嗨,大家好我已经坚持了一段时间了,我真的很想知道它是如何工作的,以及我没有得到什么.我有一个Apex3,我已经能够毫无问题地跟随
the documentation的大部分,但是当谈到图像时,事情变得非常奇怪(缺乏示例缺乏一致性如何做到这一点).
首先,我尝试尝试使用JPEG和0质量传递Bitmap byte []数组压缩的天真方法,因为我不介意,使用命令
ESC V n1 n2数据
这没有奏效.
然后我发现有一个用于apex3的android库,它接受一个位图并用来打印它,但它不起作用只是打印像这样的怪异符号：
我尝试使用JD gui对jar源进行解码,他们似乎使用位图字节做了一些工作,这是他们的代码(一条建议代码,如addToDoc(m_Document,ESC“B”);只需将代码放入ByteArrayOutputStream数据中),(反编译source from here)：
public void writeImage(Bitmap imageObject, int printHeadWidth)
throws IllegalArgumentException
{
if (imageObject == null) {
throw new IllegalArgumentException("Parameter 'imageObject' was null.");
}
if (printHeadWidth < 1) {
throw new IllegalArgumentException("Parameter 'printHeadWidth' must be greater than 0.");
}
int height = imageObject.getHeight();
int width = imageObject.getWidth();
byte blanklineCount = 0;
byte[] dataline = new byte[printHeadWidth + 7 >> 3];
int[] imageData = new int[height * width];
imageObject.getPixels(imageData, 0, width, 0, 0, width, height);
addToDoc(m_Document, ESC + "B");
for (int row = 0; row < height; row++)
{
boolean blankLine = true;
for (int index = 0; index < width; index += 8)
{
byte currentByte = 0;
int offset = row * width + index;
if (index >= printHeadWidth) {
break;
}
int value = index + 0 < width ? imageData[(offset + 0)] & 0xFFFFFF : 16777215;
boolean set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
currentByte = (byte)(currentByte | (set ? -128 : 0));
value = index + 1 < width ? imageData[(offset + 1)] & 0xFFFFFF : 16777215;
set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
currentByte = (byte)(currentByte | (set ? 64 : 0));
value = index + 2 < width ? imageData[(offset + 2)] & 0xFFFFFF : 16777215;
set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
currentByte = (byte)(currentByte | (set ? 32 : 0));
value = index + 3 < width ? imageData[(offset + 3)] & 0xFFFFFF : 16777215;
set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
currentByte = (byte)(currentByte | (set ? 16 : 0));
value = index + 4 < width ? imageData[(offset + 4)] & 0xFFFFFF : 16777215;
set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
currentByte = (byte)(currentByte | (set ? 8 : 0));
value = index + 5 < width ? imageData[(offset + 5)] & 0xFFFFFF : 16777215;
set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
currentByte = (byte)(currentByte | (set ? 4 : 0));
value = index + 6 < width ? imageData[(offset + 6)] & 0xFFFFFF : 16777215;
set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
currentByte = (byte)(currentByte | (set ? 2 : 0));
value = index + 7 < width ? imageData[(offset + 7)] & 0xFFFFFF : 16777215;
set = (value >> 0 & 0xFF) + (value >> 8 & 0xFF) + (value >> 16 & 0xFF) < 384;
currentByte = (byte)(currentByte | (set ? 1 : 0));
dataline[(index >> 3)] = currentByte;
blankLine &= currentByte == 0;
}
if (!blankLine)
{
if (blanklineCount > 0)
{
addToDoc(m_Document, "A");
addToDoc(m_Document, blanklineCount);
blanklineCount = 0;
}
addToDoc(m_Document, compressGraphicLine(dataline));
}
else
{
blanklineCount = (byte)(blanklineCount + 1);
if (blanklineCount == 255)
{
addToDoc(m_Document, "A");
addToDoc(m_Document, blanklineCount);
blanklineCount = 0;
}
}
}
if (blanklineCount > 0)
{
addToDoc(m_Document, "A");
addToDoc(m_Document, blanklineCount);
blanklineCount = 0;
}
addToDoc(m_Document, ESC + "E");
}
private byte[] compressGraphicLine(byte[] dataline)
{
byte count = 0;
byte currentByte = 0;
ByteArrayOutputStream rleString = new ByteArrayOutputStream(128);
addToDoc(rleString, "G");
for (int index = 0; index < dataline.length; index++) {
if (count == 0)
{
currentByte = dataline[index];
addToDoc(rleString, currentByte);
count = (byte)(count + 1);
}
else if ((count < 255) && (currentByte == dataline[index]))
{
count = (byte)(count + 1);
}
else
{
addToDoc(rleString, count);
count = 0;
currentByte = dataline[index];
addToDoc(rleString, currentByte);
count = (byte)(count + 1);
}
}
if (count > 0) {
addToDoc(rleString, count);
}
if (rleString.size() > dataline.length + 1)
{
rleString.reset();
addToDoc(rleString, "U");
for (int item = 0; item < dataline.length; item++) {
addToDoc(rleString, dataline[item]);
}
}
return rleString.toByteArray();
}
但我不明白为什么它不起作用
最后,我尝试使用How can I print an image on a Bluetooth printer in Android?与相同的算法作为指南,但仍然打印随机奇怪的符号.
最佳答案 而不是浪费时间反编译一些apk,为什么不看看官方SDK？在制造商网页
Downloads & Drivers上有一个指向
Java SDK的链接,其中包含一个源Sample.java.在源代码中创建了BufferedImage,所以我猜(我没有这样的打印机),这将为您提供问题的切入点.而且很可能他们在同一页面上提供了Android演示
Printer Demo Source code for Android的源代码
编辑确定.让我们总结一下：你有一个图像,想要打印它.在示例Sample.java中,涵盖了这种情况
BufferedImage newImage = new BufferedImage(1024, 512, BufferedImage.TYPE_4BYTE_ABGR);
// some lines and rectangles are drawn in the image
...
// the image is printed, following the SDK javadoc for DocumentLP.writeImage
// "This will cause the image specified to be printed. Images will be expanded to occupy
// the entire width of the printer, so the correct current width of the printer must be
// specified. Images that are too wide will be cropped, and images that are too narrow
// will be padded on the right."
testDoc.writeImage(newImage, m_PrinterWidth);
对我来说,你唯一需要做的事情是：
>创建一个BufferedImage对象
>将文件从文件中绘制到缓冲图像中
>调用DocumentLP对象的writeImage方法
编辑2个伪代码片段
// taken from SDK javadoc
DocumentLP docLP;
docLP = new DocumentLP("$");
// own code
BufferedInputStream bis = new BufferedInputStream(--from your image--);
BufferedImage bufImage = ImageIO.read(bis);
// have a look into Sample.java for the expected value of m_PrinterWidth
testDoc.writeImage(bufImage, m_PrinterWidth);
编辑Android的3个代码片段(取自datamax o´neil Android SDK提供的DO_AndroidSDKDemo_MainActivity.java
File file = new File(selectedPath);
byte[] readBuffer = new byte[(int)file.length()];
InputStream inputStream= new BufferedInputStream(new FileInputStream(file));
inputStream.read(readBuffer);
inputStream.close();
fileData = readBuffer;
Bitmap m_imageObject = BitmapFactory.decodeByteArray(fileData, 0, fileData.length);
documentLP.clear();
ocumentLP.writeImage(m_imageObject, m_printHeadWidth);
