Package Com.example.thirdweek;
Import Android.os.Bundle;
Import android.support.v4.app.Fragment;
Import android.support.v4.app.FragmentActivity;
Import Android.support.v4.app.FragmentManager;
Import android.support.v4.app.FragmentTransaction;
Import Android.view.View;
Import Android.view.View.OnClickListener;
Import Android.widget.Button;
public class Mainactivity extends Fragmentactivity {
Private Fragment MyMusic;
Private Fragment downLoad;
Private Fragment mine;
Private Fragment currentfragment;
@Override
protected void OnCreate (Bundle savedinstancestate) {
Super.oncreate (savedinstancestate);
Setcontentview (R.layout.activity_main);
Get control
Button Btnmymusic = (button) Findviewbyid (R.id.btn_my_music);
Button Btndownload = (button) Findviewbyid (r.id.btn_download);
Button Btnmine = (button) Findviewbyid (r.id.btn_mine);
Btnmymusic.setonclicklistener (New Onclicklistener () {
@Override
public void OnClick (View v) {
if (MyMusic = = null) {
MyMusic = new MyMusic ();
}
Jumpfragment (MyMusic, "Music");
}
});
Btndownload.setonclicklistener (New Onclicklistener () {
@Override
public void OnClick (View v) {
if (downLoad = = null) {
DownLoad = new Dwonload ();
}
Jumpfragment (DownLoad, "downLoad");
}
});
Btnmine.setonclicklistener (New Onclicklistener () {
@Override
public void OnClick (View v) {
if (mine = = null) {
Mine = new Mine ();
}
Jumpfragment (Mine, "Mine");
}
});
}
private void Jumpfragment (Fragment Fragment, String tab) {
Fragmentmanager manager = Getsupportfragmentmanager ();
Fragmenttransaction action = Manager.begintransaction ();
if (!fragment.isadded ()) {
Action.add (r.id.fm, fragment);
}
if (currentfragment! = null) {
Action.hide (currentfragment);
}
Action.show (fragment);
Add to recycle stack
Action.addtobackstack (tab);
Action.commit ();
Currentfragment = fragment;
}
}
Building multiple databases requires
Db.execsql ("Drop if Table exists T_user");
android-fragment transaction Add and Hide