Question

所以我对Android开发很新，并且一直试图拼凑一些代码位。这是我到目前为止所做的：

package com.teslaprime.prirt;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.AdapterView.OnItemClickListener;
import java.util.ArrayList;
import java.util.List;

public class TaskList extends Activity {
  List<Task> model = new ArrayList<Task>();
  ArrayAdapter<Task> adapter = null;

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Button add = (Button) findViewById(R.id.add);
    add.setOnClickListener(onAdd);

    ListView list = (ListView) findViewById(R.id.tasks);

    adapter = new ArrayAdapter<Task>(this,android.R.layout.simple_list_item_1,model);
    list.setAdapter(adapter);
    list.setOnItemClickListener(new OnItemClickListener() {
      public void onItemClick(View v, int position, long id) {
        adapter.remove(position);
      }
    });}

  private View.OnClickListener onAdd = new View.OnClickListener() {
    public void onClick(View v) {
      Task task = new Task();
      EditText name = (EditText) findViewById(R.id.taskEntry);

      task.name = name.getText().toString();

      adapter.add(task);
    }
  };
}

以下是我得到的错误：

compile:
    [javac] /opt/android-sdk/tools/ant/main_rules.xml:384: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
    [javac] Compiling 2 source files to /home/chris-kun/code/priRT/bin/classes
    [javac] /home/chris-kun/code/priRT/src/com/teslaprime/prirt/TaskList.java:30: <anonymous com.teslaprime.prirt.TaskList$1> is not abstract and does not override abstract method onItemClick(android.widget.AdapterView<?>,android.view.View,int,long) in android.widget.AdapterView.OnItemClickListener
    [javac]     list.setOnItemClickListener(new OnItemClickListener() {
    [javac]                                                           ^
    [javac] /home/chris-kun/code/priRT/src/com/teslaprime/prirt/TaskList.java:32: remove(com.teslaprime.prirt.Task) in android.widget.ArrayAdapter<com.teslaprime.prirt.Task> cannot be applied to (int)
    [javac]         adapter.remove(position);
    [javac]                ^
    [javac] 2 errors

BUILD FAILED
/opt/android-sdk/tools/ant/main_rules.xml:384: Compile failed; see the compiler error output for details.

Total time: 2 seconds

任何想法？

Answer 1

我不是Android程序员，但它指的是这一行：

list.setOnItemClickListener(new OnItemClickListener() {
  public void onItemClick(View v, int position, long id) {
    adapter.remove(position);
  }
});}

你有方法签名View，int，long，它想要

AdapterView<?> parent, View view, int position, long id as the signature

关于第二个问题，它是说

适配器的remove方法需要Task对象而不是整数。

Answer 2

abstract类包含未实现的方法。如果要扩展它，则必须实现未实现的方法。 Eclipse将告诉您何时不执行必要操作，如果单击红色“x”，将为您提供这些问题的建议解决方案。在这种情况下，它将自动包含您尚未实现的这些抽象方法的方法签名。

“不是抽象的，也不会覆盖抽象方法。”

2 个答案: