpW0Aw3yDa37f+FO4/+P371FkxbZDb/z5+0lAwXA2N50+aVYK8nNvT8//r9\nJ1zq09fv/41S6v9n9y9GTRU4MAO25HPl3pP/fx4dRklO5TNWgX2xaOdRnMnt+Mmb/wtK5/33D+uA\nGowrTULFl+4+DjY0vm02znQ8d+He/16BrXAMACDdzhrX/3TOAAAAAElFTkSuQmCC"
		}, {
			"x": 66,
			"y": 9,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAABkElEQVR42n2S7StDcRTH7/9CIsUr\n/4SHF4wXs0Ye8vBCq6tsy1iIFl4oTW1FnmZyRSElNWMeXihGsZqMMhrD0tZmj1+7x1z3tnHq2+/X\nOb/z+XZOPwbeQ5D4EN8zwa0voUChRq3GgFDk87cgesutnaC8epgkqx9D36AVzNlomQT005BKpTC/\nc4Tixl7U6Y0IhiM53zltm6ioGSEoy07i7cqGd9ceGH3oEjxcLB46s+1AoVKLKu0EHv0BZEUaGr07\nQFOHkaBq3QKi0TiVHryvYISRMgq4bahpa0WevIdO7fMpePNcYIt5kaAtnVMIBn8nchy7wMTiCZg2\n7NCYOCiGTCht7icoryKlBiqVXJiEN/gxCd/uQyY3EPj8wiPxnLPYwXj97wLoL914fdQgXtfOyipB\nu7qns4Zh1bNgEokkSpr6/gW7H3xZzZ0NLIG3rCuSVT45dynPkIPRKgHl16uFUzlszoJGIjFUyr6/\n14v/Q1LTDVjR3mX6BueKZPpn/BWe+2eC1irGJXnH0TXll7lDfAGjQ2/0tFbQvAAAAABJRU5ErkJg\ngg=="
		}, {
			"x": 66,
			"y": 18,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAApElEQVR42mP4Twa4fPXhf6/A1v/R\niRP+f/z4FSx2686z/6HRPf8z82b9//nz938Gcgy+c/c52OCEtCn/G9tW/W/rWvvfL6T9f3zq5P9P\nn70DqyHLYBCYNH3bf/+wDjBOzJj6fzKQ//7DF7g8psFPjkAwEeDv33845RiwGkqM4ehq0TADTpcS\nMpyAPANeRfg0EzQYWQGQznsVi9vLJLuYnMgjEMYAJlDrQZ/QXoYAAAAASUVORK5CYII="
		}, {
			"x": 66,
			"y": 27,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAANElEQVR42mP4Ty54cgSCcQAGuAJ8\nmCyDyXUV2QYT0EiewYQMRVaDAzOQZSjFYUwBGHoGAwBlKAlU8Ri0CwAAAABJRU5ErkJggg=="
		}],
		[{
			"x": 88,
			"y": 0,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAARUlEQVR42mP4/+TIfzDGBnDJwcTx\nyDH8pxEYNZhEg/FFMA71DERpIsfgosLJ/x+f3YU7ORGDsSU3r8DW/6UlU6jqWhAGANboA922paYt\nAAAAAElFTkSuQmCC"
		}, {
			"x": 88,
			"y": 9,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAAXklEQVR42mPwCmz9n5LW9x8reHKE\nMMahniEqrvt/TdU0/IbisxSHOIN3UNv/DUtWkO5SQgaDguLTzf2kuYoYF+flTySsmRwXb1q6knRX\nEePiW8e308ZgSjTjN5hGAACBYe14UZsGqgAAAABJRU5ErkJggg=="
		}, {
			"x": 88,
			"y": 18,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAAR0lEQVR42mP4TyPAQDODZ+1o/I+O\naeZibJaR5IAnR4AGAwkwxgdwqMFpIU6DYWLEYix6CbuYGB+RbDCZrsVvMC7NhHwCFQcAa5jrc7sd\nN6kAAAAASUVORK5CYII="
		}, {
			"x": 88,
			"y": 27,
			"img": "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABYAAAAJCAYAAAA2NNx1AAAAL0lEQVR42mP4/+TIfzBGBjAxYjA6\ngIoz4FSAbAEpciQZPPRcTDeDiQoKGoGhZzAAxEcAmH7LnCgAAAAASUVORK5CYII="
		}]
	]
}

