头添加到GridView（安卓）(Add a Header to a GridView (Andro

我知道，在GridView不支持页眉或页脚。我大量使用了GridView的，我想有一个与它滚动头。

什么是解决这个问题的最好方法？扩展GridView的？扩展滚动型或ListView？

任何指针或建议将非常感激！谢谢！

Answer 1:

谷歌的执行HeaderGridView解决了这个问题。他们继承GridView的。

HeaderGridView

我相信这是Google+相册应用或展示本机应用程序的任一部分。

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.android.photos.views;
import android.content.Context;
import android.database.DataSetObservable;
import android.database.DataSetObserver;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.FrameLayout;
import android.widget.GridView;
import android.widget.ListAdapter;
import android.widget.WrapperListAdapter;
import java.util.ArrayList;
/**
 * A {@link GridView} that supports adding header rows in a
 * very similar way to {@link ListView}.
 * See {@link HeaderGridView#addHeaderView(View, Object, boolean)}
 */
public class HeaderGridView extends GridView {
    private static final String TAG = "HeaderGridView";
    /**
     * A class that represents a fixed view in a list, for example a header at the top
     * or a footer at the bottom.
     */
    private static class FixedViewInfo {
        /** The view to add to the grid */
        public View view;
        public ViewGroup viewContainer;
        /** The data backing the view. This is returned from {@link ListAdapter#getItem(int)}. */
        public Object data;
        /** <code>true</code> if the fixed view should be selectable in the grid */
        public boolean isSelectable;
    }
    private ArrayList<FixedViewInfo> mHeaderViewInfos = new ArrayList<FixedViewInfo>();
    private void initHeaderGridView() {
        super.setClipChildren(false);
    }
    public HeaderGridView(Context context) {
        super(context);
        initHeaderGridView();
    }
    public HeaderGridView(Context context, AttributeSet attrs) {
        super(context, attrs);
        initHeaderGridView();
    }
    public HeaderGridView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        initHeaderGridView();
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        ListAdapter adapter = getAdapter();
        if (adapter != null && adapter instanceof HeaderViewGridAdapter) {
            ((HeaderViewGridAdapter) adapter).setNumColumns(getNumColumns());
        }
    }
    @Override
    public void setClipChildren(boolean clipChildren) {
       // Ignore, since the header rows depend on not being clipped
    }
    /**
     * Add a fixed view to appear at the top of the grid. If addHeaderView is
     * called more than once, the views will appear in the order they were
     * added. Views added using this call can take focus if they want.
     * <p>
     * NOTE: Call this before calling setAdapter. This is so HeaderGridView can wrap
     * the supplied cursor with one that will also account for header views.
     *
     * @param v The view to add.
     * @param data Data to associate with this view
     * @param isSelectable whether the item is selectable
     */
    public void addHeaderView(View v, Object data, boolean isSelectable) {
        ListAdapter adapter = getAdapter();
        if (adapter != null && ! (adapter instanceof HeaderViewGridAdapter)) {
            throw new IllegalStateException(
                    "Cannot add header view to grid -- setAdapter has already been called.");
        }
        FixedViewInfo info = new FixedViewInfo();
        FrameLayout fl = new FullWidthFixedViewLayout(getContext());
        fl.addView(v);
        info.view = v;
        info.viewContainer = fl;
        info.data = data;
        info.isSelectable = isSelectable;
        mHeaderViewInfos.add(info);
        // in the case of re-adding a header view, or adding one later on,
        // we need to notify the observer
        if (adapter != null) {
            ((HeaderViewGridAdapter) adapter).notifyDataSetChanged();
        }
    }
    /**
     * Add a fixed view to appear at the top of the grid. If addHeaderView is
     * called more than once, the views will appear in the order they were
     * added. Views added using this call can take focus if they want.
     * <p>
     * NOTE: Call this before calling setAdapter. This is so HeaderGridView can wrap
     * the supplied cursor with one that will also account for header views.
     *
     * @param v The view to add.
     */
    public void addHeaderView(View v) {
        addHeaderView(v, null, true);
    }
    public int getHeaderViewCount() {
        return mHeaderViewInfos.size();
    }
    /**
     * Removes a previously-added header view.
     *
     * @param v The view to remove
     * @return true if the view was removed, false if the view was not a header
     *         view
     */
    public boolean removeHeaderView(View v) {
        if (mHeaderViewInfos.size() > 0) {
            boolean result = false;
            ListAdapter adapter = getAdapter();
            if (adapter != null && ((HeaderViewGridAdapter) adapter).removeHeader(v)) {
                result = true;
            }
            removeFixedViewInfo(v, mHeaderViewInfos);
            return result;
        }
        return false;
    }
    private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) {
        int len = where.size();
        for (int i = 0; i < len; ++i) {
            FixedViewInfo info = where.get(i);
            if (info.view == v) {
                where.remove(i);
                break;
            }
        }
    }
    @Override
    public void setAdapter(ListAdapter adapter) {
        if (mHeaderViewInfos.size() > 0) {
            HeaderViewGridAdapter hadapter = new HeaderViewGridAdapter(mHeaderViewInfos, adapter);
            int numColumns = getNumColumns();
            if (numColumns > 1) {
                hadapter.setNumColumns(numColumns);
            }
            super.setAdapter(hadapter);
        } else {
            super.setAdapter(adapter);
        }
    }
    private class FullWidthFixedViewLayout extends FrameLayout {
        public FullWidthFixedViewLayout(Context context) {
            super(context);
        }
        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            int targetWidth = HeaderGridView.this.getMeasuredWidth()
                    - HeaderGridView.this.getPaddingLeft()
                    - HeaderGridView.this.getPaddingRight();
            widthMeasureSpec = MeasureSpec.makeMeasureSpec(targetWidth,
                    MeasureSpec.getMode(widthMeasureSpec));
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        }
    }
    /**
     * ListAdapter used when a HeaderGridView has header views. This ListAdapter
     * wraps another one and also keeps track of the header views and their
     * associated data objects.
     *<p>This is intended as a base class; you will probably not need to
     * use this class directly in your own code.
     */
    private static class HeaderViewGridAdapter implements WrapperListAdapter, Filterable {
        // This is used to notify the container of updates relating to number of columns
        // or headers changing, which changes the number of placeholders needed
        private final DataSetObservable mDataSetObservable = new DataSetObservable();
        private final ListAdapter mAdapter;
        private int mNumColumns = 1;
        // This ArrayList is assumed to NOT be null.
        ArrayList<FixedViewInfo> mHeaderViewInfos;
        boolean mAreAllFixedViewsSelectable;
        private final boolean mIsFilterable;
        public HeaderViewGridAdapter(ArrayList<FixedViewInfo> headerViewInfos, ListAdapter adapter) {
            mAdapter = adapter;
            mIsFilterable = adapter instanceof Filterable;
            if (headerViewInfos == null) {
                throw new IllegalArgumentException("headerViewInfos cannot be null");
            }
            mHeaderViewInfos = headerViewInfos;
            mAreAllFixedViewsSelectable = areAllListInfosSelectable(mHeaderViewInfos);
        }
        public int getHeadersCount() {
            return mHeaderViewInfos.size();
        }
        @Override
        public boolean isEmpty() {
            return (mAdapter == null || mAdapter.isEmpty()) && getHeadersCount() == 0;
        }
        public void setNumColumns(int numColumns) {
            if (numColumns < 1) {
                throw new IllegalArgumentException("Number of columns must be 1 or more");
            }
            if (mNumColumns != numColumns) {
                mNumColumns = numColumns;
                notifyDataSetChanged();
            }
        }
        private boolean areAllListInfosSelectable(ArrayList<FixedViewInfo> infos) {
            if (infos != null) {
                for (FixedViewInfo info : infos) {
                    if (!info.isSelectable) {
                        return false;
                    }
                }
            }
            return true;
        }
        public boolean removeHeader(View v) {
            for (int i = 0; i < mHeaderViewInfos.size(); i++) {
                FixedViewInfo info = mHeaderViewInfos.get(i);
                if (info.view == v) {
                    mHeaderViewInfos.remove(i);
                    mAreAllFixedViewsSelectable = areAllListInfosSelectable(mHeaderViewInfos);
                    mDataSetObservable.notifyChanged();
                    return true;
                }
            }
            return false;
        }
        @Override
        public int getCount() {
            if (mAdapter != null) {
                return getHeadersCount() * mNumColumns + mAdapter.getCount();
            } else {
                return getHeadersCount() * mNumColumns;
            }
        }
        @Override
        public boolean areAllItemsEnabled() {
            if (mAdapter != null) {
                return mAreAllFixedViewsSelectable && mAdapter.areAllItemsEnabled();
            } else {
                return true;
            }
        }
        @Override
        public boolean isEnabled(int position) {
            // Header (negative positions will throw an ArrayIndexOutOfBoundsException)
            int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
            if (position < numHeadersAndPlaceholders) {
                return (position % mNumColumns == 0)
                        && mHeaderViewInfos.get(position / mNumColumns).isSelectable;
            }
            // Adapter
            final int adjPosition = position - numHeadersAndPlaceholders;
            int adapterCount = 0;
            if (mAdapter != null) {
                adapterCount = mAdapter.getCount();
                if (adjPosition < adapterCount) {
                    return mAdapter.isEnabled(adjPosition);
                }
            }
            throw new ArrayIndexOutOfBoundsException(position);
        }
        @Override
        public Object getItem(int position) {
            // Header (negative positions will throw an ArrayIndexOutOfBoundsException)
            int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
            if (position < numHeadersAndPlaceholders) {
                if (position % mNumColumns == 0) {
                    return mHeaderViewInfos.get(position / mNumColumns).data;
                }
                return null;
            }
            // Adapter
            final int adjPosition = position - numHeadersAndPlaceholders;
            int adapterCount = 0;
            if (mAdapter != null) {
                adapterCount = mAdapter.getCount();
                if (adjPosition < adapterCount) {
                    return mAdapter.getItem(adjPosition);
                }
            }
            throw new ArrayIndexOutOfBoundsException(position);
        }
        @Override
        public long getItemId(int position) {
            int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
            if (mAdapter != null && position >= numHeadersAndPlaceholders) {
                int adjPosition = position - numHeadersAndPlaceholders;
                int adapterCount = mAdapter.getCount();
                if (adjPosition < adapterCount) {
                    return mAdapter.getItemId(adjPosition);
                }
            }
            return -1;
        }
        @Override
        public boolean hasStableIds() {
            if (mAdapter != null) {
                return mAdapter.hasStableIds();
            }
            return false;
        }
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // Header (negative positions will throw an ArrayIndexOutOfBoundsException)
            int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns ;
            if (position < numHeadersAndPlaceholders) {
                View headerViewContainer = mHeaderViewInfos
                        .get(position / mNumColumns).viewContainer;
                if (position % mNumColumns == 0) {
                    return headerViewContainer;
                } else {
                    if (convertView == null) {
                        convertView = new View(parent.getContext());
                    }
                    // We need to do this because GridView uses the height of the last item
                    // in a row to determine the height for the entire row.
                    convertView.setVisibility(View.INVISIBLE);
                    convertView.setMinimumHeight(headerViewContainer.getHeight());
                    return convertView;
                }
            }
            // Adapter
            final int adjPosition = position - numHeadersAndPlaceholders;
            int adapterCount = 0;
            if (mAdapter != null) {
                adapterCount = mAdapter.getCount();
                if (adjPosition < adapterCount) {
                    return mAdapter.getView(adjPosition, convertView, parent);
                }
            }
            throw new ArrayIndexOutOfBoundsException(position);
        }
        @Override
        public int getItemViewType(int position) {
            int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
            if (position < numHeadersAndPlaceholders && (position % mNumColumns != 0)) {
                // Placeholders get the last view type number
                return mAdapter != null ? mAdapter.getViewTypeCount() : 1;
            }
            if (mAdapter != null && position >= numHeadersAndPlaceholders) {
                int adjPosition = position - numHeadersAndPlaceholders;
                int adapterCount = mAdapter.getCount();
                if (adjPosition < adapterCount) {
                    return mAdapter.getItemViewType(adjPosition);
                }
            }
            return AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER;
        }
        @Override
        public int getViewTypeCount() {
            if (mAdapter != null) {
                return mAdapter.getViewTypeCount() + 1;
            }
            return 2;
        }
        @Override
        public void registerDataSetObserver(DataSetObserver observer) {
            mDataSetObservable.registerObserver(observer);
            if (mAdapter != null) {
                mAdapter.registerDataSetObserver(observer);
            }
        }
        @Override
        public void unregisterDataSetObserver(DataSetObserver observer) {
            mDataSetObservable.unregisterObserver(observer);
            if (mAdapter != null) {
                mAdapter.unregisterDataSetObserver(observer);
            }
        }
        @Override
        public Filter getFilter() {
            if (mIsFilterable) {
                return ((Filterable) mAdapter).getFilter();
            }
            return null;
        }
        @Override
        public ListAdapter getWrappedAdapter() {
            return mAdapter;
        }
        public void notifyDataSetChanged() {
            mDataSetObservable.notifyChanged();
        }
    }
}

