|
Android example source code file (SaveRestoreState.java)
The SaveRestoreState.java Android example source code/* * Copyright (C) 2007 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.example.android.apis.app; // Need the following import to get access to the app resources, since this // class is in a sub-package. import com.example.android.apis.R; import android.app.Activity; import android.os.Bundle; import android.widget.EditText; import android.widget.TextView; /** * <p>Demonstrates required behavior of saving and restoring dynamic activity * state, so that an activity will restart with the correct state if it is * stopped by the system.</p> * * <p>In general, any activity that has been paused may be stopped by the system * at any time if it needs more resources for the currently running activity. * To handle this, before being paused the * {@link android.app.Activity#onSaveInstanceState onSaveInstanceState()} method is called before * an activity is paused, allowing it to supply its current state. If that * activity then needs to be stopped, upon restarting it will receive its * last saved state in * {@link android.app.Activity#onCreate}.</p> * <p>In this example we are currently saving and restoring the state of the * top text editor, but not of the bottom text editor. You can see the difference * by editing the two text fields, then going to a couple different * applications while the demo is running and then returning back to it. The * system takes care of saving a view's state as long as an id has been * assigned to the view, so we assign an ID to the view being saved but not * one to the view that isn't being saved.</p> * <h4>Demo * App/Activity/Save & Restore State * <h4>Source files * <table class="LinkTable"> <tr> <td class="LinkColumn">src/com.example.android.apis/app/SaveRestoreState.java |
<td class="DescrColumn">The Save/Restore Screen implementation
</tr>
<tr>
<td class="LinkColumn">/res/any/layout/save_restore_state.xml
<td class="DescrColumn">Defines contents of the screen
</tr>
</table>
*/
public class SaveRestoreState extends Activity
{
/**
* Initialization of the Activity after it is first created. Here we use
* {@link android.app.Activity#setContentView setContentView()} to set up
* the Activity's content, and retrieve the EditText widget whose state we
* will save/restore.
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
// Be sure to call the super class.
super.onCreate(savedInstanceState);
// See assets/res/any/layout/save_restore_state.xml for this
// view layout definition, which is being set here as
// the content of our screen.
setContentView(R.layout.save_restore_state);
// Set message to be appropriate for this screen.
((TextView)findViewById(R.id.msg)).setText(R.string.save_restore_msg);
}
/**
* Retrieve the text that is currently in the "saved" editor.
*/
CharSequence getSavedText() {
return ((EditText)findViewById(R.id.saved)).getText();
}
/**
* Change the text that is currently in the "saved" editor.
*/
void setSavedText(CharSequence text) {
((EditText)findViewById(R.id.saved)).setText(text);
}
}
... this post is sponsored by my books ... | |
#1 New Release! |
FP Best Seller |
Copyright 1998-2024 Alvin Alexander, alvinalexander.com
All Rights Reserved.
A percentage of advertising revenue from
pages under the /java/jwarehouse
URI on this website is
paid back to open source projects.