android 顯示目錄下圖片

標籤：

知識點

1. 網格視圖

2. 讀取檔案

MainAcitvity

package com.test.gridview;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.view.View;import android.widget.AdapterView;import android.widget.GridView;import android.widget.Toast;public class MainActivity extends AppCompatActivity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        GridView gridview = (GridView) findViewById(R.id.gridview);        gridview.setAdapter(new ImageAdapter(this));        gridview.setOnItemClickListener(new AdapterView.OnItemClickListener() {            public void onItemClick(AdapterView<?> parent, View v,                                    int position, long id) {                Toast.makeText(MainActivity.this, "" + position,                        Toast.LENGTH_SHORT).show();            }        });    }}

View Code

ImageAdapter

package com.test.gridview;import android.content.Context;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.GridView;import android.widget.ImageView;import java.util.List;import java.util.Map;/** * Created by 1 on 2016/4/17. */public class ImageAdapter extends BaseAdapter {    private Context mContext;    public ImageAdapter(Context c) {        mContext = c;    }    public int getCount() {        return imagePath.size();    }    public Object getItem(int position) {        return null;    }    public long getItemId(int position) {        return 0;    }    // create a new ImageView for each item referenced by the Adapter    public View getView(int position, View convertView, ViewGroup parent) {        ImageView imageView;        if (convertView == null) {            // if it‘s not recycled, initialize some attributes            imageView = new ImageView(mContext);            imageView.setLayoutParams(new GridView.LayoutParams(85, 85));            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);            imageView.setPadding(8, 8, 8, 8);        } else {            imageView = (ImageView) convertView;        }        Bitmap bitmap = BitmapFactory.decodeFile(imagePath.get(position).get(FileUtils.IMAGE_PATH));        imageView.setImageBitmap(bitmap);        return imageView;    }    private List<Map<String, String>> imagePath = FileUtils.getFiles(FileUtils.SDPATH);}

View Code

FileUtils

package com.test.gridview;import android.os.Environment;import java.io.File;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;/** * Created by 1 on 2016/4/17. */public class FileUtils {    public static String[] imageFormatSet = {"jpg", "png", "gif"};    public static String SDPATH = Environment.getExternalStorageDirectory() + "/00Meeting/";    public static String IMAGE_NAME = "imageName";    public static String IMAGE_PATH = "imagePath";    /**     * 判斷是否是圖片檔案     *     * @param path     * @return     */    public static boolean isImageFile(String path) {        for (String format : imageFormatSet) {            if (path.endsWith(format)) {                return true;            }        }        return false;    }    public static List<Map<String, String>> getFiles(String path) {        List<Map<String, String>> pathList = new ArrayList<>();        File file = new File(path);        File[] files = file.listFiles();        for (File f : files) {            if (f.isDirectory()) {                getFiles(f.getAbsolutePath());            } else {                if (isImageFile(f.getPath())) {                    Map<String, String> map = new HashMap<>();                    map.put(FileUtils.IMAGE_NAME, f.getName());                    map.put(FileUtils.IMAGE_PATH, f.getPath());                    pathList.add(map);                }            }        }        return pathList;    }}

View Code

 

android 顯示目錄片