我已经看到了许多关于如何实现与网格的其余部分一起滚动的 gridview 标题的解决方案。
它们中的大多数包括在滚动视图中创建一个带有标题视图和网格视图的列表布局或相对布局。此解决方案存在滚动视图不知道网格大小的问题，因此要克服您需要像这里一样扩展网格视图：https ://stackoverflow.com/a/4536955/751180
但问题是，这样做会迫使 gridview 一次渲染所有项目而不回收其单元格。这可能会导致应用程序由于大量内存使用而崩溃，特别是如果视图包含图像。
其他人正在使用 Listviews 并根据屏幕大小计算可以放置多少列。我个人想继续使用网格视图。
有没有人使用不同的方法实现过 gridview 标头？
我花了很多时间尝试为 GridView 设置正确的标题。没有成功。看来，实现自定义 GridView（继承自 ListView）是唯一合理的方法。这是带有页眉和页脚的此类 GridView 的示例：https ://github.com/SergeyBurish/HFGridView
您可以尝试使用以下库https://github.com/maurycyw/HeaderGridView 可能会有所帮助。
我使用来自 sdcard 位置源的图像标题进行了自定义网格视图。我的整个项目都放在下面。如果它对任何人都有帮助，请投票给我以提高声誉。
public class MainActivity extends Activity {
private File file;
LinearLayout linear;
ArrayList<Bitmap> listbitmap;
String[] folderlist ;
ExpandableHeightGridView gridview;
LinearLayout linearhere;
String imageInSD = Environment.getExternalStorageDirectory().getAbsolutePath() +"/Hi";
ArrayList<String> mylist = new ArrayList<String>();
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
linear = (LinearLayout) findViewById(R.id.linear);
File imagesSource = new File(imageInSD);
File[] dictoryFiles = imagesSource.listFiles();
for(int i =0; i<dictoryFiles.length;i++){
mylist.add(dictoryFiles[i].getName());
}
folderlist = mylist.toArray(new String[mylist.size()]);
linearhere = new LinearLayout(getApplicationContext());
linearhere.setOrientation(LinearLayout.VERTICAL);
for (int k = 0; k < folderlist.length; k++) {
TextView textview = new TextView(getApplicationContext());
textview.setTextColor(Color.BLACK);
textview.setTextSize(20);
textview.setText(folderlist[k]);
gridview = new ExpandableHeightGridView(getApplicationContext());
gridview.setId(Calendar.SECOND);
gridview.setLayoutParams(new GridView.LayoutParams(LayoutParams.FILL_PARENT,LayoutParams.FILL_PARENT));
gridview.setBackgroundColor(Color.WHITE);
gridview.setNumColumns(3);
gridview.setColumnWidth(GridView.AUTO_FIT);
gridview.setVerticalSpacing(5);
gridview.setHorizontalSpacing(5);
gridview.setStretchMode(GridView.STRETCH_COLUMN_WIDTH);
listbitmap = new ArrayList<Bitmap>();
file = new File(imageInSD + "/" + folderlist[k]);
File list[] = file.listFiles();
for (int i = 0; i < list.length; i++) {
String sp=list[i].getName();
//if(sp.startsWith("123")){
//textview.setText(folderlist[k]);
File image = new File(imageInSD + "/"+folderlist[k]+"/" + list[i].getName());
InputStream fis = null;
try {
fis = new FileInputStream(image.getAbsolutePath());
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 2;
Bitmap bm = BitmapFactory.decodeStream(fis, null, options);
listbitmap.add(bm);
//}
}
gridview.setAdapter(new CustomGridAdapter(getApplicationContext(),
listbitmap));
gridview.setExpanded(true);
linearhere.addView(textview);
linearhere.addView(gridview);
}
linear.addView(linearhere);
}
}
======================
class2
======================
public class ExpandableHeightGridView extends GridView
{
boolean expanded = false;
public ExpandableHeightGridView(Context context)
{
super(context);
}
public ExpandableHeightGridView(Context context, AttributeSet attrs)
{
super(context, attrs);
}
public ExpandableHeightGridView(Context context, AttributeSet attrs,
int defStyle)
{
super(context, attrs, defStyle);
}
public boolean isExpanded()
{
return expanded;
}
@Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
// HACK! TAKE THAT ANDROID!
if (isExpanded())
{
// Calculate entire height by providing a very large height hint.
// View.MEASURED_SIZE_MASK represents the largest height possible.
int expandSpec = MeasureSpec.makeMeasureSpec(MEASURED_SIZE_MASK,
MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, expandSpec);
ViewGroup.LayoutParams params = getLayoutParams();
params.height = getMeasuredHeight();
}
else
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
public void setExpanded(boolean expanded)
{
this.expanded = expanded;
}
}
======================
class 3:
======================
public class CustomGridAdapter extends BaseAdapter {
private Context context;
private final ArrayList<Bitmap> gridValues;
// Constructor to initialize values
public CustomGridAdapter(Context context, ArrayList<Bitmap> gridValues) {
this.context = context;
this.gridValues = gridValues;
}
@Override
public int getCount() {
// Number of times getView method call depends upon gridValues.length
return gridValues.size();
}
@Override
public Object getItem(int position) {
return position;
}
@Override
public long getItemId(int id) {
return id;
}
// Number of times getView method call depends upon gridValues.length
public View getView(int position, View convertView, ViewGroup parent) {
// LayoutInflator to call external grid_item.xml file
LayoutInflater inflater = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View gridView;
if (convertView == null) {
gridView = new View(context);
// get layout from grid_item.xml ( Defined Below )
gridView = inflater.inflate(R.layout.grid_item, null);
ImageView imageView = (ImageView) gridView
.findViewById(R.id.grid_item_image);
imageView.setImageBitmap(gridValues.get(position));
} else {
gridView = (View) convertView;
}
return gridView;
}
}
=========================
activity_main.xml Code:
=========================
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:id="@+id/linear"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#D8D8D8"
android:orientation="vertical" >
</LinearLayout>
</ScrollView>
==========================
grid_item.xml code:
==========================
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="5dp" >
<ImageView
android:id="@+id/grid_item_image"
android:layout_width="180dp"
android:layout_margin="5dp"
android:layout_height="150dp"
>
</ImageView>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="0dp" >
</LinearLayout>
</LinearLayout>
我回答得有点晚了，但根据我的经验，这可以通过 RecyclerView api 使用 GridLayoutManager.SpanSizeLookup 帮助器类。例如，您可以在 Activity/Fragment 中执行以下操作。
mRecyclerView = (RecyclerView) view.findViewById(R.id.your_recycler_view);
mLayoutManager = new GridLayoutManager(mContext, 2);
mLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
if (position == 0) {
return 2;
} else {
return 1;
}
}
});
mRecyclerView.setLayoutManager(mLayoutManager);
mAdapter = new RecyclerAdapter();
mRecyclerView.setAdapter(mAdapter);
如果您位于网格的开头（位置 == 0），您的 ViewHolder 将获得最大列跨度，在这种情况下为 2。在您的适配器类中，您需要为标题和项目的视图类型指定常量，并覆盖该int getItemViewType(int position)方法以根据适配器位置返回视图类型。然后RecyclerView.ViewHolder onCreateViewHolder(ViewGroup container, int viewType)根据当前的 viewType inflate 适当的布局。
希望这对未来的读者有所帮助。令人惊讶的是，对于 GridView 标题的类似问题，我还没有看到这个解决方案。