Question

我正在尝试通过三个类完成控制自定义ListView的代码：AdapterListView，ItemListView和MainActivity。

到目前为止，代码只能通过AdapterListView输入数据和图片（由代码插入）。

我在item_list.xml两个按钮中添加了一个按钮，用于从列表中删除项目，另一个按钮用于编辑列表项。

我尝试实施该方法以移除该项并插入我的AdapterListView，但我不知道如何在MainActivity中调用它。

    public void deletaItem(View v) {
    adapterListView.removeItem(?????);
    }

我还需要知道如何在点击编辑按钮后编辑该项目。

在三个项目类之下：

AdapterListView

package com.example.aulasandroid.aulas_android_listviewactions;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.ArrayList;

/**
* Created by lmontanhine on 11/2/2015.
*/
public class AdapterListView extends BaseAdapter {

private LayoutInflater mInflater;
private ArrayList<ItemListView> itens;

public AdapterListView(Context context, ArrayList<ItemListView> itens) {
    //Itens que preencheram o listview
    this.itens = itens;
    //responsavel por pegar o Layout do item.
    mInflater = LayoutInflater.from(context);
}

/**
 * Retorna a quantidade de itens
 *
 * @return
 */
public int getCount() {
    return itens.size();
}

/**
 * Retorna o item de acordo com a posicao dele na tela.
 *
 * @param position
 * @return
 */
public ItemListView getItem(int position) {
    return itens.get(position);
}

/**
 * Sem implementação
 *
 * @param position
 * @return
 */
public long getItemId(int position) {
    return position;
}

public View getView(int position, View view, ViewGroup parent) {
    //Pega o item de acordo com a posção.
    ItemListView item = itens.get(position);
    //infla o layout para podermos preencher os dados
    view = mInflater.inflate(R.layout.item_list, null);

    //atraves do layout pego pelo LayoutInflater, pegamos cada id relacionado
    //ao item e definimos as informações.
    ((TextView) view.findViewById(R.id.text)).setText(item.getTexto());
    ((ImageView) view.findViewById(R.id.imagemview)).setImageResource(item.getIconeRid());

    return view;
}
public void removeItem(int positionToRemove){
    itens.remove(positionToRemove);
    notifyDataSetChanged();
}
}

ItemListView

package com.example.aulasandroid.aulas_android_listviewactions;

/**
* Created by lmontanhine on 11/2/2015.
*/
public class ItemListView {

private String texto;
private int iconeRid;

public ItemListView() {
}

public ItemListView(String texto, int iconeRid) {
    this.texto = texto;
    this.iconeRid = iconeRid;
}

public int getIconeRid() {
    return iconeRid;
}

public void setIconeRid(int iconeRid) {
    this.iconeRid = iconeRid;
}

public String getTexto() {
    return texto;
}

public void setTexto(String texto) {
    this.texto = texto;
}
}

MainActivity

package com.example.aulasandroid.aulas_android_listviewactions;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;


public class MainActivity extends Activity implements    AdapterView.OnItemClickListener {

private ListView listView;
private AdapterListView adapterListView;
private ArrayList<ItemListView> itens;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //carrega o layout onde contem o ListView
    setContentView(R.layout.activity_main);

    //Pega a referencia do ListView
    listView = (ListView) findViewById(R.id.list);
    //Define o Listener quando alguem clicar no item.
    listView.setOnItemClickListener(this);

    createListView();
}

private void createListView() {
    //Criamos nossa lista que preenchera o ListView
    itens = new ArrayList<ItemListView>();
    ItemListView item1 = new ItemListView("Felpudo", R.drawable.felpudo);
    ItemListView item2 = new ItemListView("Felpudão", R.drawable.felpudo1);
    ItemListView item3 = new ItemListView("Felpudinho", R.drawable.felpudo2);

    itens.add(item1);
    itens.add(item2);
    itens.add(item3);

    //Cria o adapter
    adapterListView = new AdapterListView(this, itens);

    //Define o Adapter
    listView.setAdapter(adapterListView);
    //Cor quando a lista é selecionada para ralagem.
    listView.setCacheColorHint(Color.TRANSPARENT);
}

public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
    //Pega o item que foi selecionado.
    ItemListView item = adapterListView.getItem(arg2);
    //Demostração
    Toast.makeText(this, "Você Clicou em: " + item.getTexto(), Toast.LENGTH_LONG).show();
}

public void deletaItem(View v) {
    adapterListView.removeItem();
}
}

item_list.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:padding="5sp">
    <ImageView
        android:id="@+id/imagemview"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        />
    <Button
        android:id="@+id/btnEdit"
        android:layout_width="80dp"
        android:layout_height="40dp"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:focusable="false"
        android:focusableInTouchMode="false"
        android:text="Editar"
        android:textColor="#FFFFFF"/>

    <Button
        android:id="@+id/btnDelete"
        android:layout_width="80dp"
        android:layout_height="40dp"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/btnEdit"
        android:layout_marginTop="3dp"
        android:focusable="false"
        android:focusableInTouchMode="false"
        android:text="Deletar"
        android:textColor="#FFFFFF"
        android:onClick="deletaItem"/>
    <TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerVertical="true"
        android:layout_marginLeft="115sp"
        android:gravity="center_vertical"
        android:textColor="#FF000000"
        />

</RelativeLayout>
</RelativeLayout>

Answer 1

在getView方法中，您可以为每个删除按钮设置一个标记，如：

((Button) view.findViewById(R.id.btnDelete)).setTag(position);

（position是适配器内getView的第一个参数）。

然后，在deletaItem方法中，您可以请求v.getTag（），该值将是removeItem的参数。

public void deletaItem(View v) {
    adapterListView.removeItem(v.getTag());
}

编辑：几乎一样。

在适配器的getView内：

((Button) view.findViewById(R.id.btnEdit)).setTag(position);

在适配器类中，创建一个新方法，如：

public void editItem(int position) {
    // edit behavior
    .
    .
    .
    notifyDataSetChanged();
}

内部活动：

public void onClickEditButton(View v) {
    adapterListView.editItem(v.getTag());
}

另外，不要忘记在item_list.xml上添加onClick =“onClickEditButton”

希望它有所帮助：D

编辑2：编辑项目文本

 public void editItem(int position) {
    getItem(position).setTexto("new text");
    notifyDataSetChanged();
 }

在ListView中自定义适配器

1 个答案: