兩種方式, 推薦方式一html
建立一個 ImageActivityapp
public class ImageActivity extends AppCompatActivity { private static final String TAG = "ImageActivity"; private ImageView iv; Bitmap bitmap; private String mUrl; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_image); iv = (ImageView) findViewById(R.id.iv); // 圖片的url 從另外一個Activity傳過來 String url = getIntent().getStringExtra(EXTRA_URL); mUrl = url; loadImage(url); // 長按 ImageView 把圖片保存到手機 iv.setOnLongClickListener(new View.OnLongClickListener(){ @Override public boolean onLongClick(View v) { download(mUrl) return true; } }); } // 加載並顯示圖片 public void loadImage(String url) { Glide.with(this).load(url).placeholder(R.drawable.image_loading) .diskCacheStrategy(DiskCacheStrategy.SOURCE) .listener(new RequestListener<String, GlideDrawable>() { @Override public boolean onException(Exception e, String model, Target<GlideDrawable> target, boolean isFirstResource) { return false; } @Override public boolean onResourceReady(GlideDrawable resource, String model, Target<GlideDrawable> target, boolean isFromMemoryCache, boolean isFirstResource) { Log.d(TAG, "onResourceReady: mode: " + model); // 若是return true; 則 into(iv) 不起做用, 要手動設置圖片 // iv.setImageDrawable(resource); return false; } }) .into(iv); } // 保存圖片到手機 public void download(final String url) { new AsyncTask<Void, Integer, File>() { @Override protected File doInBackground(Void... params) { File file = null; try { FutureTarget<File> future = Glide .with(ImageActivity.this) .load(url) .downloadOnly(Target.SIZE_ORIGINAL, Target.SIZE_ORIGINAL); file = future.get(); // 首先保存圖片 File pictureFolder = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).getAbsoluteFile(); File appDir = new File(pictureFolder ,"Beauty"); if (!appDir.exists()) { appDir.mkdirs(); } String fileName = System.currentTimeMillis() + ".jpg"; File destFile = new File(appDir, fileName); FileUtil.copy(file, destFile); // 最後通知圖庫更新 sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(new File(destFile.getPath())))); } catch (Exception e) { Log.e(TAG, e.getMessage()); } return file; } @Override protected void onPostExecute(File file) { Toast.makeText(ImageActivity.this, "saved in Pictures/GankBeauty", Toast.LENGTH_SHORT).show(); } @Override protected void onProgressUpdate(Integer... values) { super.onProgressUpdate(values); } }.execute(); } }
以上代碼 從另外一個activity獲得 圖片的 url , 而後使用Glide 圖片加載庫 將圖片顯示到 ImageView上, 長按ImageView能夠將圖片保存到手機的 Pictures/Beauty 目錄中ide
這是基本的代碼模板, 實際狀況更復雜,好比Android 6 還有運行時申請存儲權限的問題。this
還有一種保存圖片的方式也有不少人用,可是通過我對比發現並很差,推薦上面的方式。另外一種方式的代碼以下url
把上面 loadImage 換成 下面的 loadBitmapspa
public void loadBitmap(String url) { Glide.with(this).load(url).asBitmap().placeholder(R.drawable.image_loading) .listener(new RequestListener<String, Bitmap>() { @Override public boolean onException(Exception e, String model, Target<Bitmap> target, boolean isFirstResource) { return false; } @Override public boolean onResourceReady(Bitmap resource, String model, Target<Bitmap> target, boolean isFromMemoryCache, boolean isFirstResource) { Log.i(TAG, "onResourceReady: thread is " + Thread.currentThread().getName()); isReady = true; bitmap = resource; iv.setImageBitmap(resource); return false; } }) .diskCacheStrategy(DiskCacheStrategy.ALL) .into(Target.SIZE_ORIGINAL, Target.SIZE_ORIGINAL); }
把上面的 download 換成下面的 saveImagecode
public void saveImage() { // 首先保存圖片 File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES).getAbsoluteFile(); File appDir = new File(file ,"Beauty"); boolean createed = false; if (!appDir.exists()) { createed = appDir.mkdirs(); } String fileName = System.currentTimeMillis() + ".jpg"; File currentFile = new File(appDir, fileName); FileOutputStream fos = null; try { fos = new FileOutputStream(currentFile); bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fos); fos.flush(); } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { try { if (fos != null) { fos.close(); } } catch (IOException e) { e.printStackTrace(); } } // 最後通知圖庫更新 this.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(new File(currentFile.getPath())))); }
這種方式把圖片變成bitmap , 保存的時候又從新壓縮bitmap 保存到手機。orm
從電腦下載圖片,而後與保存到手機的圖片對比,發現bitmap的方式獲得的圖片體積變大。htm
而第一種方式下載的圖片與從電腦上下載的圖片體積一致,md5一致。blog
因此推薦downloadOnly方式
做者:Panda Fang
出處:http://www.cnblogs.com/lonkiss/p/7119062.html
原創文章,轉載請註明做者和出處,未經容許不可用於商業營利活動