回收片段内部的视图未调用OnViewCreate

Question

所以，基本上，正如标题所说。我正在片段中实现一个回收视图，以便在屏幕的一部分创建一个地图。我需要两个页面上的回收视图，但只有一个不起作用。当我在AndroidStudio中运行调试器时，它永远不会到达Adapter类中的重写方法。下面是代码，不幸的是它太多了。我还应该提到

• 项目数是计算的，并且不是零
• 适配器已添加到回收器视图
• 布局管理器已添加到回收器视图

为什么没有调用任何被覆盖的方法？如果您需要更多信息，请告诉我

片段

public class FragmentMap extends Fragment {

// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";

private String mParam1;
private String mParam2;

MapData mapData;
StructureData structures;
public FragmentMap(MapData mapData, StructureData structures)
{
this.mapData = mapData;
this.structures = structures;
}

public FragmentMap() {
// Required empty public constructor
}
public static FragmentMap newInstance(String param1, String param2) {
FragmentMap fragment = new FragmentMap();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_map, container, false);
RecyclerView rv = view.findViewById(R.id.mapRecyclerView);
SelectorAdapter myAdapter = new SelectorAdapter(structures);
MapAdapter mapAdapter = new MapAdapter(mapData);
rv.setAdapter(mapAdapter);
rv.setLayoutManager(new GridLayoutManager(
getActivity(),
MapData.HEIGHT,
GridLayoutManager.HORIZONTAL,
false));
return view;
}
}

适配器

public class MapAdapter extends RecyclerView.Adapter<MapViewHolder>{
MapData mapData;
public MapAdapter(MapData mapData)
{
this.mapData = mapData;
}
@NonNull
@Override
public MapViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
View view = layoutInflater.inflate(R.layout.grid_cell,parent,false);
MapViewHolder myViewHolder = new MapViewHolder(view);
return myViewHolder;
}
@Override
public void onBindViewHolder(@NonNull MapViewHolder holder, int position) {
int row = position % MapData.HEIGHT;
int col = position / MapData.HEIGHT;
MapElement mapElement = mapData.get(row, col);
holder.cellOne.setImageResource(mapElement.getNorthEast());
}
@Override
public int getItemCount() {
Log.d("TAG", "getItemCount: " + MapData.HEIGHT * MapData.WIDTH);
return MapData.HEIGHT * MapData.WIDTH;
}
}

观众

public class MapViewHolder extends RecyclerView.ViewHolder {
ImageView cellOne, cellTwo, cellThree, cellFour, structure;
ConstraintLayout parent;
public MapViewHolder(@NonNull View itemView) {
super(itemView);
cellOne = itemView.findViewById(R.id.imageOne);
cellTwo = itemView.findViewById(R.id.imageTwo);
cellThree = itemView.findViewById(R.id.imageThree);
cellFour = itemView.findViewById(R.id.imageFour);
parent = itemView.findViewById(R.id.parent);
int size = parent.getMeasuredHeight() / MapData.HEIGHT + 1;
ViewGroup.LayoutParams lp = itemView.getLayoutParams();
lp.width = size;
lp.height = size;
}
}

