ListView 巢狀 GridView 大法
阿新 • • 發佈:2019-01-05
起因
專案需求要用表格形式實現佈局
但是!!!需要下拉和上拉載入資料。
因為專案裡只有github裡的XListView改造的ListView,又因為本人太笨太懶,不想寫上拉下來gridview。。
廢話不多說
1、定義一個主檢視 listview.xml
<ListView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/listview"
android:layout_width="match_parent"
android:layout_height ="match_parent"
android:clipToPadding="false"
android:divider="@null"
android:dividerHeight="10dp"
android:padding="10dp"></ListView>
就這樣,因為本例講的是listview巢狀gridview,不涉及上拉下拉,所以就用普通的listview咯
2、自定義GridView—NoScrollGridView
其實不自定義也行,當時為了防止gridview顯示補全blabla的,還是寫一個保證萬無一失。
public class NoScrollGridView extends GridView {
public NoScrollGridView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public NoScrollGridView(Context context) {
super(context);
}
public NoScrollGridView(Context context, AttributeSet attrs, int defStyle) {
super (context, attrs, defStyle);
}
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
//核心在此
int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,
MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, expandSpec+50);
}
}
3、定義ListView單項佈局 listview_item.xml
<?xml version="1.0" encoding="utf-8"?>
<com.example.shen.sample.NoScrollGridView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/gridview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:numColumns="2"
android:stretchMode="columnWidth"
android:horizontalSpacing="10dp"
android:verticalSpacing="10dp" />
<!-- 注意
android:numColumns="2"
android:stretchMode="columnWidth"
-->
4、定義GridView單項佈局 gridview_item.xml
<?xml version="1.0" encoding="utf-8"?>
<ImageView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:id="@+id/imageview"
android:background="#000"
android:layout_height="80dp" />
5、定義GridView的資料介面卡 GridViewAdapter.java
/**
* Created by Shen on 2015/10/29.
* 普通的介面卡
*/
public class GridViewAdapter extends BaseAdapter {
//資料來源
private List<MainActivity.Bean> mList = new ArrayList<>();
private Context mContext;
public GridViewAdapter(Context context) {
super();
this.mContext = context;
}
public List<MainActivity.Bean> getmList() {
return mList;
}
public void setmList(List<MainActivity.Bean> mList) {
this.mList = mList;
}
@Override
public int getCount() {
return mList.size();
}
@Override
public MainActivity.Bean getItem(int position) {
return mList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = LayoutInflater.from(mContext).inflate(R.layout.gridview_item, parent, false);
holder = new ViewHolder(convertView);
} else {
holder = (ViewHolder) convertView.getTag();
}
//設定圖片內容,本例木有圖片
// holder.iv.setImageResource(getItem(position));
return convertView;
}
class ViewHolder {
ImageView iv;
public ViewHolder(View view) {
iv = (ImageView) view.findViewById(R.id.imageview);
view.setTag(this);
}
}
}
6、定義ListView的資料介面卡 ListViewAdapter.java
/**
* Created by Shen on 2015/10/29.
* ListView的資料來源
* 在這裡給gridview設定資料
* 重要
*/
public class ListViewAdapter extends BaseAdapter {
//資料來源
private List<MainActivity.Bean> mList = new ArrayList<>();
//列數
private int mColumn = 2;
private Context mContext;
public ListViewAdapter(Context context, List<MainActivity.Bean> list) {
super();
this.mContext = context;
this.mList = list;
}
/**
* 這部很重要
*(核心)
* @return listview的行數
*/
@Override
public int getCount() {
int count = mList.size() / mColumn;
if (mList.size() % mColumn > 0) {
count++;
}
return count;
}
@Override
public MainActivity.Bean getItem(int position) {
return mList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = LayoutInflater.from(mContext).inflate(R.layout.listview_item, parent, false);
holder = new ViewHolder(convertView);
} else {
holder = (ViewHolder) convertView.getTag();
}
//定義gridView的資料來源
List<MainActivity.Bean> list = new ArrayList<>();
//根據列數,將資料塞進去(核心)
for (int i = 0; i < mColumn; i++) {
int n = position * mColumn + i;
if (n < mList.size()) {
list.add(getItem(n));
}
}
//更新資料來源(核心)
holder.adapter.setmList(list);
holder.adapter.notifyDataSetChanged();
return convertView;
}
class ViewHolder {
GridView gridView;
GridViewAdapter adapter;
public ViewHolder(View view) {
gridView = (GridView) view.findViewById(R.id.gridview);
//將adapter定義在此,優化滑動效果(核心)
adapter = new GridViewAdapter(mContext);
//在此設定介面卡,資料來源在getView中新增(核心)
gridView.setAdapter(adapter);
view.setTag(this);
}
}
}
最後MainActivity.java
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listview);
ListView listview = (ListView) findViewById(R.id.listview);
List<Bean> list = new ArrayList();
for (int i = 0; i < 19; i++) {
list.add(new Bean());
}
ListViewAdapter adapter = new ListViewAdapter(this, list);
listview.setAdapter(adapter);
}
public static class Bean {
}
}