The file containing the source code shown below is located in the corresponding directory in <sdk>/samples/android-<version>/...
/* * Copyright (C) 2009 The Android开源工程 * * 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.multires; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.ImageView; import android.widget.TextView; public final class MultiRes extends Activity { private int mCurrentPhotoIndex = 0; private int[] mPhotoIds = new int[] { R.drawable.sample_0, R.drawable.sample_1, R.drawable.sample_2, R.drawable.sample_3, R.drawable.sample_4, R.drawable.sample_5, R.drawable.sample_6, R.drawable.sample_7 }; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); showPhoto(mCurrentPhotoIndex); // Handle clicks on the 'Next' button. Button nextButton = (Button) findViewById(R.id.next_button); nextButton.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { mCurrentPhotoIndex = (mCurrentPhotoIndex + 1) % mPhotoIds.length; showPhoto(mCurrentPhotoIndex); } }); } @Override protected void onSaveInstanceState(Bundle outState) { outState.putInt("photo_index", mCurrentPhotoIndex); super.onSaveInstanceState(outState); } @Override protected void onRestoreInstanceState(Bundle savedInstanceState) { mCurrentPhotoIndex = savedInstanceState.getInt("photo_index"); showPhoto(mCurrentPhotoIndex); super.onRestoreInstanceState(savedInstanceState); } private void showPhoto(int photoIndex) { ImageView imageView = (ImageView) findViewById(R.id.image_view); imageView.setImageResource(mPhotoIds[photoIndex]); TextView statusText = (TextView) findViewById(R.id.status_text); statusText.setText(String.format("%d/%d", photoIndex + 1, mPhotoIds.length)); } }