尝试了几种方法，记录一下，也给没做过类似需求的人一个参考

将上述代码以json文件保存，放到项目assert目录下

读取json文件并解析数据

private void getDataFromJson() {
        StringBuilder newstringBuilder = new StringBuilder();
        InputStream inputStream = null;
        try {
            inputStream = getResources().getAssets().open("bitmap.json");
            InputStreamReader isr = new InputStreamReader(inputStream);
            BufferedReader reader = new BufferedReader(isr);
            String jsonLine;
            while ((jsonLine = reader.readLine()) != null) {
                newstringBuilder.append(jsonLine);
            }
            reader.close();
            isr.close();
            inputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

        String result = newstringBuilder.toString();
        Gson gson = new Gson();
        ImageCodeEntity codeEntity = gson.fromJson(result, ImageCodeEntity.class);
        imageCode = codeEntity.getData();

    }

然后根据imagecode数据拼接图片，方法一就是死办法，一个一个拼

private void setData() {
        List imageCodeEntitie0 = imageCode.get(0);
        List imageCodeEntitie1 = imageCode.get(1);
        List imageCodeEntitie2 = imageCode.get(2);
        List imageCodeEntitie3 = imageCode.get(3);
        List imageCodeEntitie4 = imageCode.get(4);

        Bitmap viewColume0 = PjbTextUtils.fromUpToDown(PjbTextUtils.stringToBitmap(imageCodeEntitie0.get(0).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie0.get(1).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie0.get(2).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie0.get(3).getImg()));
        Bitmap viewColume1 = PjbTextUtils.fromUpToDown(PjbTextUtils.stringToBitmap(imageCodeEntitie1.get(0).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie1.get(1).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie1.get(2).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie1.get(3).getImg()));
        Bitmap viewColume2 = PjbTextUtils.fromUpToDown(PjbTextUtils.stringToBitmap(imageCodeEntitie2.get(0).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie2.get(1).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie2.get(2).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie2.get(3).getImg()));
        Bitmap viewColume3 = PjbTextUtils.fromUpToDown(PjbTextUtils.stringToBitmap(imageCodeEntitie3.get(0).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie3.get(1).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie3.get(2).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie3.get(3).getImg()));
        Bitmap viewColume4 = PjbTextUtils.fromUpToDown(PjbTextUtils.stringToBitmap(imageCodeEntitie4.get(0).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie4.get(1).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie4.get(2).getImg())
                , PjbTextUtils.stringToBitmap(imageCodeEntitie4.get(3).getImg()));

        bitmapFinal = PjbTextUtils.fromLeftToRight(viewColume0, viewColume1, viewColume2, viewColume3, viewColume4);
        ivImagecode1.setImageBitmap(bitmapFinal);
    }

这样明显代码量太多，而且繁杂，改进成方法二，代码如下

 private void setData2() {
        List bitmapColume = new ArrayList<>();
        List bitmapRow = new ArrayList<>();
        for (int r = 0; r < imageCode.size(); r++) {
            List imageCodeEntitie = imageCode.get(r);
            for (int c = 0; c < imageCodeEntitie.size(); c++) {
                bitmapColume.add(c, PjbTextUtils.stringToBitmap2(imageCodeEntitie.get(c).getImg()));
            }
            bitmapRow.add(PjbTextUtils.fromUpToDown(bitmapColume.get(0), bitmapColume.get(1), bitmapColume.get(2), bitmapColume.get(3)));
        }

        bitmapFinal = PjbTextUtils.fromLeftToRight(bitmapRow.get(0), bitmapRow.get(1), bitmapRow.get(2), bitmapRow.get(3), bitmapRow.get(4));
        ivImagecode.setImageBitmap(bitmapFinal);
    }

但是思考后感觉还是不够灵活，如果后台改了数据格式就会报错，因此诞生方法三

   private Bitmap getBitmap(List> data) {
        Bitmap result = Bitmap.createBitmap(200, 100, Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(result);
        int width = 0;
        int height = 0;
        for (List datum : data) {
            for (DataBean dataBean : datum) {
                Bitmap b = PjbTextUtils.stringToBitmap(dataBean.getImg());
                width = Math.max(dataBean.getX() + b.getWidth(), width);
                height = Math.max(dataBean.getY() + b.getHeight(), height);
                canvas.save();
                canvas.clipRect(0, 0, width, height);
                canvas.drawBitmap(b, dataBean.getX(), dataBean.getY(), null);
                canvas.restore();
            }
        }
        result = Bitmap.createBitmap(result, 0, 0, width, height);
        return result;
    }

