【发布时间】：2015-12-23 00:32:44
【问题描述】：
我有一个带有适配器的 gridview，当单击 imageview 时，它也有一个复选框外观。但是出了点问题。如果选中了一个图像并且您滚动到底部，则其中一个图像也会被选中。如果您再次向上滚动，则会选中另一张图片而不是您开始点击的图片（在大多数情况下）。
这是我的适配器的代码。关注的代码是 getView 方法：
public class ImageAdapter extends BaseAdapter {
private Context context;
private ArrayList<String> files;
private Bitmap mPlaceHolderBitmap;
private File directory;
private int thumbSize;
private GridImageListener gridImageListener;
private LayoutInflater inflater;
private View rootView;
private final int MAX_PICTURE_LIMIT = 5;
private int picturesChosenCount = 0;
public ImageAdapter(Context context, ArrayList<String> files, File directory, int thumbSize, GridImageListener gridImageListener, LayoutInflater inflater, View rootView) {
super();
this.context = context;
this.files = files;
this.directory = directory;
this.thumbSize = thumbSize;
this.gridImageListener = gridImageListener;
this.inflater = inflater;
this.rootView = rootView;
mPlaceHolderBitmap = drawableToBitmap(context.getResources().getDrawable(R.drawable.logo));
}
public Bitmap drawableToBitmap (Drawable drawable) {
if (drawable instanceof BitmapDrawable) {
return ((BitmapDrawable)drawable).getBitmap();
}
Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
drawable.draw(canvas);
return bitmap;
}
@Override
public int getCount() {
return files.size();
}
@Override
public Object getItem(int position) {
return files.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup container) {
final ViewHolder holder;
if (convertView == null) { // if it's not recycled, initialize some attributes
holder = new ViewHolder();
convertView = inflater.inflate(R.layout.component_imageview_checkable, null);
holder.imageview = (ImageView) convertView.findViewById(R.id.checkableImageView);
holder.imageview.getLayoutParams().height = thumbSize;
holder.imageview.getLayoutParams().width = thumbSize;
holder.imageCheckBox = (RelativeLayout) convertView.findViewById(R.id.image_check_view);
loadBitmap(files.get(position), holder.imageview);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.imageCheckBox.setId(position);
holder.imageview.setId(position);
holder.imageview.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (holder.imageCheckBox.getVisibility() == View.VISIBLE) {
holder.imageCheckBox.setVisibility(View.INVISIBLE);
picturesChosenCount--;
} else {
if (picturesChosenCount < 5) {
holder.imageCheckBox.setVisibility(View.VISIBLE);
picturesChosenCount++;
} else {
Toast.makeText(context, "Max number of pictures has been reached", Toast.LENGTH_SHORT).show();
}
}
gridImageListener.onClickImage(files.get(position));
}
});
holder.id = position;
return convertView;
}
public void loadBitmap(String path, ImageView imageView) {
if (cancelPotentialWork(path, imageView)) {
final BitmapWorkerTask task = new BitmapWorkerTask(imageView, context, path, directory, thumbSize);
final AsyncDrawable asyncDrawable =
new AsyncDrawable(context.getResources(), mPlaceHolderBitmap, task);
imageView.setImageDrawable(asyncDrawable);
task.execute(path);
}
}
public static boolean cancelPotentialWork(String path, ImageView imageView) {
final BitmapWorkerTask bitmapWorkerTask = getBitmapWorkerTask(imageView);
if (bitmapWorkerTask != null) {
final String bitmapData = bitmapWorkerTask.path;
// If bitmapData is not yet set or it differs from the new data
if (bitmapData.equals("0") || !bitmapData.equals(path)) {
// Cancel previous task
bitmapWorkerTask.cancel(true);
} else {
// The same work is already in progress
return false;
}
}
// No task associated with the ImageView, or an existing task was cancelled
return true;
}
private static BitmapWorkerTask getBitmapWorkerTask(ImageView imageView) {
if (imageView != null) {
final Drawable drawable = imageView.getDrawable();
if (drawable instanceof AsyncDrawable) {
final AsyncDrawable asyncDrawable = (AsyncDrawable) drawable;
return asyncDrawable.getBitmapWorkerTask();
}
}
return null;
}
static class AsyncDrawable extends BitmapDrawable {
private final WeakReference<BitmapWorkerTask> bitmapWorkerTaskReference;
public AsyncDrawable(Resources res, Bitmap bitmap,
BitmapWorkerTask bitmapWorkerTask) {
super(res, bitmap);
bitmapWorkerTaskReference =
new WeakReference<BitmapWorkerTask>(bitmapWorkerTask);
}
public BitmapWorkerTask getBitmapWorkerTask() {
return bitmapWorkerTaskReference.get();
}
}
}
class ViewHolder {
int id;
ImageView imageview;
RelativeLayout imageCheckBox;
}
我知道这与gridview中视图的回收有关，但我不知道如何避免/修复它。每个图像视图在异步任务中单独加载，并在您滚动到它时重新加载。需要看的话，代码在这里：http://pastebin.com/2BcBW7PN
最后，这是我为每个图像的项目的 XML：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/checkableImageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:scaleType="centerCrop"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<RelativeLayout
android:id="@+id/image_check_view"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/checkableImageView"
android:layout_alignTop="@+id/checkableImageView"
android:layout_alignRight="@+id/checkableImageView"
android:layout_alignBottom="@+id/checkableImageView"
android:visibility="invisible">
<com.ivankocijan.magicviews.views.MagicTextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:textColor="@color/white"
android:background="@drawable/blue_border"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
<com.ivankocijan.magicviews.views.MagicTextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/icon_check"
android:textColor="@color/white"
android:textSize="@dimen/txtsize_standard_smaller_icon"
android:padding="4dp"
app:typeFace="@string/icon_font"
android:background="@color/standard_blue"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
</RelativeLayout>
</RelativeLayout>
可能出了什么问题？我已经阅读了所有我能找到的教程，但它们似乎都没有任何区别。
【问题讨论】：
-
试试这个方法来解决你的问题：dj-android.blogspot.in/2013/02/…
标签： android gridview imageview