26.Android 下载图片保存到相册
26.Android 下载图片保存到相册
- Android 下载图片保存到相册
- 前言
- 实现思路
- 自定义Dialog
- 自定义Handler
- 自定义AsyncTask
- AndroidManifest配置权限
- DownloadImageToGalleryActivity
- 效果图
- 源码传送门
前言
有遇到没有这样的一种需求：浏览的大图后，点击保存下载高清原图到相册的需求。
现在的图片缓存大多都是Universal-Imager-Loader为多。但是我们在公司的某些离谱的需求（圈子系的需求，要求每条动态展示的图片不止6张，有一条30多张，直接报了Universal-Imager-Loader的OOM，怎么改配置都不能解决）上，后来调研了Glide和Fresco，发现Glide基本是完虐的节奏。
这里给大家提一个Glide小问题：Glide自带能把图片加载成圆角，Glide加载本地图片不能实现圆角。
实现思路
- 1.自定义一个AsyncTask下载图片
- 2.自定义一个Dialog显示下载进度
- 3.自定义一个Handler刷新Dialog的进度
- 4.下载完成后，保存图片到相册里
自定义Dialog
dialog_progressbar.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" android:gravity="center" android:orientation="horizontal">
<ProgressBar android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:gravity="center" android:padding="10dip" />
<TextView android:id="@+id/load_info_text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:padding="10dip" android:text="正在提交..." android:textColor="#000000" />
</LinearLayout>CustomProgressBarDialog
/** * 自定义进度条Dialog */
public class CustomProgressBarDialog extends Dialog {
private LayoutInflater mInflater;
private Context mContext;
private WindowManager.LayoutParams params;
private View mView;
private TextView promptTV;
public CustomProgressBarDialog(Context context) {
super(context);
this.init(context);
}
public CustomProgressBarDialog(Context context, int themeResId) {
super(context, themeResId);
this.init(context);
}
protected CustomProgressBarDialog(Context context, boolean cancelable, OnCancelListener cancelListener) {
super(context, cancelable, cancelListener);
this.init(context);
}
private void init(Context context) {
requestWindowFeature(Window.FEATURE_NO_TITLE);
this.mContext = context;
this.mInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
this.mView = this.mInflater.inflate(R.layout.dialog_progressbar, null);
setContentView(this.mView);
// 设置window属性
this.params = getWindow().getAttributes();
this.params.gravity = Gravity.CENTER;
// 去背景遮盖
this.params.dimAmount = 0;
this.params.alpha = 1.0f;
// 不能关掉
this.setCancelable(false);
this.getWindow().setAttributes(this.params);
this.promptTV = (TextView) findViewById(R.id.load_info_text);
}
/** * 设置内容 * * @param prompt */
public void setLoadPrompt(String prompt) {
this.promptTV.setText(prompt);
}
}自定义Handler
注意：这里可以参考Handler 通用模板。
private static final int HANDLER_LOADING = 262;
/** * 刷新Dialog显示的进度Handler */
private static class LoadingHandler extends Handler {
private final WeakReference<DownloadImageToGalleryActivity> mActivity;
public LoadingHandler(DownloadImageToGalleryActivity activity) {
mActivity = new WeakReference<>(activity);
}
/** * Subclasses must implement this to receive messages. * * @param msg */
@Override
public void handleMessage(Message msg) {
DownloadImageToGalleryActivity activity = this.mActivity.get();
if (activity != null) {
switch (msg.what) {
case HANDLER_LOADING: {
int progressValue = (int) msg.obj;
activity.dialog.setLoadPrompt(progressValue + "%");
activity.dialog.show();
break;
}
}
}
}
}
private final LoadingHandler loadingHandler = new LoadingHandler(DownloadImageToGalleryActivity.this);自定义AsyncTask
注意：这里可以参考AsyncTask 模板。
/** * 下载图片异步任务 */
public class DownloadImageAsyncTask extends AsyncTask<String, Integer, String> {
private Activity activity;
private String localFilePath;
public DownloadImageAsyncTask(Activity activity) {
super();
this.activity = activity;
}
/** * 对应AsyncTask第一个参数 * 异步操作，不在主UI线程中，不能对控件进行修改 * 可以调用publishProgress方法中转到onProgressUpdate(这里完成了一个handler.sendMessage(...)的过程) * * @param params The parameters of the task. * @return A result, defined by the subclass of this task. * @see #onPreExecute() * @see #onPostExecute * @see #publishProgress */
@Override
protected String doInBackground(String... params) {
// TODO 注意这里
/** * 这里接入你所用的网络框架去下载图片，只要保证this.localFilePath的值有就可以了 */
