在ListFragment中使用CursorAdapter造成的内存泄露问题
今天在项目中被一个OutOfMemoryError问题困扰了很久,找了半天才发现是由于在ListFragment中使用CursorAdpater造成了内存泄露,横竖屏的时候每倒一次内存就少几兆,几次之后就会出现OutOfMemoryError,具体原因没去深究
于是想干脆把所有的CursorAdapter都换成BaseAdapter,然后自己在其内部封装一个Cursor来实现,但是这样一搞,以前写的所有Adapter都要得重新写一遍,这工作量有点大了···
这时突然想到CursorAdapter也是继承于BaseAdapter,然后去看了下CursorAdapter的源代码,想到个办法,干脆将其中的很多用不到的代码全部去掉,自己来写了一个精简版的CursorAdapter,取个名字叫CustomCursorAdapter.java
再然后把原来所有继承CursorAdapter的类直接换成CustomCursorAdapter,这样一搞居然还真把问题给解决了,现在不管屏幕翻转多少次,都不会再出现OutOfMemoryError!
CustomCursorAdapter.java
import android.content.Context;import android.database.Cursor;import android.provider.BaseColumns;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;public abstract class CustomCursorAdapter extends BaseAdapter { protected Context mContext; private Cursor mCursor; public CustomCursorAdapter(Context context, Cursor cursor, int flag) { this(context, cursor); } public CustomCursorAdapter(Context context, Cursor cursor) { if (context == null) { throw new NullPointerException("context should not be null"); } this.mContext = context; this.mCursor = cursor; } @Override public int getCount() { if (mCursor != null) { return mCursor.getCount(); } else { return 0; } } @Override public Object getItem(int position) { if (mCursor != null) { mCursor.moveToPosition(position); return mCursor; } else { return null; } } @Override public long getItemId(int position) { if (mCursor != null) { if (mCursor.moveToPosition(position)) { return mCursor.getLong(mCursor.getColumnIndexOrThrow(BaseColumns._ID)); } else { return 0; } } else { return 0; } } @Override public View getView(int position, View convertView, ViewGroup parent) { if (!mCursor.moveToPosition(position)) { throw new IllegalStateException("couldn't move cursor to position " + position); } View v; if (convertView == null) { v = newView(mContext, mCursor, parent); } else { v = convertView; } bindView(v, mContext, mCursor); return v; } public abstract View newView(Context context, Cursor cursor, ViewGroup view); public abstract void bindView(View view, Context context, Cursor cursor); public Cursor getCursor() { return mCursor; }}