then I added one head file, compile again, many error come as follow? my question: why after added one file. some error come?
Arduino: 1.6.7 (Windows 10), Board: "Arduino/Genuino Uno"
sketch\graphicstest.ino.cpp.o: In function `__static_initialization_and_destruction_0':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:26: undefined reference to `Adafruit_ILI9341::Adafruit_ILI9341(signed char, signed char, signed char)'
sketch\graphicstest.ino.cpp.o: In function `testFillScreen()':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:112: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:113: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:114: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:115: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:116: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
sketch\graphicstest.ino.cpp.o:C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:121: more undefined references to `Adafruit_ILI9341::fillScreen(unsigned int)' follow
sketch\graphicstest.ino.cpp.o: In function `loop':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:104: undefined reference to `Adafruit_ILI9341::setRotation(unsigned char)'
sketch\graphicstest.ino.cpp.o: In function `testLines(unsigned int)':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:153: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:163: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:174: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:185: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
sketch\graphicstest.ino.cpp.o: In function `testRects(unsigned int)':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:216: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
sketch\graphicstest.ino.cpp.o:C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:251: more undefined references to `Adafruit_ILI9341::fillScreen(unsigned int)' follow
sketch\graphicstest.ino.cpp.o: In function `testTriangles()':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:293: undefined reference to `Adafruit_ILI9341::color565(unsigned char, unsigned char, unsigned char)'
sketch\graphicstest.ino.cpp.o: In function `testFilledTriangles()':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:304: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:309: undefined reference to `Adafruit_ILI9341::color565(unsigned char, unsigned char, unsigned char)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:312: undefined reference to `Adafruit_ILI9341::color565(unsigned char, unsigned char, unsigned char)'
sketch\graphicstest.ino.cpp.o: In function `testRoundRects()':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:324: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:329: undefined reference to `Adafruit_ILI9341::color565(unsigned char, unsigned char, unsigned char)'
sketch\graphicstest.ino.cpp.o: In function `testFilledRoundRects()':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:341: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:345: undefined reference to `Adafruit_ILI9341::color565(unsigned char, unsigned char, unsigned char)'
sketch\graphicstest.ino.cpp.o: In function `testFastLines(unsigned int, unsigned int)':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:202: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:204: undefined reference to `Adafruit_ILI9341::drawFastHLine(int, int, int, unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:205: undefined reference to `Adafruit_ILI9341::drawFastVLine(int, int, int, unsigned int)'
sketch\graphicstest.ino.cpp.o: In function `testFilledRects(unsigned int, unsigned int)':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:233: undefined reference to `Adafruit_ILI9341::fillScreen(unsigned int)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:238: undefined reference to `Adafruit_ILI9341::fillRect(int, int, int, int, unsigned int)'
sketch\graphicstest.ino.cpp.o: In function `setup':
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:34: undefined reference to `Adafruit_ILI9341::begin()'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:37: undefined reference to `Adafruit_ILI9341::readcommand8(unsigned char, unsigned char)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:39: undefined reference to `Adafruit_ILI9341::readcommand8(unsigned char, unsigned char)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:41: undefined reference to `Adafruit_ILI9341::readcommand8(unsigned char, unsigned char)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:43: undefined reference to `Adafruit_ILI9341::readcommand8(unsigned char, unsigned char)'
C:\JimWang\ElectronicsProject\Adafruit_ILI9341-master\examples\graphicstest/graphicstest.ino:45: undefined reference to `Adafruit_ILI9341::readcommand8(unsigned char, unsigned char)'
collect2.exe: error: ld returned 1 exit status
exit status 1
Error compiling.
This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.