Android 使用adapter的两种回调数据方式

1、首先创建一个listView列表，用于显示数据：

<ListView
android:id="@+id/listView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>

item布局使用简单的一行文字显示，主要是将点击的位置回调回使用listView的类文件之中，item.xml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">

<TextView
android:id="@+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:padding="10dp" />

</RelativeLayout>

2、回调数据分为两种方式，第一种是在adapter之中写一个回调接口，在点击item的时候使用接口回调，将点击的position传递给activity之中使用的adapter，在adapter中使用定义的回调方法获取到传递的position。第二种是在activity之中传递数据到adapter的时候将handler一并传进去，使用handler获取到点listView点击之时的position传递。

（1）使用接口回调：

i、自定义适配器MyAdapter：

public class MyAdapter extends BaseAdapter {

private List<String> list;
private Context context;
private LayoutInflater inflater;
private onClickMyTextView onClickMyTextView;

public MyAdapter(Context context, List<String> list) {
super();
inflater = LayoutInflater.from(context);
this.list = list;
this.context = context;
}

//接口回调
public interface onClickMyTextView{
public void myTextViewClick(int id);
}
public void setOnClickMyTextView(onClickMyTextView onClickMyTextView) {
this.onClickMyTextView = onClickMyTextView;
}

@Override
public int getCount() {
return list.size();
}

@Override
public Object getItem(int position) {
return list.get(position);
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {

ViewHolder viewHolder = null;
if (viewHolder==null) {
viewHolder = new ViewHolder();
convertView = inflater.inflate(R.layout.item, null);
viewHolder.textView = (TextView) convertView.findViewById(R.id.textView);

convertView.setTag(viewHolder);
}else {
viewHolder = (ViewHolder) convertView.getTag();
}

viewHolder.textView.setText(list.get(position).toString());

if (onClickMyTextView!=null) {
viewHolder.textView.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
onClickMyTextView.myTextViewClick(position);

}
});
}

return convertView;
}

class ViewHolder{
TextView textView;
}

}

使用自定义接口设置：

public interface onClickMyTextView{
public void myTextViewClick(int id);
}
public void setOnClickMyTextView(onClickMyTextView onClickMyTextView) {
this.onClickMyTextView = onClickMyTextView;
}

点击的时候使用接口传递数据：

if (onClickMyTextView!=null) {
viewHolder.textView.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
onClickMyTextView.myTextViewClick(position);

}
});
}

ii、在MainActivity之中使用adapter：

public class MainActivity extends Activity {

private ListView listView;
private List<String> list;
private MyAdapter adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

listView = (ListView) findViewById(R.id.listView);

initData();

adapter = new MyAdapter(MainActivity.this, list);
listView.setAdapter(adapter);
//接口的调用，获取传递的id
adapter.setOnClickMyTextView(new onClickMyTextView() {

@Override
public void myTextViewClick(int id) {
Toast.makeText(MainActivity.this, list.get(id).toString(), Toast.LENGTH_SHORT).show();

}
});
}

// 列表模拟数据
private void initData() {
list = new ArrayList<String>();
for (int i = 0; i < 20; i++) {
list.add("添加的数据条目=" + i);
}

}

}

（2）、使用Handler回调数据：

i、自定义适配器MyAdapter：

public class MyAdapter extends BaseAdapter {

public static final String POSITION = "POSITION";
public static final int DELETE = 1;

private List<String> list;
private Context context;
private LayoutInflater inflater;
private Handler handler;

public MyAdapter(Context context, List<String> list, Handler handler) {
super();
inflater = LayoutInflater.from(context);
this.list = list;
this.context = context;
this.handler = handler;
}

@Override
public int getCount() {
return list.size();
}

@Override
public Object getItem(int position) {
return list.get(position);
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {

ViewHolder viewHolder = null;
if (viewHolder == null) {
viewHolder = new ViewHolder();
convertView = inflater.inflate(R.layout.item, null);
viewHolder.textView = (TextView) convertView.findViewById(R.id.textView);

convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}

viewHolder.textView.setOnClickListener(new OnItemChildClickListener(DELETE, position));

return convertView;
}

class ViewHolder {
TextView textView;
}

// handler的点击事件
private class OnItemChildClickListener implements View.OnClickListener {
// 点击类型索引，对应前面的CLICK_INDEX
private int clickIndex;
// 点击列表位置
private int position;

public OnItemChildClickListener(int clickIndex, int position) {
this.clickIndex = clickIndex;
this.position = position;
}

@Override
public void onClick(View v) {
// 创建Message并填充数据，通过handle联系Activity接收处理
Message msg = new Message();
msg.what = clickIndex;
msg.arg1 = position;
Bundle b = new Bundle();
b.putInt(POSITION, position);
msg.setData(b);
handler.sendMessage(msg);
}

}

}

点击事件的使用：

viewHolder.textView.setOnClickListener(new OnItemChildClickListener(DELETE, position));

点击方法，将position传递到handler之中：

// handler的点击事件
private class OnItemChildClickListener implements View.OnClickListener {
// 点击类型索引，对应前面的CLICK_INDEX
private int clickIndex;
// 点击列表位置
private int position;

public OnItemChildClickListener(int clickIndex, int position) {
this.clickIndex = clickIndex;
this.position = position;
}

@Override
public void onClick(View v) {
// 创建Message并填充数据，通过handle联系Activity接收处理
Message msg = new Message();
msg.what = clickIndex;
msg.arg1 = position;
Bundle b = new Bundle();
b.putInt(POSITION, position);
msg.setData(b);
handler.sendMessage(msg);
}

}

ii、在MainActivity之中使用adapter：

public class MainActivity extends Activity {

/**
* 显示数据的列表
*/
private ListView listView;
/**
* 模拟数据的集合
*/
private List<String> list;
/**
* 自定义的适配器
*/
private MyAdapter adapter;
/**
* 回传回来的列表位置
*/
private int mPosition;

private Handler handler = new Handler() {
public void handleMessage(Message msg) {

// 回传的是此item的bean,对当前bean中的数据能够进行操作,位置传过来之后还能将数据进行操作
mPosition = msg.getData().getInt(MyAdapter.POSITION);

switch (msg.what) {
case MyAdapter.DELETE:
Toast.makeText(MainActivity.this, "点击回传的是:" + list.get(mPosition), Toast.LENGTH_SHORT).show();
break;

default:
break;
}
};
};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

listView = (ListView) findViewById(R.id.listView);

initData();

adapter = new MyAdapter(MainActivity.this, list, handler);
listView.setAdapter(adapter);
}

private void initData() {
list = new ArrayList<String>();
for (int i = 0; i < 20; i++) {
list.add("添加的数据条目=" + i);
}

}

}