Android 获取手机中某一文件夹下的图片，并以banner的形式上下轮播

1.实现图片上下轮播：

package com.unilife.fridge.haiercommon.ui.view;import android.content.Context;import android.graphics.drawable.Drawable;import android.net.Uri;import android.util.AttributeSet;import android.view.Gravity;import android.view.animation.Animation;import android.view.animation.DecelerateInterpolator;import android.view.animation.TranslateAnimation;import android.widget.FrameLayout;import android.widget.ImageView;import com.unilife.fridge.haiercommon.R;import java.io.File;import java.util.List;/** * Created by wangchm on 2017/12/6. * 图片上下轮播 */public class LooperImageView extends FrameLayout {    private List<String> tipList;    private int curTipIndex = 0;    private long lastTimeMillis ;    private static final int ANIM_DELAYED_MILLIONS = 3 * 1000;    /**  动画持续时长  */    private static final int ANIM_DURATION = 1* 1000;    private Animation anim_out, anim_in;    private ImageView iv_out,iv_in;    public LooperImageView(Context context) {        super(context);        initTipFrame();        initAnimation();    }    public LooperImageView(Context context, AttributeSet attrs) {        super(context, attrs);        initTipFrame();        initAnimation();    }    public LooperImageView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        initTipFrame();        initAnimation();    }    private void initTipFrame() {        iv_out = newImageView();        iv_in = newImageView();//        iv_in = backImageView();        addView(iv_out);        addView(iv_in);    }    private ImageView newImageView(){        ImageView imageView = new ImageView(getContext());        LayoutParams lp = new LayoutParams(                LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT, Gravity.CENTER_VERTICAL);        lp.setMargins(0,0,0,10);        imageView.setLayoutParams(lp);        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);//        imageView.setBackgroundResource(R.drawable.bg_album);//        imageView.setPadding(0,0,0,20);        return imageView;    }    private ImageView backImageView(){        ImageView imageView = new ImageView(getContext());        LayoutParams lp = new LayoutParams(                LayoutParams.MATCH_PARENT-20, LayoutParams.MATCH_PARENT, Gravity.CENTER_VERTICAL);        lp.setMargins(0,10,0,10);        imageView.setLayoutParams(lp);        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);        imageView.setImageAlpha(50);        return imageView;    }    private ImageView inImageView(ImageView view){        LayoutParams layoutParams = (LayoutParams) view.getLayoutParams();        layoutParams.width = LayoutParams.MATCH_PARENT;        layoutParams.height = LayoutParams.MATCH_PARENT;        return view;    }    /**     *  将资源图片转换为Drawable对象     * @param ResId     * @return     */    private Drawable loadDrawable(int ResId) {        Drawable drawable = getResources().getDrawable(ResId);        drawable.setBounds(0, 0, drawable.getMinimumWidth() - 10, drawable.getMinimumHeight() - 10);        return drawable;    }    private void initAnimation() {        anim_out = newAnimation(0, -1);        anim_in = newAnimation(2, 0);        anim_in.setAnimationListener(new Animation.AnimationListener() {            @Override            public void onAnimationStart(Animation animation) {            }            @Override            public void onAnimationRepeat(Animation animation) {            }            @Override            public void onAnimationEnd(Animation animation) {                updateTipAndPlayAnimationWithCheck();            }        });    }    private Animation newAnimation(float fromYValue, float toYValue) {        Animation anim = new TranslateAnimation(Animation.RELATIVE_TO_SELF,0, Animation.RELATIVE_TO_SELF,0,                Animation.RELATIVE_TO_PARENT,fromYValue, Animation.RELATIVE_TO_SELF, toYValue);        this.setBackgroundColor(getResources().getColor(R.color.trans));        anim.setDuration(ANIM_DURATION);        anim.setStartOffset(ANIM_DELAYED_MILLIONS);        anim.setInterpolator(new DecelerateInterpolator());        return anim;    }    private void updateTipAndPlayAnimationWithCheck() {        if (System.currentTimeMillis() - lastTimeMillis < 1000 ) {            return ;        }        lastTimeMillis = System.currentTimeMillis();        updateTipAndPlayAnimation();    }    private void updateTipAndPlayAnimation() {        if (curTipIndex % 2 == 0) {            updateImageTip(iv_out);            iv_in.startAnimation(anim_out);            iv_out.startAnimation(anim_in);            this.bringChildToFront(iv_in);            this.setBackgroundResource(R.drawable.bg_album);        } else {            updateImageTip(iv_in);            iv_out.startAnimation(anim_out);            iv_in.startAnimation(anim_in);            this.bringChildToFront(iv_out);            this.setBackgroundResource(R.drawable.bg_album);        }    }    private void updateImageTip(ImageView tipView) {        String tip = getNextTip();        tipView.setImageURI(Uri.fromFile(new File(tip)));    }    /**     *  获取下一条消息     * @return     */    private String getNextTip() {        if (isListEmpty(tipList)) return null;        return tipList.get(curTipIndex++ % tipList.size());    }    public static boolean isListEmpty(List list) {        return list == null || list.isEmpty();    }    public void setImgTipList(List<String> tipList) {        this.tipList = tipList;        curTipIndex = 0;        updateImageTip(iv_out);        updateTipAndPlayAnimation();    }}

2.主界面及其布局：

<com.unilife.fridge.haiercommon.ui.view.LooperImageView    android:id="@+id/albumLooper"    android:layout_width="match_parent"    android:layout_height="match_parent"></com.unilife.fridge.haiercommon.ui.view.LooperImageView>

主页面调用：

albumLooper = (LooperImageView) view.findViewById(R.id.albumLooper);

albumLooper.setImgTipList(getLocalAlbumPhoto());

获取本地文件夹里的图片：

/** 获取本地图片* */private List<String> localPic = new ArrayList<String>();public List<String> getLocalAlbumPhoto() {    if(localPic != null){        localPic.clear();    }    String name = "";    String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/messageBoard/photoImgs";    File dir = new File(path);    if (dir.exists() && dir.isDirectory()) {        File[] files = dir.listFiles();        if (files != null && files.length > 0) {            for(int i=0;i<files.length;i++){                name = files[i].getAbsolutePath();                localPic.add(name);            }        }    }    return localPic;}