URL fileUrl = null;
try {
fileUrl = new URL(params[0]);
} catch (MalformedURLException e) {
e.printStackTrace();
}
if (fileUrl == null) return null;
try {
HttpURLConnection connection = (HttpURLConnection) fileUrl.openConnection();
connection.setRequestMethod("GET");
connection.setDoInput(true);
connection.connect();
//计算文件长度
int lengthOfFile = connection.getContentLength();
/** * 不存在SD卡，就放到缓存文件夹内 */
File cacheDir = this.activity.getCacheDir();
File downloadFile = new File(cacheDir, UUID.randomUUID().toString() + ".jpg");
this.localFilePath = downloadFile.getPath();
if (!downloadFile.exists()) {
File parent = downloadFile.getParentFile();
if (parent != null) parent.mkdirs();
}
FileOutputStream output = new FileOutputStream(downloadFile);
InputStream input = connection.getInputStream();
InputStream bitmapInput = connection.getInputStream();
//下载
byte[] buffer = new byte[1024];
int len;
long total = 0;
// 计算进度
while ((len = input.read(buffer)) > 0) {
total += len;
this.publishProgress((int) ((total * 100) / lengthOfFile));
output.write(buffer, 0, len);
}
output.close();
input.close();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
/** * 对应AsyncTask第三个参数 (接受doInBackground的返回值) * 在doInBackground方法执行结束之后在运行，此时已经回来主UI线程当中 能对UI控件进行修改 * * @param string The result of the operation computed by {@link #doInBackground}. * @see #onPreExecute * @see #doInBackground * @see #onCancelled(Object) */
@Override
protected void onPostExecute(String string) {
/** * 设置按钮可用，并隐藏Dialog */
DownloadImageToGalleryActivity.this.saveBT.setEnabled(true);
DownloadImageToGalleryActivity.this.dialog.hide();
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
int screenWidth = metrics.widthPixels;
int screenHeight = metrics.heightPixels;
/** * ImageUtil.decodeScaleImage 解析图片 */
Bitmap bitmap = ImageUtil.decodeScaleImage(this.localFilePath, screenWidth, screenHeight);
DownloadImageToGalleryActivity.this.saveIV.setImageBitmap(bitmap);
/** * 保存图片到相册 */
String imageName = System.currentTimeMillis() + ".jpg";
MediaStore.Images.Media.insertImage(DownloadImageToGalleryActivity.this.getApplicationContext().getContentResolver(), bitmap, imageName, "牙医助理");
Toast.makeText(this.activity, "已保存：" + imageName, Toast.LENGTH_LONG).show();
}
/** * 对应AsyncTask第二个参数 * 在doInBackground方法当中，每次调用publishProgress方法都会中转(handler.sendMessage(...))到onProgressUpdate * 在主UI线程中，可以对控件进行修改 * * @param values The values indicating progress. * @see #publishProgress * @see #doInBackground */
@Override
protected void onProgressUpdate(Integer... values) {
// 主线程Handler实例消息
Message message = DownloadImageToGalleryActivity.this.loadingHandler.obtainMessage();
message.obj = values[0];
message.what = HANDLER_LOADING;
// 给主线程Handler发送消息
DownloadImageToGalleryActivity.this.loadingHandler.handleMessage(message);
}
/** * 运行在主UI线程中，此时是预执行状态，下一步是doInBackground * * @see #onPostExecute * @see #doInBackground */
@Override
protected void onPreExecute() {
super.onPreExecute();
}
/** * <p>Applications should preferably override {@link #onCancelled(Object)}. * This method is invoked by the default implementation of * {@link #onCancelled(Object)}.</p> * <p/> * <p>Runs on the UI thread after {@link #cancel(boolean)} is invoked and * {@link #doInBackground(Object[])} has finished.</p> * * @see #onCancelled(Object) * @see #cancel(boolean) * @see #isCancelled() */
@Override
protected void onCancelled() {
/** * 设置按钮可用 */
DownloadImageToGalleryActivity.this.saveBT.setEnabled(true);
super.onCancelled();
}
}AndroidManifest配置权限
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />DownloadImageToGalleryActivity
activity_download_image_to_grallery.xml
<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" tools:context=".DownloadImageToGrallery">
<TextView android:id="@+id/save_tv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margin="6dp" android:padding="6dp" />
