Litchi 2016-08-02
最近用到了二维码的生成功能,用的是googlezxing工具,结果生成的二维码老是有一个边框,没办法去掉。查了一下zxing的源码,发现边框是自动计算出来的,不能手动设置。差评~~
这个方法:
private static BitMatrix renderResult(QRCode code, int width, int height, int quietZone)
package com.google.zxing.qrcode; import com.google.zxing.BarcodeFormat; import com.google.zxing.EncodeHintType; import com.google.zxing.Writer; import com.google.zxing.WriterException; import com.google.zxing.common.BitMatrix; import com.google.zxing.qrcode.encoder.ByteMatrix; import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel; import com.google.zxing.qrcode.encoder.Encoder; import com.google.zxing.qrcode.encoder.QRCode; import java.util.Map; /** * This object renders a QR Code as a BitMatrix 2D array of greyscale values. * * @author [email protected] (Daniel Switkin) */ public final class QRCodeWriter implements Writer { private static final int QUIET_ZONE_SIZE = 4; @Override public BitMatrix encode(String contents, BarcodeFormat format, int width, int height) throws WriterException { return encode(contents, format, width, height, null); } @Override public BitMatrix encode(String contents, BarcodeFormat format, int width, int height, Map<EncodeHintType,?> hints) throws WriterException { if (contents.length() == 0) { throw new IllegalArgumentException("Found empty contents"); } if (format != BarcodeFormat.QR_CODE) { throw new IllegalArgumentException("Can only encode QR_CODE, but got " + format); } if (width < 0 || height < 0) { throw new IllegalArgumentException("Requested dimensions are too small: " + width + 'x' + height); } ErrorCorrectionLevel errorCorrectionLevel = ErrorCorrectionLevel.L; int quietZone = QUIET_ZONE_SIZE; if (hints != null) { ErrorCorrectionLevel requestedECLevel = (ErrorCorrectionLevel) hints.get(EncodeHintType.ERROR_CORRECTION); if (requestedECLevel != null) { errorCorrectionLevel = requestedECLevel; } Integer quietZoneInt = (Integer) hints.get(EncodeHintType.MARGIN); if (quietZoneInt != null) { quietZone = quietZoneInt; } } QRCode code = Encoder.encode(contents, errorCorrectionLevel, hints); return renderResult(code, width, height, quietZone); } // Note that the input matrix uses 0 == white, 1 == black, while the output matrix uses // 0 == black, 255 == white (i.e. an 8 bit greyscale bitmap). private static BitMatrix renderResult(QRCode code, int width, int height, int quietZone) { ByteMatrix input = code.getMatrix(); if (input == null) { throw new IllegalStateException(); } int inputWidth = input.getWidth(); int inputHeight = input.getHeight(); int qrWidth = inputWidth + (quietZone << 1); int qrHeight = inputHeight + (quietZone << 1); int outputWidth = Math.max(width, qrWidth); int outputHeight = Math.max(height, qrHeight); int multiple = Math.min(outputWidth / qrWidth, outputHeight / qrHeight); // Padding includes both the quiet zone and the extra white pixels to accommodate the requested // dimensions. For example, if input is 25x25 the QR will be 33x33 including the quiet zone. // If the requested size is 200x160, the multiple will be 4, for a QR of 132x132. These will // handle all the padding from 100x100 (the actual QR) up to 200x160. int leftPadding = (outputWidth - (inputWidth * multiple)) / 2; int topPadding = (outputHeight - (inputHeight * multiple)) / 2; BitMatrix output = new BitMatrix(outputWidth, outputHeight); for (int inputY = 0, outputY = topPadding; inputY < inputHeight; inputY++, outputY += multiple) { // Write the contents of this row of the barcode for (int inputX = 0, outputX = leftPadding; inputX < inputWidth; inputX++, outputX += multiple) { if (input.get(inputX, inputY) == 1) { output.setRegion(outputX, outputY, multiple, multiple); } } } return output; } }