FILE.CPP：我正在使用这个文件并使用它我创建了对象＆＃34; myFile＆＃34;
/*
SD - a slightly more friendly wrapper for sdfatlib
This library aims to expose a subset of SD card functionality
in the form of a higher level "wrapper" object.
License: GNU General Public License V3
(Because sdfatlib is licensed with this.)
(C) Copyright 2010 SparkFun Electronics
*/
#include <SD.h>
/* for debugging file open/close leaks
uint8_t nfilecount=0;
*/
File::File(SdFile f,
const char *n) {
// oh man you are kidding me, new() doesnt exist? Ok we do it by hand!
_file=(SdFile *)malloc(sizeof(SdFile));
if (_file) {
memcpy(_file, &f, sizeof(SdFile));
strncpy(_name, n, 12);
_name[12]=0;
/* for debugging file open/close leaks
nfilecount++;
Serial.print("Created \"");
Serial.print(n);
Serial.print("\": ");
Serial.println(nfilecount, DEC);
*/
}
}
File::File(void) {
_file=0;
_name[0]=0;
//Serial.print("Created empty file object");
}
File::~File(void) {
// Serial.print("Deleted file object");
}
// returns a pointer to the file name
char *File::name(void) {
return _name;
}
// a directory is a special type of file
boolean File::isDirectory(void) {
return (_file && _file->isDir());
}
size_t File::write(uint8_t val) {
return write(&val, 1);
}
size_t File::write(const uint8_t *buf,
size_t size) {
size_t t;
if (!_file) {
setWriteError();
return 0;
}
_file->clearWriteError();
t=_file->write(buf,
size);
if (_file->getWriteError()) {
setWriteError();
return 0;
}
return t;
}
int File::peek() {
if (! _file) return 0;
int c=_file->read();
if (c !=-1) _file->seekCur(-1);
return c;
}
int File::read() {
if (_file) return _file->read();
return -1;
}
// buffered read for more efficient, high speed reading
int File::read(void *buf,
uint16_t nbyte) {
if (_file) return _file->read(buf, nbyte);
return 0;
}
int File::available() {
if (! _file) return 0;
uint32_t n=size() - position();
return n > 0X7FFF ? 0X7FFF: n;
}
void File::flush() {
if (_file) _file->sync();
}
boolean File::seek(uint32_t pos) {
if (! _file) return false;
return _file->seekSet(pos);
}
uint32_t File::position() {
if (! _file) return -1;
return _file->curPosition();
}
uint32_t File::size() {
if (! _file) return 0;
return _file->fileSize();
}
void File::close() {
if (_file) {
_file->close();
free(_file);
_file=0;
/* for debugging file open/close leaks
nfilecount--;
Serial.print("Deleted ");
Serial.println(nfilecount, DEC);
*/
}
}
File::operator bool() {
if (_file) return _file->isOpen();
return false;
}
我正在尝试使用read制作SD卡write package Simulink。这里发生的是我将SD.cpp和SD.h以及其他必需的files并创建一个wrapper file，其中包含所需的操作（即读取和写入SD卡）和我收到以下错误
SDcard_wrapper.cpp: In function 'void SDcard_Update_wrapper(const boolean_T*, real_T*, const uint8_T*, int_T)':
./SDcard_wrapper.cpp:113: error: no match for 'operator=' in 'myFile = SDClass::open(const char*, uint8_t)(((const char*)"test.txt"), 19u)'
C:\Users\Samanth\Documents\MATLAB\newSD-trail/utility/SdFat.h:135: note: candidates are: SdFile& SdFile::operator=(const SdFile&)
./SDcard_wrapper.cpp:123: error: could not convert 'myFile' to 'bool'
以下是SDcard_wrapper.cpp错误位置：
myFile = SD.open("test.txt", FILE_WRITE); //This is the line where I am getting 1st error
if (myFile) // this is the point where I am getting the error: could not convert 'myFile' to 'bool'
{
Serial.print("Writing to test.txt...");
myFile.println("testing 1, 2, 3.");
// close the file:
myFile.close();
Serial.println("done.");
} else {
// if the file didn't open, print an error:
Serial.println("error opening test.txt");
}
File SDClass::open(const char* filepath, uint8_t mode) {
/*
Open the supplied file path for reading or writing.
The file content can be accessed via the `file` property of
the `SDClass` object--this property is currently
a standard `SdFile` object from `sdfatlib`.
Defaults to read only.
If `write` is true, default action (when `append` is true) is to
append data to the end of the file.
If `append` is false then the file will be truncated first.
If the file does not exist and it is opened for writing the file
will be created.
An attempt to open a file for reading that does not exist is an
error.
*/
int pathidx;
// do the interative search
SdFile parentdir = getParentDir(filepath, &pathidx);
// no more subdirs!
filepath += pathidx;
if (!filepath[0]) {
// it was the directory itself!
return File(parentdir, "/");
}
// Open the file itself
SdFile file;
// failed to open a subdir!
if (!parentdir.isOpen())
return File();
// there is a special case for the Root directory since its a static dir
if (parentdir.isRoot()) {
if (!file.open(SD.root, filepath, mode)) {
// failed to open the file :(
return File();
}
// dont close the root!
} else {
if (!file.open(parentdir, filepath, mode)) {
return File();
}
// close the parent
parentdir.close();
}
if (mode & (O_APPEND | O_WRITE))
file.seekSet(file.fileSize());
return File(file, filepath);
}
class SdFile : public Print // This is the line pointed above in the second error just for information SdFat.h:135: note: candidates are: SdFile& SdFile::operator=(const SdFile&)
{
public:
/** Create an instance of SdFile. */
SdFile(void): type_(FAT_FILE_TYPE_CLOSED) {}
/**
* writeError is set to true if an error occurs during a write().
* Set writeError to false before calling print() and/or write() and check
* for true after calls to print() and/or write().
*/
//bool writeError;
/**
* Cancel unbuffered reads for this file.
* See setUnbufferedRead()
*/
void clearUnbufferedRead(void) {
flags_ &= ~F_FILE_UNBUFFERED_READ;
}
uint8_t close(void);
uint8_t contiguousRange(uint32_t* bgnBlock, uint32_t* endBlock);
uint8_t createContiguous(SdFile* dirFile, const char* fileName, uint32_t size);
/** \return The current cluster number for a file or directory. */
uint32_t curCluster(void) const {
return curCluster_;
}
/** \return The current position for a file or directory. */
uint32_t curPosition(void) const {
return curPosition_;
}
static void dateTimeCallback(void(*dateTime)(uint16_t* date, uint16_t* time)) {
dateTime_ = dateTime;
}
/**
* Cancel the date/time callback function.
*/
static void dateTimeCallbackCancel(void) {
// use explicit zero since NULL is not defined for Sanguino
dateTime_ = 0;
}