<Button android:id="@+id/save_bt" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_margin="6dp" android:padding="6dp" android:text="保存" />
<ImageView android:id="@+id/save_iv" android:layout_width="360dp" android:layout_height="360dp" android:layout_margin="6dp" />
</LinearLayout>DownloadImageToGalleryActivity
public class DownloadImageToGalleryActivity extends AppCompatActivity implements View.OnClickListener {
private static final String OBJECT_IMAGE_URL = "http://img.blog.csdn.net/20150913233900119";
private Button saveBT;
private ImageView saveIV;
private CustomProgressBarDialog dialog;
/** * Called when a view has been clicked. * * @param v The view that was clicked. */
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.save_bt: {
v.setEnabled(false);
/** * 设置按钮不可用，开始执行任务 */
new DownloadImageAsyncTask(this).execute(OBJECT_IMAGE_URL);
break;
}
}
}
private static final int HANDLER_LOADING = 262;
/** * 刷新Dialog显示的进度Handler */
private static class LoadingHandler extends Handler {
private final WeakReference<DownloadImageToGalleryActivity> mActivity;
public LoadingHandler(DownloadImageToGalleryActivity activity) {
mActivity = new WeakReference<>(activity);
}
/** * Subclasses must implement this to receive messages. * * @param msg */
@Override
public void handleMessage(Message msg) {
DownloadImageToGalleryActivity activity = this.mActivity.get();
if (activity != null) {
switch (msg.what) {
case HANDLER_LOADING: {
int progressValue = (int) msg.obj;
activity.dialog.setLoadPrompt(progressValue + "%");
activity.dialog.show();
break;
}
}
}
}
}
private final LoadingHandler loadingHandler = new LoadingHandler(DownloadImageToGalleryActivity.this);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_download_image_to_grallery);
this.saveBT = (Button) this.findViewById(R.id.save_bt);
this.saveIV = (ImageView) this.findViewById(R.id.save_iv);
((TextView) this.findViewById(R.id.save_tv)).setText(OBJECT_IMAGE_URL);
this.dialog = new CustomProgressBarDialog(this);
this.saveBT.setOnClickListener(this);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_download_image_to_grallery, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
/** * 自定义进度条Dialog */
public class CustomProgressBarDialog extends Dialog {
private LayoutInflater mInflater;
private Context mContext;
private WindowManager.LayoutParams params;
private View mView;
private TextView promptTV;
public CustomProgressBarDialog(Context context) {
super(context);
this.init(context);
}
public CustomProgressBarDialog(Context context, int themeResId) {
super(context, themeResId);
this.init(context);
}
protected CustomProgressBarDialog(Context context, boolean cancelable, OnCancelListener cancelListener) {
super(context, cancelable, cancelListener);
this.init(context);
}
private void init(Context context) {
requestWindowFeature(Window.FEATURE_NO_TITLE);
this.mContext = context;
this.mInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
this.mView = this.mInflater.inflate(R.layout.dialog_progressbar, null);
setContentView(this.mView);
// 设置window属性
this.params = getWindow().getAttributes();
this.params.gravity = Gravity.CENTER;
// 去背景遮盖
this.params.dimAmount = 0;
this.params.alpha = 1.0f;
// 不能关掉
this.setCancelable(false);
this.getWindow().setAttributes(this.params);
this.promptTV = (TextView) findViewById(R.id.load_info_text);
}
/** * 设置内容 * * @param prompt */
public void setLoadPrompt(String prompt) {
this.promptTV.setText(prompt);
}
}
/** * 下载图片异步任务 */
public class DownloadImageAsyncTask extends AsyncTask<String, Integer, String> {
private Activity activity;
private String localFilePath;
public DownloadImageAsyncTask(Activity activity) {
super();
this.activity = activity;
}
