自定义控件-下拉菜单

下拉选择框主要是通过在EditText下用PopupWindow动态显示ListView控件来实现的。

下拉选择框可以方便用户的输入效率，以此提升用户体验。实现后的效果如下图所示。

点击EditText控件右侧的倒三角形弹出如下可选项，点击可选项，那么内容将自动填充到EditText控件中。

 

布局：

activity_main.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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<EditText
android:id="@+id/et_text"
android:layout_width="200dp"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
/>
<ImageView
android:id="@+id/iv_arrow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/down_arrow"
android:layout_alignRight="@id/et_text"
/>
</RelativeLayout>

 

item_listview.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:gravity="center_vertical"
android:padding="5dp"
>
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/user"
/>
<TextView
android:id="@+id/tv_content"
android:layout_weight="1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="ohohohoho"
android:textSize="18sp"
/>
<ImageView
android:id="@+id/iv_delete"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/delete"
/>
</LinearLayout>

 

 

package com.example.xialakuang;
import java.util.ArrayList;
import java.util.List;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.PopupWindow;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity implements OnClickListener {
private ImageView iv_arrow;
private PopupWindow popupWindow;
private EditText et;
private ListView listView;
List<String> list;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
iv_arrow = (ImageView) findViewById(R.id.iv_arrow);
et = (EditText) findViewById(R.id.et_text);
iv_arrow.setOnClickListener(this);
list = new ArrayList<String>();
for (int i = 0; i < 20; i++) {
list.add(i + "number");
}
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.iv_arrow:
// 弹出下拉框
if (popupWindow == null) {
popupWindow = new PopupWindow(this);
popupWindow.setWidth(et.getWidth());
popupWindow.setHeight(200);
listView = new ListView(this);
listView.setAdapter(new MyAdapter());
// 将ListView的分割线高度设置为0，其实保留着也行，可能比较难看就是
listView.setDividerHeight(0);
// 将ListView的滚动条隐藏
listView.setVerticalScrollBarEnabled(false);
listView.setBackgroundResource(R.drawable.listview_background);
;
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
et.setText(list.get(position));
// 下拉框消失

popupWindow.dismiss();
}
});
popupWindow.setContentView(listView);
// 设置popWindow外面的区域可以触摸
popupWindow.setOutsideTouchable(true);
// 设置popWindow可以得到焦点
popupWindow.setFocusable(true);
}
// 显示下拉框
// anchor:锚，设置下拉框显示的位置
// xoff, yoff:相当于锚的坐标
popupWindow.showAsDropDown(et, 0, 0);
break;
}
}
class MyAdapter extends BaseAdapter {
@Override
public int getCount() {
// TODO Auto-generated method stub
return list.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return null;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub

View view;
if (convertView == null) {
view = View.inflate(MainActivity.this, R.layout.item_listview, null);
} else {
view = convertView;
}
TextView textView = (TextView) view.findViewById(R.id.tv_content);
textView.setText(list.get(position));
// 设置点击侦听，删除选中的条目
ImageView imageView = (ImageView) view.findViewById(R.id.iv_delete);
imageView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub

list.remove(position);
notifyDataSetChanged();
}
});
return view;
}
}
}