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==== Functions ==== | ==== Functions ==== | ||
The calling sequence is open>query_status>begin>write>end>close. Please notice that: | The calling sequence is open>query_status>begin>write>end>close. Please notice that: | ||
* [[write]] method is used for printing content. | * [[#write]] method is used for printing content. | ||
* print content should be between [[begin]] method and [[end]] method. | * print content should be between [[#begin]] method and [[end]] method. | ||
* [[query_status]] should be between [[open]] method and [[close]] method, but should not be between [[begin]] method and [[end]] method | * [[query_status]] should be between [[open]] method and [[close]] method, but should not be between [[begin]] method and [[end]] method | ||
===== open ===== | ===== open ===== | ||
Revision as of 08:32, 12 April 2018
Functions
The calling sequence is open>query_status>begin>write>end>close. Please notice that:
- #write method is used for printing content.
- print content should be between #begin method and end method.
- query_status should be between open method and close method, but should not be between begin method and end method
open
int printer_open()
Open the printer device.This operation should be used before other operations.
Parameters
Returns
The result code, >= 0, success; <0 error code.
begin
int printer_begin()
Prepare to print, the app should print data after this funciton.
Parameters
Returns
The result code, >= 0, success; <0 error code.
end
int printer_end()
End to print,the begin and end apis are pair operations.
Parameters
Returns
The result code, >= 0, success; <0 error code.
close
int printer_close()
Close the device.The open and close apis are pair operations. If you don’t want to use the device, you should call close to release the device.
Parameters
Returns
The result code, >= 0, success; <0 error code.
query_status
int printer_query_status()
Query the status of the printer.This api should be used inner open and close, but not inner begin and end.
Parameters
Returns
The result code, == 1, has paper; == 0, success; <0 error code.
write
int printer_write(unsigned char* pData, int nDataLength)
Write data to the device. The data can be String, Bitmap data or ESC Commands.
Parameters
| pData | data or ESC command |
| nDataLength | Length of data |
Returns
The result code, >= 0, success; <0 error code.