1.I want convert only Sheet metal part flat pattern (sldprt) to dxf . OR
There are many macros on this forum to export flat pattern from sheet metal parts only. You can also try #TASK tool.
2.I want to convert only sheet metal flat pattern view from drawing (slddrw )to dxf
For this you can loop thru all views and get the type. If the view is flat pattern view then you can export that sheet OR get the model details from the view and export flat pattern from model.