How do I call a child method from a parent class?
Let's say I have a ChildFragment class that inherits from ParentFragment. The goal is to have multiple Actions and Fragments with buttons, which are typically used with a single ParentFragment.
When the user clicks the refresh button, he calls the function refresh()
in ParentFragment
. However, the action of actually loading this file is handled by the ChildFragment because each fragment has different content. So I want this ParentFragment to call something on the child, whenever it is executed refresh()
.
How can i do this? Or, if there is a better way to do it, this will help too.
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You need to override the method refresh
in child fragments.
public class PFragment extends Fragment{
protected void refresh(){
//Common stuff here
}
}
In child class ovveride update method
public class CFragment extends PFragment{
public void onClick(){
super.refresh();
}
@Override
protected void refresh(){
//Custom stuff here
}
}
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class ParentFragment() {
protected void refresh() {
// general code when refresh every fragment
}
}
class ChildFragment1 extend ParentFragment {
@Override
public void refresh() {
super.refresh();
// code for refresh child fragment1
}
}
class ChildFragment2 extend ParentFragment {
@Override
public void refresh(); {
super.refresh();
// code for refresh child fragment2
}
}
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If you don't want child classes to update and call super.refresh, define an abstract method in ParentFragment for the downloadFile method, and then implement it in the child (ren) classes:
class ParentFragment {
public void refresh() {
downloadFile();
}
protected abstract void downloadFile();
}
class ChildFragment extends ParentFragment {
@Override
protected void downloadFile() {
// do the download here
}
}
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