/** * 对应AsyncTask第一个参数 * 异步操作，不在主UI线程中，不能对控件进行修改 * 可以调用publishProgress方法中转到onProgressUpdate(这里完成了一个handler.sendMessage(...)的过程) * * @param params The parameters of the task. * @return A result, defined by the subclass of this task. * @see #onPreExecute() * @see #onPostExecute * @see #publishProgress */
@Override
protected String doInBackground(String... params) {
// TODO 注意这里
/** * 这里接入你所用的网络框架去下载图片，只要保证this.localFilePath的值有就可以了 */
URL fileUrl = null;
try {
fileUrl = new URL(params[0]);
} catch (MalformedURLException e) {
e.printStackTrace();
}
if (fileUrl == null) return null;
try {
HttpURLConnection connection = (HttpURLConnection) fileUrl.openConnection();
connection.setRequestMethod("GET");
connection.setDoInput(true);
connection.connect();
//计算文件长度
int lengthOfFile = connection.getContentLength();
/** * 不存在SD卡，就放到缓存文件夹内 */
File cacheDir = this.activity.getCacheDir();
File downloadFile = new File(cacheDir, UUID.randomUUID().toString() + ".jpg");
this.localFilePath = downloadFile.getPath();
if (!downloadFile.exists()) {
File parent = downloadFile.getParentFile();
if (parent != null) parent.mkdirs();
}
FileOutputStream output = new FileOutputStream(downloadFile);
InputStream input = connection.getInputStream();
InputStream bitmapInput = connection.getInputStream();
//下载
byte[] buffer = new byte[1024];
int len;
long total = 0;
// 计算进度
while ((len = input.read(buffer)) > 0) {
total += len;
this.publishProgress((int) ((total * 100) / lengthOfFile));
output.write(buffer, 0, len);
}
output.close();
input.close();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
/** * 对应AsyncTask第三个参数 (接受doInBackground的返回值) * 在doInBackground方法执行结束之后在运行，此时已经回来主UI线程当中 能对UI控件进行修改 * * @param string The result of the operation computed by {@link #doInBackground}. * @see #onPreExecute * @see #doInBackground * @see #onCancelled(Object) */
@Override
protected void onPostExecute(String string) {
/** * 设置按钮可用，并隐藏Dialog */
DownloadImageToGalleryActivity.this.saveBT.setEnabled(true);
DownloadImageToGalleryActivity.this.dialog.hide();
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
int screenWidth = metrics.widthPixels;
int screenHeight = metrics.heightPixels;
/** * ImageUtil.decodeScaleImage 解析图片 */
Bitmap bitmap = ImageUtil.decodeScaleImage(this.localFilePath, screenWidth, screenHeight);
DownloadImageToGalleryActivity.this.saveIV.setImageBitmap(bitmap);
/** * 保存图片到相册 */
String imageName = System.currentTimeMillis() + ".jpg";
MediaStore.Images.Media.insertImage(DownloadImageToGalleryActivity.this.getApplicationContext().getContentResolver(), bitmap, imageName, "牙医助理");
Toast.makeText(this.activity, "已保存：" + imageName, Toast.LENGTH_LONG).show();
}
/** * 对应AsyncTask第二个参数 * 在doInBackground方法当中，每次调用publishProgress方法都会中转(handler.sendMessage(...))到onProgressUpdate * 在主UI线程中，可以对控件进行修改 * * @param values The values indicating progress. * @see #publishProgress * @see #doInBackground */
@Override
protected void onProgressUpdate(Integer... values) {
// 主线程Handler实例消息
Message message = DownloadImageToGalleryActivity.this.loadingHandler.obtainMessage();
message.obj = values[0];
message.what = HANDLER_LOADING;
// 给主线程Handler发送消息
DownloadImageToGalleryActivity.this.loadingHandler.handleMessage(message);
}
/** * 运行在主UI线程中，此时是预执行状态，下一步是doInBackground * * @see #onPostExecute * @see #doInBackground */
@Override
protected void onPreExecute() {
super.onPreExecute();
}
/** * <p>Applications should preferably override {@link #onCancelled(Object)}. * This method is invoked by the default implementation of * {@link #onCancelled(Object)}.</p> * <p/> * <p>Runs on the UI thread after {@link #cancel(boolean)} is invoked and * {@link #doInBackground(Object[])} has finished.</p> * * @see #onCancelled(Object) * @see #cancel(boolean) * @see #isCancelled() */
@Override
protected void onCancelled() {
/** * 设置按钮可用 */
DownloadImageToGalleryActivity.this.saveBT.setEnabled(true);
super.onCancelled();
}
}
}效果图
源码传送门
DownLoadImageToGallery