Answer 2:

我用Stickygridheaders从GitHub，这是非常漂亮和简单的，试试吧。

Answer 3:

我会去，因为它似乎最容易在这种情况下扩展GridView控件。如果您决定延长的ListView或滚动型你就必须首先实现所有的GridView的功能，这是不必要的你的情况。

Answer 4:

实现它自己之后，我可以说，最简单的方法是使处理列的适配器，并使用一个ListView与默认标题

我在这里发表一个示例代码： https://github.com/plattysoft/grid-with-header-list-adapter/

Answer 5:

你必须调用 setAdapter（新Your_Adapter） 之前添加页眉/页脚视图。

  Try below code:



  LayoutInflater layoutInflater = LayoutInflater.from(getActivity());
  View footerView = layoutInflater.inflate(R.layout.grid_view_footer, null);
  myListViewOrGridView.addFooterView(footerView);
  YourAdapter mAdapter = new YourAdapter(getActivity(), Your_Argument_Here);
  myListViewOrGridView.setAdapter(mAdapter);

Answer 6:

您可以添加右一个布局文件你的GridView上面的标题视图。喜欢：

<LinearLayout>
...
    <LinearLayout
        android:id="@+id/header" />
    <com.sample.MyGridView />
...
</LinearLayout>

然后生成报头图和ID为标头添加它的LinearLayout

View header = inflater.inflate(R.layout.head_view, null);
LinearLayout headerContainer = (LinearLayout) findViewById(R.id.header);
headerContainer.addView(header);

Answer 7:

它可以使用由ListView控件内部使用的HeaderViewListAdapter。它，你必须有相同数量的标头，列和头不能跨越的列（虽然你可以用一下，使他们看起来玩）的限制。

在加方很容易将保鲜膜现有的适配器，并添加一些额外的头细胞和你不需要编写任何新的代码。

Answer 8:

我发现另一个库，允许其在GridView的头。

I'T有点恼人导入，然后它有许多非所需的资源，但它工作正常： AStickyHeader

编辑：它似乎有关于戴上头可点击的意见很烦人的灵活性。

我认为最好是从GridView的延长或以不同的方式实现它（如图所示这里，但它仅支持一个头，在GridView上的顶部），或者使用一个ListView与linearLayouts为行。

Answer 9:

我在C＃代码如下所示

((HeaderViewGridAdapter)Adapter).NumColumns = NumColumnsCompatible;

private int NumColumnsCompatible
    {
        get
        {
            if (Build.VERSION.SdkInt >= BuildVersionCodes.Honeycomb)
            {
                return base.NumColumns;
            }
            else
            {
                try
                {
                    Field numColumns = this.Class.GetDeclaredField("numColumns");
                    numColumns.Accessible = true;

                    return numColumns.GetInt(this);
                }
                catch (Exception e)
                {
                    if (numColumns != -1)
                    {
                        return numColumns;
                    }
                    throw new Exception("Can not determine the NumColumns for this API platform, please call setNumColumns to set it.");
                }
            }
        }
    }

Answer 10:

我认为这是可能通过使自己的布局：

<ScrollView>
  <LinearLayout android:id="@+id/container">
    <com.project.MyGridView/>
  </LinearLayout>
</ScrollView>

要添加页眉使用类似的东西：

container.addView(header, 0);

和最后你必须扩大GridView的高度：

Class MyGridView extends GridView {
    ....
    @Override
    protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, MeasureSpec.UNSPECIFIED);
    }
    ....
}