Android(安卓)gallery实现选中放大的效果

最近也在一点点学习，还是老样子，把新学的知识总结一下，方便以后参考用。

现在大多Android入门教程中，都给大家教了gallery的基本用法，浏览图片时大小一样，比较死板。咱们这里稍微加一点点效果：选中放大。

其实也非常简单，就是在适配器中public View getView(int position, View convertView, ViewGroup parent) {}这个抽象方法中做相应处理即可：选中的设置大一点，未选中的设置小一点！

效果实现如下：

闲话少说，贴代码：

galleryAdapter.java

package com.contacts;import android.content.Context;import android.view.View;import android.view.ViewGroup;import android.view.animation.Animation;import android.view.animation.AnimationUtils;import android.widget.BaseAdapter;import android.widget.Gallery;import android.widget.ImageView;public class galleryAdapter extends BaseAdapter{Context mContext;private int selectItem;private int drawable1[]=new int[] {R.drawable.center,R.drawable.left,R.drawable.right};public galleryAdapter(Context mContext){this.mContext=mContext;}@Overridepublic int getCount() {// TODO Auto-generated method stubreturn Integer.MAX_VALUE;          //这里的目的是可以让图片循环浏览}@Overridepublic Object getItem(int position) {// TODO Auto-generated method stubreturn position;}@Overridepublic long getItemId(int position) {// TODO Auto-generated method stubreturn position;}public void setSelectItem(int selectItem) {if (this.selectItem != selectItem) {                this.selectItem = selectItem;notifyDataSetChanged();               }}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {// TODO Auto-generated method stubImageView imageView=new ImageView(mContext);imageView.setImageResource(drawable1[position%drawable1.length]);//取余，让图片循环浏览if(selectItem==position){    Animation animation = AnimationUtils.loadAnimation(mContext, R.anim.my_scale_action);    //实现动画效果imageView.setLayoutParams(new Gallery.LayoutParams(105,120));  imageView.startAnimation(animation);  //选中时，这是设置的比较大}else{imageView.setLayoutParams(new Gallery.LayoutParams(75,90));//未选中}return imageView;}}

ContactsActivity.java

package com.contacts;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.AdapterView;import android.widget.AdapterView.OnItemSelectedListener;import android.widget.Gallery;import android.widget.ImageSwitcher;import android.widget.ImageView;import android.widget.LinearLayout.LayoutParams;public class ContactsActivity extends Activity implements OnItemSelectedListener {    /** Called when the activity is first created. */private galleryAdapter adapter;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        Gallery gallery=(Gallery)findViewById(R.id.gallery);        adapter=new galleryAdapter(this);        gallery.setAdapter(adapter);       gallery.setSpacing(5);        gallery.setOnItemSelectedListener(this);    }    public void onItemSelected(AdapterView<?> parent, View view, int position,long id) {adapter.setSelectItem(position);  //当滑动时，事件响应，调用适配器中的这个方法。 }@Overridepublic void onNothingSelected(AdapterView<?> arg0) {//抽象方法，必须实现// TODO Auto-generated method stub} }

Main.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <Gallery         android:id="@+id/gallery"         android:layout_width="fill_parent"           android:layout_height="wrap_content"         android:layout_marginTop="30dp"  /> </LinearLayout>

还有个动画的配置文件，这里就不贴了，感兴趣的可以下载全部工程。

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