【发布时间】：2012-11-14 05:51:45
【问题描述】：
我遇到了一个相当大的 GridView 的问题。（大约 70 个孩子）如果我在 onCreate 上启动它或在按下主页按钮后恢复然后返回，则 GridView 工作正常。但是当我从睡眠模式恢复后恢复时，我的 BaseAdapter 再次启动并破坏了我在运行时对其所做的更改。如果我在重新启动后调用它，这也会使 getChildAt() 给出 NullPointerException。
我怎样才能让它像常规的 onPause(home button) 一样对 GridView 执行操作，并避免每次从睡眠模式恢复时 GridView 都被清除？
编辑： 我尝试为调用 BaseAdpter 的 Activity 类设置唤醒锁，但没有成功
2.Edit：自从我发布了这个问题以来，我一直在尝试使用 onPause 中的代码恢复 GridView：
SparseArray<Parcelable> array = new SparseArray<Parcelable>();
gridView.saveHierarchyState(array);
bundle = new Bundle();
bundle.putSparseParcelableArray("state", array);
这在 onResume 中：
try{
gridView.restoreHierarchyState(bundle.getSparseParcelableArray("state"));
}
catch(Exception e){
//Most likely first start
Log.i("SomeTag", "No GridView state found");
}
}
奇怪的是我似乎在屏幕上从一个地方跳到另一个地方，当我尝试 getChildAt() 时它仍然崩溃。睡眠模式后也无法获取。
- 编辑这是来自 BaseAdapter getView 的代码（注意！其中一些代码是不相关的）
public View getView (int position, View convertView, ViewGroup parent) {
mParentView = parent;
DisplayMetrics metrics = mContext.getResources().getDisplayMetrics();
int width = metrics.widthPixels;
int height = metrics.heightPixels;
//sets the height for every individual box
int box = width/7*6/10;
ImageCell v = null;
if (convertView == null) {
// If it's not recycled, create a new ImageCell.
v = new ImageCell (mContext);
v.setLayoutParams(new GridView.LayoutParams(box, box));
v.setScaleType(ImageView.ScaleType.CENTER_CROP);
v.setPadding(0, 0, 0, 0);
} else {
v = (ImageCell) convertView;
}
v.mCellNumber = position;
v.mGrid = (GridView) mParentView;
v.mEmpty = true;
int id = 200;
v.setId(++id);
String map = str[position];
int pos = position;
int up = pos-10;
int down = pos+10;
int left = pos-1;
int right = pos+1;
if(up>=0){
above = str[up];
}
else{
//Do nothing
}
if(down<70){
under = str[down];
}
else{
//Do nothing
}
if(left<=-1){
//Do nothing
}
else{
lefte=str[left];
}
if(right>=70){
//Do nothing
}
else{
righte=str[right];
}
//if(left>-1|left!=9|left!=19|left!=29|left!=39|left!=49|left!=59){
// lefte = str[left];
// }
// else{
// Log.i("ImageCellAdapter", "Left is trying to break walls "+left);
//Do nothing
// }
if (map.equals("mountain")) {
//Checks surroundings to find out witch drawable to set
v.setBackgroundResource(R.color.cell_empty);
v.mEmpty = false;
//All
if(above=="mountain"&&under=="mountain"&&lefte=="mountain"&&righte=="mountain"){
v.setImageResource(R.drawable.mountain_full);
}
//Single
else if(above=="mountain"&&under!="mountain"&&lefte!="mountain"&&righte!="mountain"){
v.setImageResource(R.drawable.mountain_down);
}
else if(above!="mountain"&&under=="mountain"&&lefte!="mountain"&&righte!="mountain"){
v.setImageResource(R.drawable.mountain_up);
}
else if(above!="mountain"&&under!="mountain"&&lefte!="mountain"&&righte=="mountain"){
v.setImageResource(R.drawable.mountain_left);
}
else if(above!="mountain"&&under!="mountain"&&lefte=="mountain"&&righte!="mountain"){
v.setImageResource(R.drawable.mountain_right);
}
//Double
else if(above=="mountain"&&under!="mountain"&&lefte!="mountain"&&righte=="mountain"){
v.setImageResource(R.drawable.mountain_left_down);
}
else if(above!="mountain"&&under=="mountain"&&lefte!="mountain"&&righte=="mountain"){
v.setImageResource(R.drawable.mountain_left_up);
}
else if(above=="mountain"&&under!="mountain"&&lefte=="mountain"&&righte!="mountain"){
v.setImageResource(R.drawable.mountain_right_down);
}
else if(above!="mountain"&&under=="mountain"&&lefte=="mountain"&&righte!="mountain"){
v.setImageResource(R.drawable.mountain_up_right);
}
else if(above!="mountain"&&under!="mountain"&&lefte=="mountain"&&righte=="mountain"){
