我需要显示大文本文件。无需滚动即可显示文本，就像电子书一样。我可以在页面上打断长文本，但这会花费我太多时间。例如 - 以下代码处理 1.4 MB 的文本大约需要 10-15 秒。
public void split(TextPaint textPaint, String filepath,Context context) {
int pages = 0;
File file = new File(filepath);
char[] bufferChar = new char[1024];
String uncompletedtext="";
//How lines we can show
int maxLinesOnpage = 0;
StaticLayout staticLayout = new StaticLayout(
context.getString(R.string.lorem_ipsum),
textPaint,
pageWidth,
Layout.Alignment.ALIGN_NORMAL,
lineSpacingMultiplier,
lineSpacingExtra,
false
);
int startLineTop = staticLayout.getLineTop(0);
int endLine = staticLayout.getLineForVertical(startLineTop + pageHeight);
int endLineBottom = staticLayout.getLineBottom(endLine);
if (endLineBottom > startLineTop + pageHeight) {
maxLinesOnpage = endLine - 1;
} else {
maxLinesOnpage = endLine;
}
//let's paginate
try {
BufferedReader buffer = new BufferedReader(new FileReader(file));
while (buffer.read(bufferChar)>=0) {
uncompletedtext += new String(bufferChar);
boolean allcomplete = false;
staticLayout = new StaticLayout(
uncompletedtext,
textPaint,
pageWidth,
Layout.Alignment.ALIGN_NORMAL,
lineSpacingMultiplier,
lineSpacingExtra,
false
);
staticLayout.getLineCount();
int curTextPages= (int) Math.floor(staticLayout.getLineCount() / maxLinesOnpage);
uncompletedtext=uncompletedtext.substring(staticLayout.getLineEnd(curTextPages));
pages+=curTextPages;
Log.e("PAGES","" + pages);
}
} catch (Exception e) {
e.printStackTrace();
}
Log.e("FILE READED FULLY!!", "READ COMPLETE!!!!!!!!!!!!!!!!");
}
太长了。我无法理解 FBReader 和 СoolReader 等应用程序如何立即处理大文件(超过 9 MB)。 我看到了应用程序的源代码，但它们的功能太多，无法快速找到答案。 我真的需要帮助和提示。谢谢。
最佳答案
谢谢大家!我找到解决方案!不优雅但非常快的代码(10Mb ~ 600 ms)
public void split(TextPaint textPaint, String filepath,Context context) {
File file = new File(filepath);
char[] bufferChar = new char[512];
//How lines on page
int maxLinesOnpage = 0;
int symbolsOnLine = 0;
StaticLayout staticLayout = new StaticLayout(
context.getString(R.string.lorem_ipsum),//short text with 100 lines (\r\n\r\n\r\n\r\n\r\n\r\n)
textPaint, //MONOSPACE!!!
pageWidth,
Layout.Alignment.ALIGN_NORMAL,
lineSpacingMultiplier,
lineSpacingExtra,
false
);
int startLineTop = staticLayout.getLineTop(0);
int endLine = staticLayout.getLineForVertical(startLineTop + pageHeight);
int endLineBottom = staticLayout.getLineBottom(endLine);
if (endLineBottom > startLineTop + pageHeight) {
maxLinesOnpage = endLine - 1;
} else {
maxLinesOnpage = endLine;
}
symbolsOnLine = staticLayout.getLineEnd(0);
try {
RandomAccessFile rac = new RandomAccessFile(file, "r");
byte[] buffer = new byte[2048];
int wordLen = 0; //Length of word in symbols
int wordInBytes = 0; //Lenght of word
int startLinePos = 0; //Start first line position
int lineWidth = 0; //Current line length
int totalLines =0; //Total lines on current page
Log.e("Start pagination", "" + totalLines);
long timeout= System.currentTimeMillis();
int buflen=0; //buffer size
int totalReadedBytes = 0; //Total bytes readed
byte skipBytes = 0;
while ( (buflen=rac.read(buffer))!=-1){
for (int i=0;i<buflen;i++) {
totalReadedBytes++;
wordInBytes++;
if (skipBytes==0){ //Bytes on one symbol
if (unsignedToBytes(buffer[i])>=192){skipBytes=2;}
if (unsignedToBytes(buffer[i])>=224){skipBytes=3;}
if (unsignedToBytes(buffer[i])>=240){skipBytes=4;}
if (unsignedToBytes(buffer[i])>=248){skipBytes=5;}
if (unsignedToBytes(buffer[i])>=252){skipBytes=6;}
}
//Full bytes on symbol or not
if (skipBytes>0){
skipBytes--;
if (skipBytes>0){continue;}
}
if (buffer[i] == 13) {//We have a \r symbol. Ignore.
continue;
}
if (buffer[i]==10){//New line symbol
if (lineWidth + wordLen>symbolsOnLine){
totalLines++;
if (totalLines > maxLinesOnpage) {
int[] pgsbytes = {startLinePos, totalReadedBytes};
pages.add(pgsbytes);
startLinePos = totalReadedBytes ;
totalLines = 0;
}
}
wordLen=0;
wordInBytes=0;
totalLines++;
lineWidth=0;
if (totalLines>maxLinesOnpage){
int[] pgsbytes = {startLinePos, totalReadedBytes-1};
pages.add(pgsbytes);
startLinePos = totalReadedBytes-1;
totalLines=0;
}
}
if (buffer[i]==32){//Space symbol
if (lineWidth + wordLen+1<=symbolsOnLine){//Word fits in line
lineWidth+=wordLen + 1;
wordLen=0;
if (lineWidth==symbolsOnLine){
totalLines++;
if (totalLines > maxLinesOnpage) {
int[] pgsbytes = {startLinePos, totalReadedBytes};
pages.add(pgsbytes);
startLinePos = totalReadedBytes ;
totalLines = 0;
}
lineWidth = 0;
wordLen = 0;
wordInBytes=0;
}
} else {
if (lineWidth + wordLen==symbolsOnLine){
totalLines++;
if (totalLines > maxLinesOnpage) {
int[] pgsbytes = {startLinePos, totalReadedBytes};
pages.add(pgsbytes);
startLinePos = totalReadedBytes ;
totalLines = 0;
}
lineWidth = 0;
wordLen = 0;
wordInBytes=0;
} else {
totalLines++;
if (totalLines > maxLinesOnpage) {
int[] pgsbytes = {startLinePos, totalReadedBytes - 1 - wordInBytes};
pages.add(pgsbytes);
startLinePos = totalReadedBytes - 1;
totalLines = 0;
}
lineWidth = wordLen + 1;
wordLen = 0;
wordInBytes=0;
}
}
}
if (buffer[i]!=32&&buffer[i]!=10&&buffer[i]!=13){wordLen++; }
if (wordLen==symbolsOnLine){
totalLines++;
if (totalLines>maxLinesOnpage){
int[] pgsbytes = {startLinePos, totalReadedBytes-1 - wordInBytes};
pages.add(pgsbytes);
startLinePos = totalReadedBytes-1;
totalLines=0;
}
lineWidth=0;
wordLen=0;
wordInBytes=0;
}
}
}
rac.close();
timeout = System.currentTimeMillis() - timeout;
Log.e("TOTAL Time", " time " + timeout + "ms");
} catch (Exception e) {
e.printStackTrace();
}
Log.e("FILE READED FULLY!!", "READ COMPLETE!!!!!!!!!!!!!!!!");
}
关于java - Android长文本分页，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36169561/