安卓学习第25课——imageswitcher

使用ImageSwitcher，实现渐变效果更换图片

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center_horizontal">

    <GridView
        android:id="@+id/gridView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:horizontalSpacing="2pt"
        android:verticalSpacing="2pt"
        android:gravity="center"
        android:numColumns="4" >
    </GridView>
    <ImageSwitcher
        android:id="@+id/imageSwitcher1"
        android:layout_width="300dp"
        android:layout_height="300dp"
        android:layout_gravity="center_horizontal"
        android:inAnimation="@android:anim/fade_in"
        android:outAnimation="@android:anim/fade_out"
         >
    </ImageSwitcher>

</LinearLayout>

package com.example.imageswitcher;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.GridView;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.SimpleAdapter;
import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity {
int[] imageIds=new int[]{
    R.drawable.bomb5,R.drawable.bomb6,R.drawable.bomb7,R.drawable.bomb8,
    R.drawable.bomb9,R.drawable.bomb10,R.drawable.bomb11,R.drawable.bomb12,
    R.drawable.bomb13,R.drawable.bomb14,R.drawable.bomb15,R.drawable.bomb16
};
    ImageSwitcher switcher;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        List<Map<String,Object>> listItems=new ArrayList<Map<String,Object>>();
        for(int i=0;i<imageIds.length;i++){
            Map<String,Object> listItem=new HashMap<String,Object>();
            listItem.put("image", imageIds[i]);
            listItems.add(listItem);
        }
        switcher=(ImageSwitcher) findViewById(R.id.imageSwitcher1);
        switcher.setFactory(new ViewFactory(){

            @Override
            public View makeView() {
                ImageView imageView=new ImageView(MainActivity.this);
                imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
                imageView.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT));
                return imageView;
            }

        });
        SimpleAdapter simpleAdapter=new SimpleAdapter(this, listItems, R.layout.cell, new String[]{"image"}, new int[]{R.id.image1});
    GridView grid=(GridView) findViewById(R.id.gridView);
    grid.setAdapter(simpleAdapter);
    grid.setOnItemSelectedListener(new OnItemSelectedListener(){

        @Override
        public void onItemSelected(AdapterView<?> parent, View view,
                int position, long id) {
            switcher.setImageResource(imageIds[position]);
        }
        @Override
        public void onNothingSelected(AdapterView<?> parent) {
        }

    });
    grid.setOnItemClickListener(new OnItemClickListener(){

        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position,
                long id) {
            switcher.setImageResource(imageIds[position]);
        }});
    }
}