Popupwindow实现下拉菜单

一般输入框右边有一个下拉菜单，供用户选择以前曾输入过的内容，例如账号等一些信息，下拉菜单的实现有很多种方式，现在使用Popupwindow组件实现这个功能，Popupwindow内的组件使用一个ListView显示用户以前输过的信息，简单实现的效果如下图：

当用户点击某个item子项时就把该内容显示到输入框上，右边的按钮供用户删除掉某些信息。贴出代码：

package com.ex91;


import java.util.ArrayList;
import java.util.List;


import android.app.Activity;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.view.ViewGroup.LayoutParams;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.PopupWindow;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;


public class MainActivity extends Activity implements OnItemClickListener, OnClickListener {
private ListView mList;
private MyAdapter mAdapter;
private EditText mEdit;
private PopupWindow mPop;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
initView();
}
private void initView() {
mEdit = (EditText) findViewById(R.id.editText1);
ImageView mImage = (ImageView) findViewById(R.id.imageView1);
mImage.setOnClickListener(this);
mList = (ListView) getLayoutInflater().inflate(
R.layout.listview, null);
mList.setOnItemClickListener(this);
mAdapter = new MyAdapter();
mList.setAdapter(mAdapter);

}
public void initPop(){
int width = mEdit.getWidth();
int height = LayoutParams.WRAP_CONTENT;
mPop = new PopupWindow(mList, width, height, true);

//注意要加这句代码，点击弹出窗口其它区域才会让窗口消失
mPop.setBackgroundDrawable(new ColorDrawable(0xffffffff));

}


class MyAdapter extends BaseAdapter{
List<String> mList = new ArrayList<String>();
public MyAdapter()
{
mList.add("12345");
mList.add("324215");
mList.add("324665");
mList.add("32450");
mList.add("32765");
}
public int getCount() {
// TODO Auto-generated method stub
return mList.size();
}


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


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


@Override
public View getView(final int position, View convertView,
ViewGroup parent) {
View view = null;
ViewHolder holder = null;
if(convertView==null){
view = getLayoutInflater().inflate(R.layout.item, null);
holder = new ViewHolder();
holder.mText = (TextView) view.findViewById(R.id.tv);
holder.mImage = (ImageView) view.findViewById(R.id.delete);
holder.mImage.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mList.remove(position);
notifyDataSetChanged();
}
});
view.setTag(holder);
}else {
view = convertView;
holder = (ViewHolder) view.getTag();
}
holder.mText.setText(mList.get(position));
return view;
}

}
class ViewHolder {
TextView mText;
ImageView mImage;
}
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
String string = mAdapter.mList.get(position);
mEdit.setText(string);
mPop.dismiss();
}


@Override
public void onClick(View v) {
if(mPop==null){
initPop();
}
if(!mPop.isShowing()){
mPop.showAsDropDown(mEdit,0,-5);
}else{
mPop.dismiss();
}
}
}