安卓_GridView用法示例

public class GridViewActivity extends AppCompatActivity {
    private  String[] address = {"北京","上海","广州","深圳","苏州","成都","香港","广州","深圳","苏州","成都","香港"};
    GridView mGridView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_grid_view);
        mGridView = findViewById(R.id.gridView);
        mGridView.setAdapter(new MyAdapter());
    }
     class MyAdapter extends BaseAdapter {

        @Override
        public int getCount() {
            return address.length;
        }

        @Override
        public Object getItem(int position) {
            return position;
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View view;
            ViewHolder viewHolder;
            if (convertView == null){
                view = LayoutInflater.from(GridViewActivity.this).inflate(R.layout.grid_item, null);
                viewHolder = new ViewHolder();
                viewHolder.textView = view.findViewById(R.id.textView2);
                view.setTag(viewHolder);
            }else {
                view = convertView;
                viewHolder = (ViewHolder) view.getTag();
            }
            viewHolder.textView.setText(address[position]);
            return view;
        }
    }
    class ViewHolder{
        TextView textView;
    }
}

<?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"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".GridViewActivity">

    <GridView
        android:id="@+id/gridView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:numColumns="3" />
</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="66dp"
        android:layout_marginLeft="66dp"
        android:layout_marginTop="71dp"
        android:text="TextView"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>