上面用到的工具类方法如下

  /**
     * 从上往下拼接图片
     *
     * @param bit1
     * @param bit2
     * @param bit3
     * @param bit4
     * @return
     */
    public static Bitmap fromUpToDown(Bitmap bit1, Bitmap bit2, Bitmap bit3, Bitmap bit4) {
        int width = bit1.getWidth();
        int height = bit1.getHeight() + bit2.getHeight() + bit3.getHeight() + bit4.getHeight();
        //创建一个空的Bitmap(内存区域),宽度等于第一张图片的宽度，高度等于两张图片高度总和
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_4444);
        //将bitmap放置到绘制区域,并将要拼接的图片绘制到指定内存区域
        Canvas canvas = new Canvas(bitmap);
        canvas.drawBitmap(bit1, 0, 0, null);
        canvas.drawBitmap(bit2, 0, bit1.getHeight(), null);
        canvas.drawBitmap(bit3, 0, bit1.getHeight() + bit2.getHeight(), null);
        canvas.drawBitmap(bit4, 0, bit1.getHeight() + bit2.getHeight() + bit3.getHeight(), null);
        return bitmap;
    }

    public static Bitmap fromUpToDown2(Bitmap bit1, Bitmap bit2) {
        int width = bit1.getWidth();
        int height = bit1.getHeight() + bit2.getHeight();
        //创建一个空的Bitmap(内存区域),宽度等于第一张图片的宽度，高度等于两张图片高度总和
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_4444);
        //将bitmap放置到绘制区域,并将要拼接的图片绘制到指定内存区域
        Canvas canvas = new Canvas(bitmap);
        canvas.drawBitmap(bit1, 0, 0, null);
        canvas.drawBitmap(bit2, 0, bit1.getHeight(), null);
        return bitmap;
    }

    /**
     * 从左往右拼接图片
     *
     * @param bit1
     * @param bit2
     * @param bit3
     * @param bit4
     * @param bit5
     * @return
     */
    public static Bitmap fromLeftToRight(Bitmap bit1, Bitmap bit2, Bitmap bit3, Bitmap bit4, Bitmap bit5) {

        int width = bit1.getWidth() + bit2.getWidth() + bit3.getWidth() + bit4.getWidth();
        int height = bit1.getHeight();
        //创建一个空的Bitmap(内存区域),宽度等于第一张图片的宽度，高度等于两张图片高度总和
        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_4444);
        //将bitmap放置到绘制区域,并将要拼接的图片绘制到指定内存区域
        Canvas canvas = new Canvas(bitmap);
        canvas.drawBitmap(bit1, 0, 0, null);
        canvas.drawBitmap(bit2, bit1.getWidth(), 0, null);
        canvas.drawBitmap(bit3, bit1.getWidth() + bit2.getWidth(), 0, null);
        canvas.drawBitmap(bit4, bit1.getWidth() + bit2.getWidth() + bit3.getWidth(), 0, null);
        canvas.drawBitmap(bit5, bit1.getWidth() + bit2.getWidth() + bit3.getWidth() + bit5.getWidth(), 0, null);
        return bitmap;
    }

    /**
     * base64转bitmap
     *
     * @param string
     * @return
     */
    public static Bitmap stringToBitmap(String string) {
        Bitmap bitmap = null;
        try {
            byte[] bitmapArray = Base64.decode(string.split(",")[1], Base64.DEFAULT);
            bitmap = BitmapFactory.decodeByteArray(bitmapArray, 0, bitmapArray.length);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return bitmap;
    }

    /**
     * base64转bitmap
     *
     * @param string
     * @return
     */
    public static Bitmap stringToBitmap2(String string) {
        Bitmap bitmap = null;
        try {
            byte[] bitmapArray = Base64.decode(string.replace("data:image/png;base64,", ""), Base64.DEFAULT);
            bitmap = BitmapFactory.decodeByteArray(bitmapArray, 0, bitmapArray.length);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return bitmap;
    }

最终效果图如下