Question

我对android开发很新。我知道我不应该使用重复onCreate()，但我不知道如何做到这一点。我正在同一个布局上从sqlite数据库创建两个微调器。

我的代码是：

import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Spinner;

import java.util.ArrayList;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Create DataHelper object and insert some sample data
        DataHelper datahelper = new DataHelper(this);

        datahelper.insertBreed ("Beagle");
        datahelper.insertBreed ("Bulldog");
        datahelper.insertBreed ("Chow Chow");

        // Get sample data from the database and display them in the spinner
        Spinner spinner = (Spinner) findViewById(R.id.spinnerBreeds);
        ArrayList<String> list = datahelper.getAllBreeds();
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.spinner_layout, R.id.text, list);
        spinner.setAdapter(adapter);
    }


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Create DataHelper object and insert some sample data
        DataHelper2 datahelper2 = new DataHelper2(this);

        datahelper2.insertAge("1");
        datahelper2.insertAge ("2");
        datahelper2.insertAge("3");

        // Get sample data from the database and display them in the spinner
        Spinner spinner = (Spinner) findViewById(R.id.spinnerAge);
        ArrayList<String> list = datahelper2.getAllAge();
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.spinner_layout, R.id.text, list);
        spinner.setAdapter(adapter);
    }
}

Answer 1

你有两种方法

protected void onCreate(Bundle savedInstanceState)

在您的代码中

，这就是您收到错误的原因。

您应该删除其中一个并将代码放入另一个方法中。

Answer 2

你不能在你的班级中有2个覆盖相同的方法。

只需将初始化这两个微调器的代码从第二个onCreate()复制到第一个spinner。将微调器和适配器的变量名称更改为避免重复。（例如：spinnerBreeds - ＆gt; spinnerAge / datahelper，breedsDataHelper - ＆gt; ageDataHelper / adapter，breedsAdapter - ＆gt ; ageAdapter / @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // Create DataHelper object and insert some sample data DataHelper datahelper = new DataHelper(this); datahelper.insertBreed ("Beagle"); datahelper.insertBreed ("Bulldog"); datahelper.insertBreed ("Chow Chow"); // Get sample data from the database and display them in the spinner Spinner spinnerBreeds= (Spinner) findViewById(R.id.spinnerBreeds); ArrayList<String> list = datahelper.getAllBreeds(); ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.spinner_layout, R.id.text, list); spinnerBreeds.setAdapter(adapter); //Init second spinner DataHelper2 datahelper2 = new DataHelper2(this); datahelper2.insertAge("1"); datahelper2.insertAge ("2"); datahelper2.insertAge("3"); // Get sample data from the database and display them in the spinner Spinner spinnerAge = (Spinner) findViewById(R.id.spinnerAge); ArrayList<String> list2 = datahelper2.getAllAge(); ArrayAdapter<String> adapter2 = new ArrayAdapter<String>(this, R.layout.spinner_layout, R.id.text, list2); spinnerAge.setAdapter(adapter2); }）

set

错误：方法onCreate（Bundle）已在类MainActivity中定义

2 个答案: