Question

有人知道从spinner获取索引id值，我有这个代码，但它是错误的 Akreditasi.java

public class Akreditasi {
private long id;
private String name;

public long getId() {
    return id;
}
public void setId(long id) {
    this.id = id;
}
public String getName() {
    return nama;
}
public void setName(String name) {
    this.name = name;
}
@Override
public String toString()
{
    return "ID : " + id 
            + "\n" + "Nama :"+ name;
}

}

这是mySpinner 我正在尝试将此Akreditasi传递给ArrayAdapter

public void onItemSelected(AdapterView<?> parent, View view, int position,
        long id) 
                    {
            // TODO Auto-generated method stub
            // On selecting a spinner item
            String label = parent.getItemAtPosition(position).toString();
            Akreditasi mSelected = (Akreditasi) parent.getItemAtPosition(position); //in here my program is crash, it's says cannot be cast 
                    long count = mSelected.getId();

            //set the default according to value
            // Showing selected spinner item
            Toast.makeText(parent.getContext(), "You Selected: " + label,
                    Toast.LENGTH_LONG).show();
}

这是我的微调方法

  private void loadSpinnerData() {
    // TODO Auto-generated method stub
    // database handler
    DBDataSource db = new  DBDataSource(getApplicationContext());
    // Spinner Drop down elements
    List<String> lables = db.getAllLabel_akreditasi();
    // Creating adapter for spinner
    ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,
            android.R.layout.simple_spinner_item, lables);

    // Drop down layout style - list view with radio button
    dataAdapter
            .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    // attaching data adapter to spinner
    spinner.setAdapter(dataAdapter);



}

我仍然不明白这个错误，任何人都可以帮助我吗？谢谢你

Answer 1

因为你没有告诉你将使用哪种微调器，首先，您需要调用onItemSelected方法，如下所示：

(your spinner).setOnItemSelectedListener(this);

在此之后，我建议您在方法switch case上添加onItemSelected，如下所示：

public void onItemSelected(AdapterView<?> parent, View view, int position,
        long id) 
                    {
switch (parent.getId()) {
case R.id.(id of your spinner):


  Akreditasi mSelected = (Akreditasi) parent.getItemAtPosition(position); 
                    long count = mSelected.getId();
break;
}
}

你的微调方法应该是这样的：

 private void loadSpinnerData() {
    DBDataSource db = new  DBDataSource(getApplicationContext());

    List<Akreditasi> lables = db.getAllLabel_akreditasi();

    ArrayAdapter<Akreditasi> dataAdapter = new ArrayAdapter<Akreditasi>(this,
            android.R.layout.simple_spinner_item, lables);

    dataAdapter .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    spinner.setAdapter(dataAdapter);
}

Answer 2

在设置设置时，您只有List<String>但不是List<Akreditasi>

List<String> lables = db.getAllLabel_akreditasi();

你需要一个逻辑来为示例代码设置对象

    Akreditasi [] items = { 
                new Akreditasi (1, "Milk", 21.50), 
                new Akreditasi (2, "Butter", 15.99), 
                new Akreditasi (3, "Yogurt", 14.90), 
                new Akreditasi (4, "Toothpaste", 7.99), 
                new Akreditasi (5, "Ice Cream", 10.00), 
            };

            ArrayAdapter<Product> adapter = new ArrayAdapter<Product>(this,
                        android.R.layout.simple_list_item_1, items);
// attaching data adapter to spinner
    spinner.setAdapter(dataAdapter);

Android：如何从spinner获取数据库的索引ID

2 个答案: