android - 如何使用 onclick 方法从列表视图中获取行的 ID？

Question

我正在从数据库中返回这些数据，

@Override
public ArrayList < String > returnProducerData(String entereduser_id) {

        Cursor c = db.rawQuery("Select * from  producer_table WHERE user_id= "+entereduser_id, null);
        ArrayList<String> producerResult = new ArrayList<String>();

        int ProducerId = c.getColumnIndex(PRODUCER_ID);
        int UserId= c.getColumnIndex(USER_ID);
        int ProducerName = c.getColumnIndex(PRODUCER_NAME);
        int ProducerSurname = c.getColumnIndex(PRODUCER_SURNAME);

        for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
            producerResult.add(c.getString(ProducerId) +" "+c.getString(UserId) +" "+ c.getString(ProducerName) +" "+ c.getString(ProducerSurname) );

        }

        return producerResult;

}   

我正在使用这种方法在列表视图中显示数据

 HashMap<String, String> user = session.getUserDetails();
 String user_id= user.get(SessionManager.USER_ID);
 ArrayList<String> data = info.returnProducerData(user_id); 

    //set all data as listview using Array
    listView.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, data));
    //set listview action
    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
            // TODO Auto-generated method stub
            String UserInfo = listView.getItemAtPosition(position).toString(); 
            Intent i =new Intent(ShowProducerTable.this, TestDataBase.class);
                  i.putExtra("UserInfo", UserInfo);
                  startActivity(i);
                  /***just to check if it has value***/             
           // Toast.makeText(getBaseContext(),"position is : "+position+" and value is "+UserInfo,Toast.LENGTH_SHORT).show();
                  Toast.makeText(getBaseContext(), id + "", Toast.LENGTH_LONG).show();
        }
    });

现在我想查看我单击的行的 producer_id。

请你帮助我好吗？

Answer 1

String productIDAsString;

for(int i= 0; i < UserInfo.length;i+++) {
    if(!(Userinfo.substring(i,i+1).equals(" ")) {
        productIDAsString += UserInfo.substring(i,i+1);
    }
}
int productID = Integer.parseInt(productIDAsString);

Answer 2

使用CursorAdapter框架提供的实现之一。通过这种方式，位置返回的项目getItemAtPosition，在Cursor移动的位置，您可以从中轻松提取所需的信息，避免难以跟踪/调试并可能导致严重崩溃的黑客攻击

Answer 3

listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {

    @Override
    public void onItemClick(AdapterView<?> parent, View view,
            int position, long id) {
        // TODO Auto-generated method stub
        String UserInfo = listView.getItemAtPosition(position).toString(); 
       String userId = UserInfo.substring(0, UserInfo .indexOf(" "));
        Intent i =new Intent(ShowProducerTable.this, TestDataBase.class);
              i.putExtra("UserInfo", UserInfo);
              startActivity(i);
              /***just to check if it has value***/             
       // Toast.makeText(getBaseContext(),"position is : "+position+" and value is +UserInfo,Toast.LENGTH_SHORT).show();
              Toast.makeText(getBaseContext(), id + "", Toast.LENGTH_LONG).show();
    }
});

请参阅“String userId = UserInfo.substring(0, UserInfo .indexOf(" "));”行 在代码中...您将获得用户 ID。

Answer 4

或者您可以创建另一个 POJO 类来保存从数据库返回的数据并使用它的 getter 方法，您将能够获得所需的结果，例如：

public ArrayList < Producer > returnProducerData(String entereduser_id) {

    Cursor c = db.rawQuery("Select * from  producer_table WHERE user_id= "+entereduser_id, null);
    ArrayList<Producer> producerResult = new ArrayList<Producer>();

    int ProducerId = c.getColumnIndex(PRODUCER_ID);
    int UserId= c.getColumnIndex(USER_ID);
    int ProducerName = c.getColumnIndex(PRODUCER_NAME);
    int ProducerSurname = c.getColumnIndex(PRODUCER_SURNAME);

    for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
        Producer producer = new Producer();
        producer.setId(c.getString(ProducerId));
        producer.setUserId(c.getString(UserId));
        producer.setName(c.getString(ProducerName));
        producer.setSurname(c.getString(ProducerSurname));
        producerResult.add(producer);

    }

    return producerResult;

}

然后为您的列表视图使用自定义适配器，在 onItemClick 方法中，您可以通过调用 producer.getUserID() 方法来访问 id。