将Viewpager与MediaPlayer一起使用 [英] Using Viewpager with MediaPlayer
问题描述
我正在尝试将Viewpager与Mediaplayer一起使用，但遇到了一些问题.设置我的应用程序时，您可以在gridview中单击视频，然后在屏幕上可见时它将开始播放视频.当我第一次打开视频时，它可以正常播放. viewpager在左边或右边的两页中工作.但是，当我经过该应用程序时，它会冻结并崩溃.
I'm trying to use a viewpager with a mediaplayer and i'm running into some issues. My app is set up where you click on a video in the gridview and then when the screen becomes visable it will start playing the video. When I first open up the video it plays fine. The viewpager works for two pages to the left or right. However when I go over that the app freezes up and crashes.
我设置了一些日志，并在我的pageradapater类中找到了，在调用setPrimaryItem之后，当我调用Mediaplayer.setdisplay(holder)时，有一个IllegalArgumentException，它表示The surface has been relased我已经尝试了一些研究和测试，但是我可以找不到要释放的表面.对我来说，出现此错误似乎很奇怪，但是视频仍然可以播放.我不确定为什么会这样.
I set up some logs and I found in my pageradapater class, right after setPrimaryItem is called there is an IllegalArgumentException when I call Mediaplayer.setdisplay(holder) that says that The surface has been relased I've tried to so some research and testing but I can't find where the surface is being released. It seems weird to me that this error comes up but the video still plays. I'm not sure why this happens.
我最好的猜测是pageradapater在一开始就设置了Viewgroup中的所有页面.这可能是由于在ViewGroup中其他地方设置了表面而引起的某种问题.
My best guess is that the pageradapater sets up all the pages in the Viewgroup at the beginning This might be causing some sort of issues because the surface is being set somewhere else in the ViewGroup.
我正在寻找与此相关的帮助.我的代码在下面
I was looking for some help with this. My code is below
FullImageActivity.java
FullImageActivity.java
public class FullImageActivity extends Activity {
private static final String TAG = "MediaPlayer shit";
//MediaPlayer player;
//SurfaceView surfaceview;
SurfaceHolder surfaceHolder;
Gridview gridview = new Gridview();
int width;
int height;
Cursor cursor;
DisplayImageOptions options;
ViewPager viewpager;
TheViewPager theviewpager;
String path;
int position;
String[] projection = { GridviewData.ROWID, GridviewData.BITMAPPATH, GridviewData.VIDEOFILEPATH};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.image_pager);
Intent i = getIntent();
position = i.getExtras().getInt("position");
path = i.getExtras().getString("videopath");
cursor = getContentResolver().query(MediaStore.Video.Media.EXTERNAL_CONTENT_URI,
gridview.mediaColumns,
MediaStore.Video.Media.DATA + " like ?",
new String[] {Environment.getExternalStorageDirectory().getPath() + "/Reelcam/TheReelcams/%"},
null);
theviewpager = new TheViewPager(cursor, this);
viewpager = (ViewPager) findViewById(R.id.pager);
viewpager.setOffscreenPageLimit(2);
viewpager.setAdapter(theviewpager);
}
@Override
protected void onPause() {
//surfaceview.setVisibility(View.GONE);
if ( theviewpager.player != null )
{
if ( theviewpager.player.isPlaying() )
theviewpager.player.stop();
theviewpager.player.release();
theviewpager.player = null;
}
super.onPause();
}
@Override
protected void onResume() {
//surfaceview.setVisibility(View.VISIBLE);
viewpager.setCurrentItem(position);
super.onResume();
}
@Override
protected void onDestroy() {
cursor.close();
super.onDestroy();
}
}
TheViewPager.java
TheViewPager.java
public class TheViewPager extends PagerAdapter implements OnCompletionListener, Callback, OnPreparedListener {
private static final String TAG = "MediaPlayer shit";
LayoutInflater inflater;
MediaPlayer player;
String vpath;
Cursor cursor;
Activity activity;
LayoutInflater layoutInflater;
boolean hasActiveHolder = false;
FullImageActivity fullimage;
public TheViewPager(Cursor cursor2, Activity activity) {
this.cursor = cursor2;
layoutInflater = activity.getLayoutInflater();
this.activity = activity;
this.fullimage = new FullImageActivity();
}
@Override
public int getCount() {
return cursor.getCount();
}
@Override
public void finishUpdate(ViewGroup container) {
super.finishUpdate(container);
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
@Override
public Object instantiateItem(ViewGroup view, int position) {
View v = layoutInflater.inflate(R.layout.full_image, null, false);
SurfaceView surfaceview = (SurfaceView)v.findViewById(R.id.surfaceview);
SurfaceHolder holder = surfaceview.getHolder();
v.setTag(holder);
((ViewPager) view).addView(v, 0);
return v;
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view.equals(((View) object));
}
@Override
public void setPrimaryItem(ViewGroup container, int position,
Object object) {
Log.i(TAG, "setPrimaryItem");
View view = (View) object;
cursor.moveToPosition(position);
vpath = cursor.getString(cursor.getColumnIndex(MediaStore.Video.Media.DATA));
SurfaceHolder holder = (SurfaceHolder) view.getTag();
player = new MediaPlayer();
try {
player.reset();
player.setDataSource(vpath);
player.setOnCompletionListener(this);
player.setOnPreparedListener(this);
player.setDisplay(holder);
player.prepare();
}
catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (SecurityException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
super.setPrimaryItem(container, position, object);
}
@Override
public void onCompletion(MediaPlayer player) {
Log.i(TAG, "onCompleiton");
if (player != null){
if ( player.isPlaying() )
player.stop();
player.reset();
player.release();
player = null;
}
}
@Override
public void startUpdate(ViewGroup container) {
super.startUpdate(container);
}
@Override
public void onPrepared(MediaPlayer arg0) {
arg0.start();
}
作为旁注，这是我的逻辑:
As a side note here is my logic:
我正在使用InstantiateItem方法设置视图. Android文档说Create the page for the given position将是，所以我假设我将在此处设置视图，稍后将在setPrimaryItem中填充该视图. setPrimaryItem方法的文档说Called to inform the adapter of which item is currently considered to be the "primary", that is the one show to the user as the current page.因为这个原因，我想在这里设置媒体播放器，因为它是唯一可以观看视频的地方.我想我可能会丢失一些东西.
I'm using the instantiateItem method to set up the view. Android documentation says is will Create the page for the given position so I assume I will set up the view here that will later be populated in the setPrimaryItem. The documentation for the setPrimaryItem method says Called to inform the adapter of which item is currently considered to be the "primary", that is the one show to the user as the current page. Because of this I want to set the mediaplayer here because it is the only place the video will be viewed. I think I might be missing something.
推荐答案
ViewPager默认情况下，仅保留与当前页面直接相邻的页面(即当前页面左侧，当前页面，以及当前页面右侧的页面).因此，如果您与视频播放页面相距两页，它将被分离并且不再处于活动状态.您可以通过 ViewPager.setOffscreenPageLimit 高于默认值1.请注意，这确实增加了所需的内存量，不应将其放置得太高-请确保在内存量较小的设备上进行测试.
ViewPagers, by default only keep pages that are directly adjacent to the current page (i.e., the page to the left of the current, the current, and the page to the right of the current). Therefore if you are two pages away from your video playing page, it will be detached and no longer be active. You can change the number of pages kept in memory via the ViewPager.setOffscreenPageLimit to something higher than the default of 1. Note that this does increase the amount of memory needed and shouldn't be put too high - be sure to test on devices with a low amount of memory.
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