Question

我有一个listview并使用arrayadpter创建它但是当我尝试添加数据时，它显示空行，每次我试图清空数据，香港专业教育学院检查数据库，输入的信息只是从未显示在行上。代码如下：

public class Column_Adapter extends ArrayAdapter<Income>{


    public LayoutInflater inflater;
    public ArrayList<Income> incomes;
    public int viewResource;

    public Column_Adapter(Context context, int textViewResourceId, ArrayList<Income> incomes){
        super(context, textViewResourceId, incomes);
        this.incomes = incomes;
        inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        viewResource = textViewResourceId;
    }

    public View getView(int position, View convertView, ViewGroup parent){
        convertView = inflater.inflate(viewResource, null);

        Income income = incomes.get(position);



        if(income !=null) {
            TextView infoView = (TextView) convertView.findViewById(R.id.expense_type);
            TextView amountView = (TextView) convertView.findViewById(R.id.expense_amount);
            TextView budgetView = (TextView) convertView.findViewById(R.id.expense_budget);
            if (infoView != null) {
                infoView.setText(income.getiDate());
            }if(amountView != null){
                amountView.setText(income.getiAmount());
            }if(budgetView != null){
                budgetView.setText(income.getiMethod());
            }
        }

        return convertView;
    }
}

布局模板：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/expense_budget"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/eExpInc"
        android:layout_marginLeft="32dp"
        android:layout_marginStart="32dp"
        android:layout_alignBaseline="@+id/expense_amount"
        android:layout_alignBottom="@+id/expense_amount"
        android:textAppearance="@style/TextAppearance.AppCompat.Large"
        android:textSize="18sp"
        android:textStyle="bold"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />

    <TextView
        android:id="@+id/expense_type"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/eDefaultType"
        android:layout_marginRight="52dp"
        android:layout_marginEnd="52dp"
        android:layout_alignBaseline="@+id/expense_amount"
        android:layout_alignBottom="@+id/expense_amount"
        android:layout_alignParentRight="true"
        android:layout_alignParentEnd="true"
        android:textAppearance="@style/TextAppearance.AppCompat.Large"
        android:textSize="18sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/expense_amount"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="51dp"
        android:text="@string/eDefaultAmount"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:textAppearance="@style/TextAppearance.AppCompat.Large"
        android:textSize="18sp"
        android:textStyle="bold" />



</RelativeLayout>

Answer 1

似乎你忘记了这个

public int getCount() {
    if(incomes!=null)
    return incomes.size();
    return 0;
}

Answer 2

以下链接包含的代码可以帮助您

http://www.mediafire.com/file/wy6pv7664jp5m8m/CustomListviewAdapterExam.7z

这将在listadapter类和一个活动

上有setter和getter类

SQLite Listview返回空行数据

2 个答案: