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我正在使用循環來讀取列表視圖中的所有旋轉元素(在cardview中)。閱讀列表視圖中的所有值Android
但是循環只給出一個項目,即最後一個項目。
我已經包含了所有的源代碼。
可能是什麼問題?
是否有任何其他方式來閱讀所有列表中的項目?
主要佈局
<?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:id="@+id/activity_main"
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">
<LinearLayout android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:id="@+id/ll_gpa"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true">
<ListView
android:id="@+id/listSubs"
android:scrollbars="none"
android:layout_height="0dip"
android:layout_width="match_parent"
android:layout_weight="1"
/>
<Button
android:text="Calculate GPA"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/btnGpa"
android:textAlignment="center"
android:layout_gravity="center_horizontal" />
</LinearLayout>
</RelativeLayout>
單項佈局
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/cv_subject"
android:layout_marginBottom="2dp"
android:layout_marginTop="2dp"
>
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:padding="15dp"
android:id="@+id/rl_subject"
>
<TextView
android:id="@+id/subTitle"
android:textSize="16sp"
android:text="Subject"
android:layout_toStartOf="@+id/subGrade"
android:layout_toLeftOf="@+id/subGrade"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:ellipsize="none"
/>
<Spinner
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:spinnerMode="dropdown"
android:dropDownWidth="40dp"
android:textAlignment="center"
android:entries="@array/grades"
android:id="@+id/subGrade"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
/>
</RelativeLayout>
</android.support.v7.widget.CardView>
MainActivity
public class MainActivity extends AppCompatActivity {
private static SubjectArrayAdapter adapter;
private ProgressDialog progress;
JsonArray subs = new JsonArray();
JsonArray dataGrades = new JsonArray();
ListView listView;
ArrayList<SubjectClass> subjects = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
res = new GetSubNames().execute();
subs = res.getAsJsonArray("subjects");
for (int i = 0; i < subs.size(); i++){
JsonObject temp = subs.get(i).getAsJsonObject();
subjects.add(new SubjectClass(temp.get("subCode").getAsString(), temp.get("subTitle").getAsString()));
}
adapter = new SubjectArrayAdapter(subjects,GpaActivity.this);
listView.setAdapter(adapter);
adapter.notifyDataSetChanged();
Button btnGpa = (Button) findViewById(R.id.btnGpa);
btnGpa.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new CalcGPA().execute();
JsonArray temparr = new JsonArray();
for (int i = 0; i < listView.getChildCount(); i++) {
// Get row's spinner
View listItem = listView.getChildAt(i);
JsonObject temp = new JsonObject();
Spinner spinner = (Spinner) listItem.findViewById(R.id.subGrade);
temp.addProperty("subject",subjects.get(i).getCode());
temp.addProperty("grade", spinner.getSelectedItem().toString());
temparr.add(temp);
}
dataGrades = temparr;
}
});
}
}
自定義類
class SubjectClass{
String title;
String code;
SubjectClass(String code, String title) {
this.code = code;
this.title = title;
}
String getTitle(){
return this.title;
}
String getCode(){
return this.code;
}
void setCode(String code){
this.code = code;
}
void setTitle(String title){
this.title = title;
}
}
定製ArrayAdapter
public class SubjectArrayAdapter extends ArrayAdapter<SubjectClass>{
private ArrayList<SubjectClass> dataSet;
Context mContext;
// View lookup cache
private static class ViewHolder {
TextView txtName;
}
public SubjectArrayAdapter(ArrayList<SubjectClass> data, Context context) {
super(context, R.layout.item_subject, data);
this.dataSet = data;
this.mContext=context;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// Get the data item for this position
SubjectClass dataModel = getItem(position);
// Check if an existing view is being reused, otherwise inflate the view
ViewHolder viewHolder; // view lookup cache stored in tag
final View result;
if (convertView == null) {
viewHolder = new ViewHolder();
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(R.layout.item_subject, parent, false);
viewHolder.txtName = (TextView) convertView.findViewById(R.id.subTitle);
result = convertView;
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
result = convertView;
}
viewHolder.txtName.setText(dataModel.getCode() + " " + dataModel.getTitle());
// Return the completed view to render on screen
return convertView;
}
}
不工作。無法將SubjectClass轉換爲View,會出現錯誤。 –