我正在尝试使用Universal Image Loader将图像保存到外部SD卡。我正在关注来自作者nostra的这个极其过时的代码片段：
Download Image stream from android universal image loader
我有兴趣成功地重新创建它，但是当我尝试时，我得到了
此错误：
06-21 07:56:22.586 17647-17647/as;dlkfa E/libEGL﹕ call to OpenGL ES API with no current context (logged once per thread)
06-21 07:56:27.562 17647-17647/;alsdjf E/ViewRootImpl﹕ sendUserActionEvent() mView == null
06-21 07:56:30.965 17647-17647/;aldjf; E/ViewRootImpl﹕ sendUserActionEvent() mView == null
06-21 07:56:32.737 17647-17647/a;sdjfl E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.NullPointerException
at com.nostra13.universalimageloader.utils.IoUtils.copyStream(IoUtils.java:73)
at com.nostra13.universalimageloader.utils.IoUtils.copyStream(IoUtils.java:50)
at ;a;ldsfkj.MediaDisplayActivity.saveToGallery(MediaDisplayActivity.java:344)
at as;dlkfj.MediaDisplayActivity.onMenuItemClick(MediaDisplayActivity.java:298)
at android.widget.PopupMenu.onMenuItemSelected(PopupMenu.java:142)
at com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:735)
at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:152)
at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:874)
at com.android.internal.view.menu.MenuPopupHelper.onItemClick(MenuPopupHelper.java:175)
at android.widget.AdapterView.performItemClick(AdapterView.java:301)
at android.widget.AbsListView.performItemClick(AbsListView.java:1507)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:3336)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5455)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1187)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
at dalvik.system.NativeStart.main(Native Method)
我已将原始代码更改为此。它在菜单项上单击调用：
private void saveToGallery()
{
String imageUrl = imageUrls.get(pager.getCurrentItem());
File path = Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES);
File fileForImage = new File(path, imageUrl);
InputStream sourceStream = null;
File cachedImage = ImageLoader.getInstance().getDiskCache().get(imageUrl);
if (cachedImage.exists()) { // if image was cached by UIL
try {
sourceStream = new FileInputStream(cachedImage);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
} else { // otherwise - download image
ImageDownloader downloader = new BaseImageDownloader(this);
try {
sourceStream = downloader.getStream(imageUrl, null);
} catch (IOException e) {
e.printStackTrace();
}
}
// TODO : use try-finally to close streams
OutputStream targetStream = null;
try {
targetStream = new FileOutputStream(fileForImage);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
try {
IoUtils.copyStream(sourceStream, targetStream, null);
} catch (IOException e) {
e.printStackTrace();
}
try {
targetStream.close();
} catch (IOException e) {
e.printStackTrace();
}
try {
sourceStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
第344行是：
IoUtils.copyStream(sourceStream, targetStream, null);
阅读修复评论。基本上，我使用的是像https **这样的坏字符：**
此外，这是我的新代码，它可以工作，但它仍然不会为您的应用创建相册，如果您希望用户快速浏览自己的相册，这是非常理想的。我将继续在评论中寻求编码之神的帮助。此外，它在保存相同图像时仍无法处理。
//TODO upon uninstall ensure the files are still there
//TODO make sure this janky stuff don't crash if you save the same stuff twice
private boolean saveToGallery() {
String imageUrl = imageUrls.get(pager.getCurrentItem());
int i = imageUrl.length()-1;
while(imageUrl.charAt(i) != '/')
{
i--;
}
String newImageUrl = imageUrl.substring(i+1);
File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
File fileForImage = new File(path, newImageUrl);
// if (!fileForImage.mkdirs()) {
// Log.e("shit", "Directory not created");
// }
boolean saved = false;
InputStream sourceStream = null;
File cachedImage = ImageLoader.getInstance().getDiskCache().get(imageUrl);
try {
if (cachedImage != null && cachedImage.exists()) { // if image was cached by UIL
sourceStream = new FileInputStream(cachedImage);
} else { // otherwise - download image
ImageDownloader downloader = new BaseImageDownloader(this);
sourceStream = downloader.getStream(imageUrl, null);
}
} catch (IOException e) {
L.e(e);
}
if (sourceStream != null) {
try {
System.out.println(fileForImage.getAbsolutePath());
OutputStream targetStream = new FileOutputStream(fileForImage);
IoUtils.copyStream(sourceStream, targetStream, null);
targetStream.close();
sourceStream.close();
saved = true;
} catch (IOException e) {
L.e(e);
}
}
//Updates the gallery, dunno how though lol, yay SO
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + Environment.getExternalStorageDirectory())));
return saved;
}
大家好，我所要做的就是在追加url文件之前移动mkdirs（）调用。我现在太累了，不知道事情的顺序，但肯定是因为这个。这是新代码。如果你使用通用图片加载器和文件名的URL的一部分，这将把图像保存到你的应用程序中的相册，否则，没有汤给你：
//TODO upon uninstall ensure the files are still there
//TODO make sure this janky stuff don't crash if you save the same stuff twice
private boolean saveToGallery() {
String imageUrl = imageUrls.get(pager.getCurrentItem());
int i = imageUrl.length()-1;
while(imageUrl.charAt(i) != '/')
{
i--;
}
String newImageUrl = imageUrl.substring(i+1);
File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES + "/Your app name here");
if (!path.mkdirs()) {
Log.e("shit", "Directory not created");
}
File fileForImage = new File(path, newImageUrl);
boolean saved = false;
InputStream sourceStream = null;
File cachedImage = ImageLoader.getInstance().getDiskCache().get(imageUrl);
try {
if (cachedImage != null && cachedImage.exists()) { // if image was cached by UIL
sourceStream = new FileInputStream(cachedImage);
} else { // otherwise - download image
ImageDownloader downloader = new BaseImageDownloader(this);
sourceStream = downloader.getStream(imageUrl, null);
}
} catch (IOException e) {
L.e(e);
}
if (sourceStream != null) {
try {
System.out.println(fileForImage.getAbsolutePath());
OutputStream targetStream = new FileOutputStream(fileForImage);
IoUtils.copyStream(sourceStream, targetStream, null);
targetStream.close();
sourceStream.close();
saved = true;
} catch (IOException e) {
L.e(e);
}
}
//Updates the gallery, dunno how though lol, yay SO
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + Environment.getExternalStorageDirectory())));
return saved;
}
答案 0 :(得分：2)
我重构了您的方法，如果保存到图库失败则返回false：
private boolean saveToGallery() {
String imageUrl = imageUrls.get(pager.getCurrentItem());
File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
File fileForImage = new File(path, imageUrl);
boolean saved = false;
InputStream sourceStream = null;
File cachedImage = ImageLoader.getInstance().getDiskCache().get(imageUrl);
try {
if (cachedImage != null && cachedImage.exists()) { // if image was cached by UIL
sourceStream = new FileInputStream(cachedImage);
} else { // otherwise - download image
ImageDownloader downloader = new BaseImageDownloader(this);
sourceStream = downloader.getStream(imageUrl, null);
}
} catch (IOException e) {
L.e(e);
}
if (sourceStream != null) {
try {
OutputStream targetStream = new FileOutputStream(fileForImage);
try {
IoUtils.copyStream(sourceStream, targetStream, null);
saved = true;
} catch (IOException e) {
L.e(e);
} finally {
targetStream.close();
}
} catch (IOException e) {
L.e(e);
} finally {
sourceStream.close();
}
}
return saved;
}
答案 1 :(得分：1)
用户####很高兴为您提供帮助。如果所有的OP都是健谈的并且通知！