android - How to set the background colour of individual gridview cells from another activity? -


this code given below want change background color of items in grid view activity.

main.xml

enter code here  <gridview android:id="@+id/students_grid"   android:layout_width="fill_parent"   android:layout_height="fill_parent"   android:numcolumns="6"   android:gravity="center"   android:stretchmode="columnwidth">  </gridview>

main.java

gridview gridview = (gridview) findviewbyid(r.id.students_grid); arrayadapter<string> adapter = new arrayadapter<string>(this,  android.r.layout.simple_list_item_1, student_array); gridview.setadapter(adapter);  ..... public void changegriditemcolor(int position){   view view = gridview.getchildat(position);   view.setbackgroundcolor(color.red);  }

anotheractvity.java

.....  new main().changegriditemcolor(index);  .....

i done getting error call gridview.getchildat(position) on null object i.e. nullpointerexception.. send solution on this. thanks.


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