What is the difference between notifydatasetinvalidated () and notifydatasetchanged () in Android programs?

The Notifydatasetchanged method controls how the contents of each item are refreshed by forcing calls to GetView if the contents of the adapter are changed by an external method.

public void notifydatasetchanged ()

The method internally implements the invocation of the OnChanged event on top of each observer. This method is called whenever a change in the data set is found, or when a new state of the data is read.

For example, in Sina Weibo, we want to make a display to refresh the Weibo.

public void notifydatasetinvalidated ()

The method internally implements the invocation of the Oninvalidated event on top of each observer. This method is called whenever a data set monitoring change is found, such as if the dataset is no longer valid.

For example, if the data source fails, call notifydatasetinvalidated ()

Notifydatasetinvalidated (), redraw the control (revert to initial state)
Notifydatasetchanged (), redraw the currently visible area