Android开发-ListView, GridView,Scrollview

ListView

• 常用属性
• Adapter接口
• Demo演示

listview效果图

activity_listview.xml

ListViewActivity

public class ListViewActivity extends Activity {

    private ListView mLv1;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_listview);
        mLv1 = findViewById(R.id.lv_1);
        mLv1.setAdapter(new MyListAdapter(ListViewActivity.this));
        mLv1.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView parent, View view, int position, long id) {
                Toast.makeText(ListViewActivity.this, "点击 Pos:" + position, Toast.LENGTH_SHORT).show();
                // 跳转
            }
        });

        mLv1.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView parent, View view, int position, long id) {
                Toast.makeText(ListViewActivity.this, "长按 Pos:" + position, Toast.LENGTH_SHORT).show();
                return false;
            }
        });
    }
}

MyListAdapter

public class MyListAdapter extends BaseAdapter {

    private Context mContext;
    private LayoutInflater mLayoutInflater;

    public MyListAdapter(Context context) {
        mContext = context;
        mLayoutInflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return 10;
    }

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

    @Override
    public long getItemId(int position) {
        return 0;
    }

    static class ViewHolder {

        public ImageView imageView;
        public TextView tvTitle, tvTime, tvContent;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        ViewHolder holder = null;
        if (convertView == null) {
            convertView = mLayoutInflater.inflate(R.layout.layout_list_item, null);
            holder = new ViewHolder();
            holder.imageView = convertView.findViewById(R.id.iv);
            holder.tvTitle = convertView.findViewById(R.id.tv_title);
            holder.tvTime = convertView.findViewById(R.id.tv_time);
            holder.tvContent = convertView.findViewById(R.id.tv_content);
            convertView.setTag(holder);
        } else  {
            holder = (ViewHolder) convertView.getTag();
        }
        holder.tvTitle.setText("这是标题");
        holder.tvTime.setText("2099-09-09");
        holder.tvContent.setText("这是内容");
        Glide.with(mContext).load("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1603459341312&di=bc520d0ed58b8e3786e74ef3f8442985&imgtype=0&src=http%3A%2F%2Fz1.dfcfw.com%2F2020%2F10%2F14%2F20201014075848343834694.jpg").into(holder.imageView);
        return convertView;
    }
}

GridView

• 常用属性
• Adapter接口
• Demo演示

效果图

gridview 效果图

activity_gridview.xml

layout_grid_item.xml

GridViewActivity

public class GridViewActivity extends AppCompatActivity {

    private GridView mGv;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_gridview);
        mGv = findViewById(R.id.gv);
        mGv.setAdapter(new MyGridViewAdapter(GridViewActivity.this));
        mGv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView parent, View view, int position, long id) {
                Toast.makeText(GridViewActivity.this, "点击：" + position, Toast.LENGTH_SHORT).show();
            }
        });
        mGv.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView parent, View view, int position, long id) {
                Toast.makeText(GridViewActivity.this, "长按：" + position, Toast.LENGTH_SHORT).show();
                return true;
            }
        });
    }
}

MyGidViewAdapter

public class MyGridViewAdapter extends BaseAdapter {

    private Context mContext;
    private LayoutInflater mLayoutInflater;

    public MyGridViewAdapter(Context context) {
        mContext = context;
        mLayoutInflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return 10;
    }

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

    @Override
    public long getItemId(int position) {
        return 0;
    }

    static class ViewHolder {
        public ImageView imageView;
        public TextView tvTitle;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder = null;
        if (convertView == null) {
            convertView = mLayoutInflater.inflate(R.layout.layout_grid_item, null);
            holder = new ViewHolder();
            holder.imageView = convertView.findViewById(R.id.iv_grid);
            holder.tvTitle = convertView.findViewById(R.id.tv_title);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.tvTitle.setText("花");
        Glide.with(mContext).load("https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1603459341312&di=bc520d0ed58b8e3786e74ef3f8442985&imgtype=0&src=http%3A%2F%2Fz1.dfcfw.com%2F2020%2F10%2F14%2F20201014075848343834694.jpg").into(holder.imageView);
        return convertView;
    }
}

ScrollView

• 垂直滚动 ScrollView
• 水平滚动 HorizontalScrollView

scrollview效果图