v.setImageResource(R.drawable.mountain_up_down);
}
else if(above=="mountain"&&under=="mountain"&&lefte!="mountain"&&righte!="mountain"){
v.setImageResource(R.drawable.mountain_up_down);
}
//Triple
else if(above!="mountain"&&under=="mountain"&&lefte=="mountain"&&righte=="mountain"){
v.setImageResource(R.drawable.mountain_left_right_down);
}
else if(above=="mountain"&&under=="mountain"&&lefte=="mountain"&&righte!="mountain"){
v.setImageResource(R.drawable.mountain_left_up_down);
}
else if(above=="mountain"&&under!="mountain"&&lefte=="mountain"&&righte=="mountain"){
v.setImageResource(R.drawable.mountain_left_up_right);
}
else if(above=="mountain"&&under=="mountain"&&lefte!="mountain"&&righte=="mountain"){
v.setImageResource(R.drawable.mountain_up_right_down);
}
//None
else{
v.setImageResource(R.drawable.mountain);
}
}
else if(map=="start"){
List<String> posOf = Arrays.asList(str);
startPos=posOf.indexOf("start");
v.mEmpty=false;
v.setBackgroundResource(R.color.cell_empty);
getDur();
BitmapDrawable first = (BitmapDrawable)mContext.getResources().getDrawable(R.drawable.gress);
BitmapDrawable second =(BitmapDrawable)mContext.getResources().getDrawable(R.drawable.ic_launcher);
BitmapDrawable third = (BitmapDrawable)mContext.getResources().getDrawable(R.drawable.gress);
BitmapDrawable fourth = (BitmapDrawable)mContext.getResources().getDrawable(R.drawable.ic_launcher);
final AnimationDrawable ani = new AnimationDrawable();
ani.addFrame(first, duration);
ani.addFrame(second, duration);
ani.addFrame(third, duration);
ani.addFrame(fourth, duration);
ani.setOneShot(true);
v.setImageDrawable(ani);
checkIfAnimationDone(ani);
v.post(new Runnable() {
public void run() {
ani.start();
}
});
}
else if(map=="stop"){
v.mEmpty=false;
v.setBackgroundResource(R.color.cell_empty);
v.setImageResource(R.drawable.ic_launcher);
v.setTag(1);
}
else if(map=="grass"){
v.mEmpty=false;
v.setBackgroundResource(R.drawable.gress);
}
else{
// v.setBackgroundResource (R.color.drop_target_enabled);
v.setBackgroundResource (R.color.cell_empty);
}
//v.mGrid.requestDisallowInterceptTouchEvent (true);
//v.setImageResource (R.drawable.hello);
// Set up to relay events to the activity.
// The activity decides which events trigger drag operations.
// Activities like the Android Launcher require a long click to get a drag operation started.
return v;
}
并在 onCreate 中定义 GridView：
gridView= new BoxView(this);
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH){
w.getDefaultDisplay().getSize(size);
Measuredwidth = size.x;
Measuredheight = size.y;
}else{
Display d = w.getDefaultDisplay();
Measuredwidth = d.getWidth();
Measuredheight = d.getHeight();
}
int width = Measuredwidth/7*6;
gridView.setLayoutParams(new GridView.LayoutParams(width,LayoutParams.FILL_PARENT, Gravity.CENTER_HORIZONTAL));
gridView.setNumColumns(columns);
gridView.setVerticalSpacing(0);
gridView.setHorizontalSpacing(0);
gridView.setPadding(0, 0, 0, 0);
gridView.setId(101);
gridView.setSelector(android.R.color.transparent);
gridView.setAdapter (new ImageCellAdapter(this, MAP));
【问题讨论】：
-
您不想在销毁活动时保留巨大的 GridView，因为这会导致内存不足的情况。你是如何填充视图的？
-
@tad 我必须让它这么大（我正在制作一个基于 GridView 的游戏），它必须始终可见并同时显示所有孩子。使用另一个视图会让我倒退几天。
-
我在问：当您的活动开始时，您是如何填充视图的？来自数据库、保存文件等？
-
@tad 我用 BaseAdapter 填充它。每个孩子都有一个背景资源和一些 ImageResource。这是基于数组的。到目前为止，我没有遇到内存不足的问题。 （我使用每个只使用几个字节的可绘制对象）
-
哦，视图的大小不是问题；它在 Activity 被销毁后保留视图，这是一个问题。在我看来，您需要阅读 Activity 生命周期并在 onPause 方法中保存游戏状态，然后在 onResume/onRestoreInstanceState 方法中填充 gridView。如果您愿意，我可以写一个更详细的真实答案。
标签： android gridview lifecycle android-gridview baseadapter