android listview 每行的金额 求总和
我用listview 把一些数据通过simpleAdapter 展示出来。 详情如截图
加减 按钮是修改数量。 与此同时，右边的 和 也会随着数量的更改而 更新。
java代码 已经测试过。 目前加减和一切正常。
int cal_quantity;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main8);
List<HashMap<String, String>> aList = new ArrayList<HashMap<String, String>>();
final String name[]={"apple","orange","pear"};
final String quantity[]={"1","2","3"};
final String price[]={"5","10","2"};
for(int i=0;i<name.length;i++){
HashMap<String, String> map = new HashMap<>();
map.put("name",name[i]);
map.put("quantity",quantity[i]);
map.put("price",price[i]);
aList.add(map);
}
String[] from = {"name","quantity","price"};
int[] to = {R.id.name,R.id.quantity,R.id.price};
SimpleAdapter adapter = new SimpleAdapter(this, aList, R.layout.main7, from, to){
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
View v = super.getView(position, convertView, parent);
final TextView tv_quantity=(TextView)v.findViewById(R.id.quantity);
final TextView tv_price=(TextView)v.findViewById(R.id.price);
final TextView tv_total=(TextView)v.findViewById(R.id.total);
final int get_quantity = Integer.parseInt(tv_quantity.getText().toString());
final double get_price= Double.parseDouble(tv_price.getText().toString());
final double get_total=get_quantity*get_price;
tv_total.setText(get_total+"");
Button minus=(Button)v.findViewById(R.id.minus);
minus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
cal_quantity=Integer.parseInt(tv_quantity.getText().toString());
if(cal_quantity!=1){
cal_quantity=cal_quantity-1;
}
tv_quantity.setText(cal_quantity+"");
double get_total=cal_quantity*get_price;
tv_total.setText(get_total+"");
}
});
Button plus=(Button)v.findViewById(R.id.plus);
plus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
cal_quantity=Integer.parseInt(tv_quantity.getText().toString());
cal_quantity=cal_quantity+1;
tv_quantity.setText(cal_quantity+"");
double get_total=cal_quantity*get_price;
tv_total.setText(get_total+"");
}
});
return v;
}
};
ListView listView = (ListView) findViewById(R.id.listview);
listView.setAdapter(adapter);
}
xml - listview和底部的总和 textview分开
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main8"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.yu.singleton.Main8Activity"
android:orientation="vertical">
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_weight="0.3"
android:layout_height="match_parent">
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/listview" />
</LinearLayout>
<LinearLayout
android:orientation="vertical"
android:layout_width="match_parent"
android:background="@android:color/holo_blue_dark"
android:layout_weight="0.7"
android:layout_height="match_parent">
<TextView
android:text="Total"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/textView3"
android:textAlignment="center"
android:textSize="36sp" />
</LinearLayout>
</LinearLayout>
**那么我的问题是如何把每一排最右边的 Textview 值 加起来 ，然后再底部展示出总和？ 我知道大概是用循环，但是实际操作完全没有头绪。
请大神们指点**