地图数据

public class MapData
{
public static final int WIDTH = 30;
public static final int HEIGHT = 10;
private static final int WATER = R.drawable.ic_water;
private static final int[] GRASS = {R.drawable.ic_grass1, R.drawable.ic_grass2,
R.drawable.ic_grass3, R.drawable.ic_grass4};
private static final Random rng = new Random();
private MapElement[][] grid;
private static MapData instance = null;
public static MapData get()
{
if(instance == null)
{
instance = new MapData(generateGrid());
}
return instance;
}
private static MapElement[][] generateGrid()
{
final int HEIGHT_RANGE = 256;
final int WATER_LEVEL = 112;
final int INLAND_BIAS = 24;
final int AREA_SIZE = 1;
final int SMOOTHING_ITERATIONS = 2;
int[][] heightField = new int[HEIGHT][WIDTH];
for(int i = 0; i < HEIGHT; i++)
{
for(int j = 0; j < WIDTH; j++)
{
heightField[i][j] =
rng.nextInt(HEIGHT_RANGE)
+ INLAND_BIAS * (
Math.min(Math.min(i, j), Math.min(HEIGHT - i - 1, WIDTH - j - 1)) -
Math.min(HEIGHT, WIDTH) / 4);
}
}
int[][] newHf = new int[HEIGHT][WIDTH];
for(int s = 0; s < SMOOTHING_ITERATIONS; s++)
{
for(int i = 0; i < HEIGHT; i++)
{
for(int j = 0; j < WIDTH; j++)
{
int areaSize = 0;
int heightSum = 0;
for(int areaI = Math.max(0, i - AREA_SIZE);
areaI < Math.min(HEIGHT, i + AREA_SIZE + 1);
areaI++)
{
for(int areaJ = Math.max(0, j - AREA_SIZE);
areaJ < Math.min(WIDTH, j + AREA_SIZE + 1);
areaJ++)
{
areaSize++;
heightSum += heightField[areaI][areaJ];
}
}
newHf[i][j] = heightSum / areaSize;
}
}
int[][] tmpHf = heightField;
heightField = newHf;
newHf = tmpHf;
}
MapElement[][] grid = new MapElement[HEIGHT][WIDTH];
for(int i = 0; i < HEIGHT; i++)
{
for(int j = 0; j < WIDTH; j++)
{
MapElement element;
if(heightField[i][j] >= WATER_LEVEL)
{
boolean waterN = (i == 0)          || (heightField[i - 1][j] < WATER_LEVEL);
boolean waterE = (j == WIDTH - 1)  || (heightField[i][j + 1] < WATER_LEVEL);
boolean waterS = (i == HEIGHT - 1) || (heightField[i + 1][j] < WATER_LEVEL);
boolean waterW = (j == 0)          || (heightField[i][j - 1] < WATER_LEVEL);
boolean waterNW = (i == 0) ||          (j == 0) ||         (heightField[i - 1][j - 1] < WATER_LEVEL);
boolean waterNE = (i == 0) ||          (j == WIDTH - 1) || (heightField[i - 1][j + 1] < WATER_LEVEL);
boolean waterSW = (i == HEIGHT - 1) || (j == 0) ||         (heightField[i + 1][j - 1] < WATER_LEVEL);
boolean waterSE = (i == HEIGHT - 1) || (j == WIDTH - 1) || (heightField[i + 1][j + 1] < WATER_LEVEL);
boolean coast = waterN || waterE || waterS || waterW ||
waterNW || waterNE || waterSW || waterSE;
grid[i][j] = new MapElement(
!coast,
choose(waterN, waterW, waterNW,
R.drawable.ic_coast_north, R.drawable.ic_coast_west,
R.drawable.ic_coast_northwest, R.drawable.ic_coast_northwest_concave),
choose(waterN, waterE, waterNE,
R.drawable.ic_coast_north, R.drawable.ic_coast_east,
R.drawable.ic_coast_northeast, R.drawable.ic_coast_northeast_concave),
choose(waterS, waterW, waterSW,
R.drawable.ic_coast_south, R.drawable.ic_coast_west,
R.drawable.ic_coast_southwest, R.drawable.ic_coast_southwest_concave),
choose(waterS, waterE, waterSE,
R.drawable.ic_coast_south, R.drawable.ic_coast_east,
R.drawable.ic_coast_southeast, R.drawable.ic_coast_southeast_concave),
null);
}
else
{
grid[i][j] = new MapElement(
false, WATER, WATER, WATER, WATER, null);
}
}
}
return grid;
}
private static int choose(boolean nsWater, boolean ewWater, boolean diagWater,
int nsCoastId, int ewCoastId, int convexCoastId, int concaveCoastId)
{
int id;
if(nsWater)
{
if(ewWater)
{
id = convexCoastId;
}
else
{
id = nsCoastId;
}
}
else
{
if(ewWater)
{
id = ewCoastId;
}
else if(diagWater)
{
id = concaveCoastId;
}
else
{
id = GRASS[rng.nextInt(GRASS.length)];
}
}
return id;
}
protected MapData(MapElement[][] grid)
{
this.grid = grid;
}
public void regenerate()
{
this.grid = generateGrid();
}
public MapElement get(int i, int j)
{
return grid[i][j];
}
}

地图元素

public class MapElement
{
private final boolean buildable;
private final int terrainNorthWest;
private final int terrainSouthWest;
private final int terrainNorthEast;
private final int terrainSouthEast;
private Structure structure;
public MapElement(boolean buildable, int northWest, int northEast,
int southWest, int southEast, Structure structure)
{
this.buildable = buildable;
this.terrainNorthWest = northWest;
this.terrainNorthEast = northEast;
this.terrainSouthWest = southWest;
this.terrainSouthEast = southEast;
this.structure = structure;
}
public boolean isBuildable()
{
return buildable;
}
public int getNorthWest()
{
return terrainNorthWest;
}
public int getSouthWest()
{
return terrainSouthWest;
}
public int getNorthEast()
{
return terrainNorthEast;
}
public int getSouthEast()
{
return terrainSouthEast;
}
/**
* Retrieves the structure built on this map element.
* @return The structure, or null if one is not present.
*/
public Structure getStructure()
{
return structure;
}
public void setStructure(Structure structure)
{
this.structure = structure;
}
}

Answer 1

您在onCreateView中只初始化了一个RecyclerView，如果您想要两个Recycerview，您只需要以相同的方式初始化第二个。