阅读《Android 从入门到精通》（24）——切换图片

切换图片（ImageSwitcher）

java.lang.Object;

android.view.View;

android.widget.ViewGroup;

android.widget.FrameLayout;

android.widget.ViewAnimator;

android.widget.ImageSwitcher;

ImageSwitcher 提供了显示图片以及图片切换的动画，这一块可以应用于制作动感影集。

ImageSwitcher 类方法

ImageSwitcher 和 Gallery 示例

完整工程：http://download.csdn.net/detail/sweetloveft/9428069

ViewFactory下述工程中主要演示了 ImageSwitcher 和 Gallery 的用法，需要注意的是：ViewFactory.makeView 的实现中，ImageView 所要设置的布局类型是 FrameLayout.LayoutParams，除此之外，其他地方出现要设置的参数均为 Gallery.LayoutParams，否则会导致崩溃！

此外还可以学习下，Window 相关的属性

1.MainActivity.java

package com.sweetlover.activity;

import com.sweetlover.imageswitcher.R;

import android.app.Activity;
import android.content.Context;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
import android.view.animation.AnimationUtils;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.FrameLayout;
import android.widget.Gallery.LayoutParams;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;
import android.widget.ViewSwitcher.ViewFactory;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageSwitcher;

@SuppressWarnings("deprecation")
public class MainActivity extends Activity implements ViewFactory,
OnItemSelectedListener {

public class SelfAdapter extends BaseAdapter {

private Context context = null;

public SelfAdapter(Context context) {
super();
this.context = context;
}

@Override
public int getCount() {
// TODO Auto-generated method stub
return pic.length;
}

@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return pic[position];
}

@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
ImageView imageView = new ImageView(context);
LayoutParams param = new LayoutParams(WIDTH, HEIGHT);
imageView.setImageResource(pic[position]);
imageView.setAdjustViewBounds(true);
imageView.setLayoutParams(param);
return imageView;
}
}

private Gallery gallery = null;
private SelfAdapter selfAdapter = null;
private ImageSwitcher imageSwitcher = null;
private FrameLayout.LayoutParams param = null;

private static final int WIDTH = 480;
private static final int HEIGHT = 640;
private static final int BACKGND_COLOR = Color.BLACK;
private static final int IN_ANIM = android.R.anim.fade_in;
private static final int OUT_ANIM = android.R.anim.fade_out;
private static final Integer[] pic = { R.drawable.pic1, R.drawable.pic2,
R.drawable.pic3 };

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);

gallery = (Gallery) findViewById(R.id.gallery);
imageSwitcher = (ImageSwitcher) findViewById(R.id.imageSwitcher);
selfAdapter = new SelfAdapter(this);
imageSwitcher.setFactory(this);
imageSwitcher.setInAnimation(AnimationUtils
.loadAnimation(this, IN_ANIM));
imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
OUT_ANIM));
gallery.setAdapter(selfAdapter);
gallery.setOnItemSelectedListener(this);
}

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position,
long id) {
// TODO Auto-generated method stub
imageSwitcher.setImageResource(pic[position]);
}

@Override
public void onNothingSelected(AdapterView<?> parent) {
// TODO Auto-generated method stub

}

@Override
public View makeView() {
// TODO Auto-generated method stub
ImageView imageView = new ImageView(this);
param = new FrameLayout.LayoutParams(WIDTH, HEIGHT, Gravity.CENTER);
imageView.setBackgroundColor(BACKGND_COLOR);
imageView.setScaleType(ScaleType.CENTER);
imageView.setLayoutParams(param);
return imageView;
}
}

2.activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<TextView
android:id="@+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />

<ImageSwitcher
android:id="@+id/imageSwitcher"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true" />

<Gallery
android:id="@+id/gallery"
android:background="#660000FF"
android:layout_width="match_parent"
android:layout_height="60dp"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:gravity="center_vertical"
android:spacing="15dp" />

</RelativeLayout>

3.AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.sweetlover.imageswitcher"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="19" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity android:name="com.sweetlover.activity.MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>

</manifest>