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Agregar un encabezado a un GridView(Android) (10)

Soy consciente de que GridView NO es compatible con un encabezado o pie de página. Estoy usando extensamente GridViews y me gustaría tener encabezados que se desplacen con él.

¿Cuál es la mejor manera de abordar el problema? ¿Extender GridView? ¿Extender ScrollView o ListView?

Cualquier puntero o sugerencia sería muy apreciada! ¡Gracias!


Creo que esto es posible haciendo tu propio diseño:

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

Para agregar un encabezado, use algo como eso:

container.addView(header, 0);

y por último debes expandir la altura de GridView:

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



Encontré otra biblioteca que permite tener encabezados en un gridView.

No me molesta importarlo y tiene muchos recursos innecesarios, pero funciona bien: AStickyHeader

EDITAR: parece tener una flexibilidad muy molesta con respecto a poner vistas clicables en los encabezados.

Creo que lo mejor es extender desde GridView o implementarlo de una manera diferente (como se muestra here , pero solo admite un solo encabezado, en la parte superior de gridView) o usar un listView con linearLayouts como filas.


Es posible usar HeaderViewListAdapter que es usado internamente por ListView. Tiene las restricciones de que debe tener el mismo número de encabezados que las columnas y que los encabezados no pueden abarcar las columnas (aunque puede jugar con el aspecto para que parezca).

En el lado positivo, es muy fácil envolver su adaptador existente y agregar algunas celdas de encabezado adicionales y no necesita escribir ningún código nuevo.


Me gustaría ampliar GridView en este caso, ya que parece el más fácil. Si decidió ampliar ListView o ScrollView, primero debería implementar todas las funciones de GridView, lo cual es innecesario para su caso.


Mi código en c # se ve así

((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."); } } } }


Puede agregar la vista de encabezado justo encima de su GridView en un archivo de diseño. Me gusta:

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

A continuación, genere la vista de encabezado y agréguela LinearLayout con encabezado de id.

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



Debe agregar vista de encabezado / pie de página antes de llamar a setAdapter (nuevo Your_Adapter) ;

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);


La implementación de Google de HeaderGridView resuelve este problema. Están subclasificando GridView.

HeaderGridView

Creo que esto es parte de la aplicación Google+ Fotos o de la aplicación nativa de la Galería.

/* * 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(); } } }