andriod 缩略图Thumbnails学习
/** * @(#)MainActivity.java * * Copyright XXX.All rights reserved. * This software is the XXX system. * * @Version: XXX * @JDK: jdk 1.6.0.XXX * @Module: androidThumbnail */ /*- History ********************************************** * ID DATE PERSON REASON * 1 2012-7-11 WuChaoWen Created ********************************************** */ package com.example.androidthumbnail; import java.io.File; import java.io.FileInputStream; import java.io.InputStream; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.R.bool; import android.R.integer; import android.annotation.SuppressLint; import android.app.Activity; import android.app.Dialog; import android.content.ContentResolver; import android.content.Context; import android.content.Intent; import android.database.Cursor; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.net.Uri; import android.os.Bundle; import android.provider.MediaStore; import android.provider.MediaStore.Images.Media; import android.provider.MediaStore.Images.Thumbnails; import android.util.Log; import android.view.View; import android.view.Window; import android.view.View.OnClickListener; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.Button; import android.widget.GridView; import android.widget.ImageView; import android.widget.ListAdapter; import android.widget.SimpleAdapter; import android.widget.Toast; /** * Class description goes here. * @author WuChaoWen * @since 2012-7-11 */ public class MainActivity extends Activity { public static String TAG = "Thumbnails"; public static boolean flag = true; ImageView ivImageShow; private GridView gridView; private ArrayList<HashMap<String, String>> list; private ContentResolver cr; private ArrayList<String> fileList ; public void onCreate(Bundle savedInstanceState) { requestWindowFeature(Window.FEATURE_NO_TITLE);//去除标题 super.onCreate(savedInstanceState); setContentView(R.layout.main); findViews(); } @SuppressLint("ParserError") private void findViews() { ivImageShow = (ImageView)this.findViewById(R.id.ivImageShow); gridView = (GridView) findViewById(R.id.gridview); list = new ArrayList<HashMap<String, String>>(); fileList = new ArrayList<String>(); cr = getContentResolver(); String[] projection = { Thumbnails._ID, Thumbnails.IMAGE_ID, Thumbnails.DATA}; //所要查询的字段 Cursor cursor = cr.query(Thumbnails.EXTERNAL_CONTENT_URI, projection, null, null, null); getColumnData(cursor); // changeFile(); String[] from = { "path" }; int[] to = { R.id.ItemImage }; ListAdapter adapter = new GridAdapter(this, list, R.layout.item, from,to); gridView.setAdapter(adapter); gridView.setOnItemClickListener(listener); } public Uri[] uriArray; private void getColumnData(Cursor cur) { if (cur.moveToFirst()) { int _id; int image_id; String image_path; int _idColumn = cur.getColumnIndex(Thumbnails._ID); int image_idColumn = cur.getColumnIndex(Thumbnails.IMAGE_ID); int dataColumn = cur.getColumnIndex(Thumbnails.DATA); do { // Get the field values _id = cur.getInt(_idColumn); image_id = cur.getInt(image_idColumn); image_path = cur.getString(dataColumn); // Do something with the values. Log.i(TAG, _id + " image_id:" + image_id + " path:" + image_path + "---"); HashMap hash = new HashMap(); hash.put("image_id", image_id + ""); hash.put("path", image_path); list.add(hash); //根据image_id获取真实路径 String path = getFileByImageId(image_id); fileList.add(path); } while (cur.moveToNext()); } } OnItemClickListener listener = new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { // TODO Auto-generated method stub //1.获取选定图片的path String path = ""; String image_id = list.get(position).get("image_id"); Log.i(TAG, "---(^o^)----" + image_id); String[] projection = { Media._ID, Media.DATA }; Cursor cursor = cr.query(Media.EXTERNAL_CONTENT_URI, projection, Media._ID + "=" + image_id, null, null); if (cursor != null) { cursor.moveToFirst(); path = cursor.getString(cursor .getColumnIndex(Media.DATA)); Log.i("path:", path); } else { Toast.makeText(MainActivity.this, "Image doesn't exist!", Toast.LENGTH_SHORT).show(); } //2.以一个对话框来显示图片 // TODO Auto-generated method stub final Dialog dialog = new Dialog(MainActivity.this); // 以对话框形式显示图片 dialog.setContentView(R.layout.image_show); dialog.setTitle("图片显示"); ImageView ivImageShow = (ImageView) dialog.findViewById(R.id.ivImageShow); Button btnClose = (Button) dialog.findViewById(R.id.btnClose); btnClose.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { dialog.dismiss(); } }); Uri uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI.buildUpon(). appendPath(Long.toString(id)).build(); FileUtil file = new FileUtil(); ContentResolver resolver = getContentResolver(); InputStream inputStream = null; // 从Uri中读取图片资源 try { inputStream = new FileInputStream(path); Bitmap bitmap = BitmapFactory.decodeStream(inputStream); ivImageShow.setImageBitmap(bitmap); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } dialog.show(); } }; class GridAdapter extends SimpleAdapter { public GridAdapter(Context context, List<? extends Map<String, ?>> data, int resource, String[] from, int[] to) { super(context, data, resource, from, to); } // set the imageView using the path of image public void setViewImage(ImageView v, String value) { try { Bitmap bitmap = BitmapFactory.decodeFile(value); Bitmap newBit = Bitmap .createScaledBitmap(bitmap, 100, 80, true); v.setImageBitmap(newBit); } catch (NumberFormatException nfe) { v.setImageURI(Uri.parse(value)); } } } //整理缩略图的uri转成file并归类 public String getFileByImageId(int image_id){ String path = ""; Log.i(TAG, "---(^o^)----" + image_id); String[] projection = { Media._ID, Media.DATA }; Cursor cursor2 = cr.query(Media.EXTERNAL_CONTENT_URI, projection, Media._ID + "=" + image_id, null, null); if (cursor2 != null) { cursor2.moveToFirst(); path = cursor2.getString(cursor2 .getColumnIndex(Media.DATA)); Log.i("path:", path); } else { Toast.makeText(MainActivity.this, "Image doesn't exist!", Toast.LENGTH_SHORT).show(); } return path; } }