Java Adapter.getItemCount方法代码示例

import android.support.v7.widget.RecyclerView.Adapter; //导入方法依赖的package包/类
public void setAdapter(Adapter adapter) {
	if (recyclerView == null) initViews();

	Adapter oldAdapter = recyclerView.getAdapter();
	if (oldAdapter != null) {
		oldAdapter.unregisterAdapterDataObserver(emptyObserver);
	}

	recyclerView.setAdapter(adapter);

	if (adapter != null) {
		adapter.registerAdapterDataObserver(emptyObserver);

		if (adapter.getItemCount() > 0) {
			// only show data if adapter has data already
			// otherwise progress bar is shown
			emptyObserver.onChanged();
		}
	}
}
 

import android.support.v7.widget.RecyclerView.Adapter; //导入方法依赖的package包/类
/**
 * @Description: 判断第一个条目是否完全可见
 *
 * @return boolean:
 * @version 1.0
 * @date 2015-9-23
 * @Author zhou.wenkai
 */
private boolean isFirstItemVisible() {
    final Adapter<?> adapter = getRefreshableView().getAdapter();

    // 如果未设置Adapter或者Adapter没有数据可以下拉刷新
    if (null == adapter || adapter.getItemCount() == 0) {
        if (DEBUG) {
            Log.d(LOG_TAG, "isFirstItemVisible. Empty View.");
        }
        return true;

    } else {
        // 第一个条目完全展示,可以刷新
        if (getFirstVisiblePosition() == 0) {
            return mRefreshableView.getChildAt(0).getTop() >= mRefreshableView
                    .getTop();
        }
    }

    return false;
}
 

import android.support.v7.widget.RecyclerView.Adapter; //导入方法依赖的package包/类
/**
 * @Description: 判断最后一个条目是否完全可见
 *
 * @return boolean:
 * @version 1.0
 * @date 2015-9-23
 * @Author zhou.wenkai
 */
private boolean isLastItemVisible() {
    final Adapter<?> adapter = getRefreshableView().getAdapter();

    // 如果未设置Adapter或者Adapter没有数据可以上拉刷新
    if (null == adapter || adapter.getItemCount() == 0) {
        if (DEBUG) {
            Log.d(LOG_TAG, "isLastItemVisible. Empty View.");
        }
        return true;

    } else {
        // 最后一个条目View完全展示,可以刷新
        int lastVisiblePosition = getLastVisiblePosition();
        if(lastVisiblePosition >= mRefreshableView.getAdapter().getItemCount()-1) {
            return mRefreshableView.getChildAt(
                    mRefreshableView.getChildCount() - 1).getBottom() <= mRefreshableView
                    .getBottom();
        }
    }

    return false;
}
 

import android.support.v7.widget.RecyclerView.Adapter; //导入方法依赖的package包/类
public void showData() {
	if (recyclerView == null) initViews();
	Adapter adapter = recyclerView.getAdapter();
	if (adapter != null) {
		if (adapter.getItemCount() == 0) {
			emptyView.setVisibility(VISIBLE);
			recyclerView.setVisibility(INVISIBLE);
		} else {
			// use GONE here so empty view doesn't use space on small lists
			emptyView.setVisibility(GONE);
			recyclerView.setVisibility(VISIBLE);
		}
		progressBar.setVisibility(GONE);
	}
}
 

import android.support.v7.widget.RecyclerView.Adapter; //导入方法依赖的package包/类
public void onAdapterDataChanged() {
    final Adapter adapter = mRecyclerView.getAdapter();
    if (mChoiceMode == ChoiceMode.NONE || adapter == null || !adapter.hasStableIds()) {
        return;
    }

    final int itemCount = adapter.getItemCount();

    // Clear out the positional check states, we'll rebuild it below from IDs.
    mCheckedStates.clear();

    for (int checkedIndex = 0; checkedIndex < mCheckedIdStates.size(); checkedIndex++) {
        final long currentId = mCheckedIdStates.keyAt(checkedIndex);
        final int currentPosition = mCheckedIdStates.valueAt(checkedIndex);

        final long newPositionId = adapter.getItemId(currentPosition);
        if (currentId != newPositionId) {
            // Look around to see if the ID is nearby. If not, uncheck it.
            final int start = Math.max(0, currentPosition - CHECK_POSITION_SEARCH_DISTANCE);
            final int end = Math.min(currentPosition + CHECK_POSITION_SEARCH_DISTANCE, itemCount);

            boolean found = false;
            for (int searchPos = start; searchPos < end; searchPos++) {
                final long searchId = adapter.getItemId(searchPos);
                if (currentId == searchId) {
                    found = true;
                    mCheckedStates.put(searchPos, true);
                    mCheckedIdStates.setValueAt(checkedIndex, searchPos);
                    break;
                }
            }

            if (!found) {
                mCheckedIdStates.delete(currentId);
                mCheckedCount--;
                checkedIndex--;
            }
        } else {
            mCheckedStates.put(currentPosition, true);
        }
    }
}
 

import android.support.v7.widget.RecyclerView.Adapter; //导入方法依赖的package包/类
public boolean isFooter(int position) {
    Adapter adapter = mList.getAdapter();
    return adapter != null && position >= adapter.getItemCount() - mFooters;
}