我有一个活动，它显示从 ArrayList 获取的最初填充的自定义 ListView，然后用户可以添加到这个列表中，我可以毫无问题地存储它。我在显示添加的项目时遇到问题。到目前为止，我在网上看到的代码使用 ArrayAdapter 并且它们只使用简单的 listView 而不是自定义的。
以下是相关文件：
list_row_layout.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="@+id/variant"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="variant" />
<TextView
android:id="@+id/quantity"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="quantity" />
<TextView
android:id="@+id/unit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_marginRight="221dp"
android:layout_toLeftOf="@+id/quantity"
android:text="unit" />
</RelativeLayout>
这是我的 activity_order_form.xml 中具有 listView 元素的部分。
<RelativeLayout
android:id="@+id/relativeLayout3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_below="@+id/relativeLayout2"
android:orientation="vertical" >
<TextView
android:id="@+id/textViewVariantB"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="94dp"
android:text="Variant"
android:textAppearance="?android:attr/textAppearanceLarge" />
<TextView
android:id="@+id/textViewUnit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:layout_marginRight="123dp"
android:text="Unit"
android:textAppearance="?android:attr/textAppearanceLarge" />
<ListView
android:id="@+id/listViewProductOrder"
android:layout_width="match_parent"
android:layout_height="350dp"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_below="@+id/textViewVariantB" >
</ListView>
</RelativeLayout>
这是存储 ArrayList 的类。
public class CurrentOrderClass {
private String productName;
//ArrayLists
private ArrayList<String> variantArray = new ArrayList<String>();
private ArrayList<String> unitArray = new ArrayList<String>();
private ArrayList<Integer> quantityArray = new ArrayList<Integer>();
//TODO ArrayList functions
public ArrayList<String> getUnitArray() {
return unitArray;
}
public void setUnitArray(ArrayList<String> unitArray) {
this.unitArray = unitArray;
}
public void addToUnitArray(String unit){
this.unitArray.add(unit);
}
public ArrayList<Integer> getQuantityArray() {
return quantityArray;
}
public void setQuantityArray(ArrayList<Integer> quantityArray) {
this.quantityArray = quantityArray;
}
public void addToQuantityArray(int quantity){
this.quantityArray.add(quantity);
}
public ArrayList<String> getVariantArray() {
return variantArray;
}
public void setVariantArray(ArrayList<String> variantArray) {
this.variantArray = variantArray;
}
public void addToVariantArray(String variantArray){
this.variantArray.add(variantArray);
}
}
这是 CustomListAdapter.java 文件
public class CustomListAdapter extends BaseAdapter {
private ArrayList<CurrentOrderClass> listData;
private LayoutInflater layoutInflater;
public CustomListAdapter(Context context, ArrayList<CurrentOrderClass> listData) {
this.listData = listData;
layoutInflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
return listData.size();
}
@Override
public Object getItem(int position) {
return listData.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = layoutInflater.inflate(R.layout.list_row_layout, null);
holder = new ViewHolder();
holder.variantView = (TextView) convertView.findViewById(R.id.variant);
holder.unitView = (TextView) convertView.findViewById(R.id.unit);
holder.quantityView = (TextView) convertView.findViewById(R.id.quantity);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.variantView.setText(listData.get(position).getVariantArray().get(position).toString());
holder.unitView.setText(listData.get(position).getUnitArray().get(position).toString());
holder.quantityView.setText(String.valueOf(listData.get(position).getQuantityRow()));
return convertView;
}
static class ViewHolder {
TextView variantView;
TextView unitView;
TextView quantityView;
}
}
这是我的 OrderForm.java 活动的一部分，它显示了 onCreate 和填充 listView 的方法，以及获取用户输入的部分。
public class OrderForm extends Activity {
public TextView tv;
private int variantPosition;
CustomListAdapter customListAdapter;
CurrentOrderClass currentOrder = new CurrentOrderClass();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_order_form);
tv = (TextView)findViewById(R.id.textViewProduct);
//set variants here
popolateItem();
//set current order listview here
ArrayList image_details = getListData();
final ListView lv1 = (ListView) findViewById(R.id.listViewProductOrder);
customListAdapter = new CustomListAdapter(this, image_details);
lv1.setAdapter(customListAdapter);
}
private ArrayList getListData() {
ArrayList results = new ArrayList();
for(int i = 0; i < 10; i++){
currentOrder.getQuantityArray().add(i);
currentOrder.getUnitArray().add("Sample text here." + i);
currentOrder.getVariantArray().add("Another sample text here" + i);
results.add(currentOrder);
}
return results;
}
//....snip snip excess code.....
//This is the part wherein I add new items to the ArrayList in the class
//After this, I'm not sure how to proceed
currentOrder.setProductName(product.getName());
currentOrder.addToQuantityArray(newQuantity);
currentOrder.addToUnitArray(product.getUnit()[position]);
currentOrder.addToVariantArray(product.getVariant()[variantPosition]);
Log.d("Angelo", currentOrder.getProductName() + " "
+ currentOrder.getQuantityArray() + " "
+ currentOrder.getUnitArray() + " "
+ currentOrder.getVariantArray());
}
我也尝试customListAdapter.notifyDataSetChanged();在日志条目之后放置，但什么也没发生。有什么想法吗？谢谢。
回答和修改后编辑。
只需按照下面 FD 的回答并添加他在那里指定的函数以及之后的 2 个函数调用。现在，你想像这样修改你的getListData()函数：
private ArrayList getListData() {
ArrayList results = new ArrayList();
int loopUntil;
/* Two scenarios
* First ---> the user started the activity for the first time, which means that the pre-populated list is what we want
* if this is the case, look at the else part of the boolean statement, it only loops until 10
* and in addition, populates those elements
* Second ---> the user has set something already and we want to populate until that element.
*
*/
if(currentOrder.getQuantityArray().size() > 10){
loopUntil = currentOrder.getQuantityArray().size();
for(int i = 0; i < loopUntil; i++){
currentOrder.getQuantityArray();
currentOrder.getUnitArray();
currentOrder.getVariantArray();
results.add(currentOrder);
}
}
else{
loopUntil = 10;
for(int i = 0; i < loopUntil; i++){
currentOrder.getQuantityArray().add(i);
currentOrder.getUnitArray().add("Sample text here." + i);
currentOrder.getVariantArray().add("Another sample text here" + i);
results.add(currentOrder);
}
}
return results;
}
第一个条件在有一个超出预填充的项目时执行，因为 else 语句只循环到预填充的项目（项目编号 9，索引 0）。此循环确保您添加到 ArrayList 的所有内容都添加到 ListView。
第二个条件在第一次打开活动时执行，并且该列表中应该没有任何内容，除了您自己填充的那些。