我正在开发一款滑动拼图Android应用，因此我使用GridView显示代表图块的16张图片。其中一个图块将由纯白图像（代表背景）组成。这个想法是，如果用户点击与白色瓷砖相邻的任何瓷砖，则所选瓷砖和白色瓷砖将切换位置。
我试图通过将白色图块设置为用户选择的图块来实现此功能，反之亦然。我在变量masterTilePos中保存了白色瓷砖的位置（从位置15开始），并使用参考R.drawable文件中图像的ImageAdapter Integer数组，将masterValPos处的图像设置为所选索引处的图像，并将所选图像添加到白色图块。但是，当我运行程序时，磁贴只能在第一次成功切换：之后，它无法正常工作，GridView中的磁贴顺序也会被破坏。我想这可能是因为数组只是指实际的图像对象，但我不知道该怎么做呢？我遇到这个问题已经有三天了。这是我的代码：
//GRID VIEW
public class MainActivity extends ActionBarActivity {
int masterTilePos = 15;
GridView gridview;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gridview = (GridView) findViewById(R.id.gridview);
gridview.setAdapter(new ImageAdapter(this));
gridview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
//These methods check if a neighboring tile is white, if there is one, swap() is called
if(checkUp(position) || checkDown(position) || checkLeft(position) || checkRight(position)) {
swap(position);
}
}
});
}
public void swap(int pos) {
ImageAdapter updater = new ImageAdapter(this);
//This is where I try to switch the images, and seems to be the source of the problem
int val = updater.mThumbIds[masterTilePos];
updater.mThumbIds[masterTilePos] = updater.mThumbIds[pos];
updater.mThumbIds[pos] = val;
updater.notifyDataSetChanged();
gridview.setAdapter(updater);
gridview.invalidateViews();
masterTilePos = pos;
}
}
//IMAGE ADAPTER
public class ImageAdapter extends BaseAdapter {
private Context mContext;
public ImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mThumbIds.length;
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
// if it's not recycled, initialize some attributes
DisplayMetrics metrics = mContext.getResources().getDisplayMetrics();
int width = metrics.widthPixels / 4;
int height = metrics.heightPixels / 4;
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(width, height));
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
imageView.setPadding(1, 1, 1, 1);
}
else {
imageView = (ImageView) convertView;
}
imageView.setImageResource(mThumbIds[position]);
return imageView;
}
// the array containing references to the images
public Integer[] mThumbIds = {
R.drawable.pic1,
R.drawable.pic2,
R.drawable.pic3,
R.drawable.pic4,
R.drawable.pic5,
R.drawable.pic6,
R.drawable.pic7,
R.drawable.pic8,
R.drawable.pic9,
R.drawable.pic10,
R.drawable.pic11,
R.drawable.pic12,
R.drawable.pic13,
R.drawable.pic14,
R.drawable.pic15,
R.drawable.background
};
}
任何人都可以帮我解决这个问题，这样我就能成功切换网格中的图像吗？谢谢。
答案 0 :(得分：4)
在onCreate中你正在做：
gridview.setAdapter(new ImageAdapter(this));
因此，您创建了适配器，而没有将其分配给任何变量。这是错的！
然后，每次交换都会创建新的适配器：
ImageAdapter updater = new ImageAdapter(this);
您将其设置为当前适配器：
gridview.setAdapter(updater);
这也是错误的。
你必须这样做：
然后，如果遇到问题，请在SWAP方法中调试逻辑。
//GRID VIEW
public class MainActivity extends ActionBarActivity {
int masterTilePos = 15;
GridView gridview;
ImageAdapter imageAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gridview = (GridView) findViewById(R.id.gridview);
imageAdapter= new ImageAdapter(this);
gridview.setAdapter(imageAdapter);
gridview.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v,
int position, long id) {
//These methods check if a neighboring tile is white, if there is one, swap() is called
if(checkUp(position) || checkDown(position) || checkLeft(position) || checkRight(position)) {
swap(position);
}
}
});
}
public void swap(int pos) {
//This is where I try to switch the images, and seems to be the source of the problem
int val = imageAdaptor.mThumbIds[masterTilePos];
imageAdapter.mThumbIds[masterTilePos] = imageAdapter.mThumbIds[pos];
imageAdapter.mThumbIds[pos] = val;
imageAdapter.notifyDataSetChanged();
gridview.invalidateViews();
masterTilePos = pos;
}
}
//IMAGE ADAPTER
public class ImageAdapter extends BaseAdapter {
private Context mContext;
public ImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mThumbIds.length;
}
public Object getItem(int position) {
return null;
}
public long getItemId(int position) {
return 0;
}
// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
// if it's not recycled, initialize some attributes
DisplayMetrics metrics = mContext.getResources().getDisplayMetrics();
int width = metrics.widthPixels / 4;
int height = metrics.heightPixels / 4;
imageView = new ImageView(mContext);
imageView.setLayoutParams(new GridView.LayoutParams(width, height));
imageView.setScaleType(ImageView.ScaleType.FIT_XY);
imageView.setPadding(1, 1, 1, 1);
}
else {
imageView = (ImageView) convertView;
}
imageView.setImageResource(mThumbIds[position]);
return imageView;
}
// the array containing references to the images
public Integer[] mThumbIds = {
R.drawable.pic1,
R.drawable.pic2,
R.drawable.pic3,
R.drawable.pic4,
R.drawable.pic5,
R.drawable.pic6,
R.drawable.pic7,
R.drawable.pic8,
R.drawable.pic9,
R.drawable.pic10,
R.drawable.pic11,
R.drawable.pic12,
R.drawable.pic13,
R.drawable.pic14,
R.drawable.pic15,
R.drawable.background
};
}