Hack 6 为ViewGroup的子视图添加动画效果

 默认情况下，ViewGroup中的子视图是直接显示出来， 有一个简单的方法可以为这一过程添加动画效果。

      Android提供了LayoutAnimationController类，用于为布局或Layout的子视图添加动画效果，动画效果可以在Java代码中写，也可以在xml中写，Java代码中实现如下：

下面是书中的源码例子：

效果图：

主代码：

主类要继承ListActivity，首先获取ListView的实例，然后调用setLayoutAnimation()方法，传入LayoutAnimationController对象。

package com.manning.androidhacks.hack006;import android.app.ListActivity;import android.os.Bundle;import android.view.animation.AnimationUtils;import android.view.animation.LayoutAnimationController;import android.widget.ArrayAdapter;public class MainActivity extends ListActivity {  @Override  public void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    getListView().setLayoutAnimation(        new LayoutAnimationController(AnimationUtils.loadAnimation(            this, R.anim.list_animation), 5.0f));    setListAdapter(new ArrayAdapter<String>(this,        android.R.layout.simple_list_item_1, Countries.COUNTRIES));  }}

R.anim.list_animation 动画文件：

<?xml version="1.0" encoding="utf-8"?><!--  Copyright (c) 2012 Manning  See the file license.txt for copying permission.--><set xmlns:android="http://schemas.android.com/apk/res/android" >    <alpha        android:duration="50"        android:fromAlpha="0"        android:toAlpha="1" />    <translate        android:duration="100"        android:fromYDelta="-100%"        android:toYDelta="0%" /></set>

Countries.COUNTRIES类文件，作为listview数据源

package com.manning.androidhacks.hack006;public class Countries {  public static final String[] COUNTRIES = new String[] {      "Afghanistan", "Albania", "Algeria", "American Samoa", "Andorra",      "Angola", "Anguilla", "Antarctica", "Antigua and Barbuda",      "Argentina", "Armenia", "Aruba", "Australia", "Austria",      "Azerbaijan", "Bahrain", "Bangladesh", "Barbados", "Belarus",      "Belgium", "Belize", "Benin", "Bermuda", "Bhutan", "Bolivia",      "Bosnia and Herzegovina", "Botswana", "Bouvet Island", "Brazil",      "British Indian Ocean Territory", "British Virgin Islands",      "Brunei", "Bulgaria", "Burkina Faso", "Burundi", "Cote d'Ivoire",      "Cambodia", "Cameroon", "Canada", "Cape Verde", "Cayman Islands",      "Central African Republic", "Chad", "Chile", "China",      "Christmas Island", "Cocos (Keeling) Islands", "Colombia",      "Comoros", "Congo", "Cook Islands", "Costa Rica", "Croatia",      "Cuba", "Cyprus", "Czech Republic",      "Democratic Republic of the Congo", "Denmark", "Djibouti",      "Dominica", "Dominican Republic", "East Timor", "Ecuador",      "Egypt", "El Salvador", "Equatorial Guinea", "Eritrea",      "Estonia", "Ethiopia", "Faeroe Islands", "Falkland Islands",      "Fiji", "Finland", "Former Yugoslav Republic of Macedonia",      "France", "French Guiana", "French Polynesia",      "French Southern Territories", "Gabon", "Georgia", "Germany",      "Ghana", "Gibraltar", "Greece", "Greenland", "Grenada",      "Guadeloupe", "Guam", "Guatemala", "Guinea", "Guinea-Bissau",      "Guyana", "Haiti", "Heard Island and McDonald Islands",      "Honduras", "Hong Kong", "Hungary", "Iceland", "India",      "Indonesia", "Iran", "Iraq", "Ireland", "Israel", "Italy",      "Jamaica", "Japan", "Jordan", "Kazakhstan", "Kenya", "Kiribati",      "Kuwait", "Kyrgyzstan", "Laos", "Latvia", "Lebanon", "Lesotho",      "Liberia", "Libya", "Liechtenstein", "Lithuania", "Luxembourg",      "Macau", "Madagascar", "Malawi", "Malaysia", "Maldives", "Mali",      "Malta", "Marshall Islands", "Martinique", "Mauritania",      "Mauritius", "Mayotte", "Mexico", "Micronesia", "Moldova",      "Monaco", "Mongolia", "Montserrat", "Morocco", "Mozambique",      "Myanmar", "Namibia", "Nauru", "Nepal", "Netherlands",      "Netherlands Antilles", "New Caledonia", "New Zealand",      "Nicaragua", "Niger", "Nigeria", "Niue", "Norfolk Island",      "North Korea", "Northern Marianas", "Norway", "Oman", "Pakistan",      "Palau", "Panama", "Papua New Guinea", "Paraguay", "Peru",      "Philippines", "Pitcairn Islands", "Poland", "Portugal",      "Puerto Rico", "Qatar", "Reunion", "Romania", "Russia", "Rwanda",      "Sqo Tome and Principe", "Saint Helena", "Saint Kitts and Nevis",      "Saint Lucia", "Saint Pierre and Miquelon",      "Saint Vincent and the Grenadines", "Samoa", "San Marino",      "Saudi Arabia", "Senegal", "Seychelles", "Sierra Leone",      "Singapore", "Slovakia", "Slovenia", "Solomon Islands",      "Somalia", "South Africa",      "South Georgia and the South Sandwich Islands", "South Korea",      "Spain", "Sri Lanka", "Sudan", "Suriname",      "Svalbard and Jan Mayen", "Swaziland", "Sweden", "Switzerland",      "Syria", "Taiwan", "Tajikistan", "Tanzania", "Thailand",      "The Bahamas", "The Gambia", "Togo", "Tokelau", "Tonga",      "Trinidad and Tobago", "Tunisia", "Turkey", "Turkmenistan",      "Turks and Caicos Islands", "Tuvalu", "Virgin Islands", "Uganda",      "Ukraine", "United Arab Emirates", "United Kingdom",      "United States", "United States Minor Outlying Islands",      "Uruguay", "Uzbekistan", "Vanuatu", "Vatican City", "Venezuela",      "Vietnam", "Wallis and Futuna", "Western Sahara", "Yemen",      "Yugoslavia", "Zambia", "Zimbabwe" };}

源码下载地址：
listview动画 - 下载频道 - CSDN.NET
http://download.csdn.net/detail/xiaobijia/8086703

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