API: Difference between revisions
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! scope="row" colspan="2"| Returns | ! scope="row" colspan="2"| Returns | ||
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| int || The result code, >= 0, success; <0 [[Error_code|error code]]. | | int || The result code, >= 0, write success, the data length of writed; <0 [[Error_code|error code]]. | ||
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=== read === | === read === | ||
=== query_voltage === | === query_voltage === |
Revision as of 01:56, 3 May 2018
API Overview
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.
Returns | |
---|---|
int | The result code, >= 0, success; <0 error code. |
begin
int printer_begin()
Prepare to print, the app should print data after this funciton.
Returns | |
---|---|
int | The result code, >= 0, success; <0 error code. |
end
int printer_end()
End to print,the begin and end apis are pair operations.
Returns | |
---|---|
int | 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.
Returns | |
---|---|
int | 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.
Returns | |
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int | 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 | |
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pData | unsigned char*: data or ESC command |
nDataLength | int:Length of data |
Returns | |
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int | The result code, >= 0, write success, the data length of writed; <0 error code. |