Activity生命周期[通俗易懂]

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;

public class LifeOfActivity extends Activity
{

    private static final String TAG = "ActivityLife";

    // Called at the start of the full lifetime.
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_life_of);
        Log.e(TAG, "start onCreate~~~");

        // Initialize Activity and inflate the UI.
    }

    // Called after onCreate has finished, use to restore UI state.
    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState)
    {
        super.onRestoreInstanceState(savedInstanceState);
        Log.e(TAG, "start onRestoreInstanceState~~~");

        // Restore UI state from the savedInstanceState.
        // This Bundle has also been passed to onCreate.
        // Will only be called if the Activity has been killed by the system
        // since it was last visible.
    }

    // Called at the start of the visible lifetime.
    @Override
    protected void onStart()
    {
        super.onStart();
        Log.e(TAG, "start onStart~~~");
        // Apply any required UI change now that the Activity is visible.
    }

    // Called before subsequent visible lifetimes for an Activity process.
    @Override
    protected void onRestart()
    {
        super.onRestart();
        Log.e(TAG, "start onRestart~~~");

        // Load changes knowing that the Activity has already been visible
        // within this process.
    }

    // Called at the start of the active lifetime
    @Override
    protected void onResume()
    {
        super.onResume();
        Log.e(TAG, "start onResume~~~");
        // Resume any paused UI updates, threads, or processes required
        // by the Activity but suspended when it was inactive.

    }

    // Called to save UI state changes at the end of the active lifecycle.
    @Override
    protected void onSaveInstanceState(Bundle outState)
    {
        super.onSaveInstanceState(outState);
        Log.e(TAG, "start onSaveInstanceState~~~");

        // Save UI state changes to the outState(savedInstanceState).
        // This Bundle will be passed to onCreate and onRestoreInstanceState if
        // the process is killed and restarted by the run time.
    }

    // Called at the end of the active lifetime.
    @Override
    protected void onPause()
    {
        super.onPause();
        Log.e(TAG, "start onPause~~~");
        // Suspend UI updates, threads, or CPU intensive processes that don't
        // need to be updated when the Activity isn't the active foreground
        // Activity.
    }

    // Called at the end of the visible lifetime.
    @Override
    protected void onStop()
    {
        super.onStop();
        Log.e(TAG, "start onStop~~~");

        // Suspend remaining UI updates, threads, or processing that aren't
        // required when the Activity isn't visible.
        // Persist all edits or state changes as after this call the process if
        // likely to be killed.
    }

    // Sometimes called at the end of the full lifetime.
    @Override
    protected void onDestroy()
    {
        super.onDestroy();
        Log.e(TAG, "start onDestroy~~~");
        // Clean up any resources including ending threads, closing databases
        // connections etc.
    }

}