感觉自己还是很少写实际应用实现的博客。最近在找实习，写博客时间少了，但还是要坚持。今天这篇博客来讲下电商应用中常见的选择类别下拉列表的实现。先看下效果图：
一、下拉列表的实现
其实实现方法有很多，这时实现的也没有什么技术含量，只是总结下自己在项目中的做法，也提供一个思路。
首先是列表的数据，一般数据都是从后台读过来，这里因为没有后台，所以写死在客户端：
private void initMenuData() {
menuData1 = new ArrayList<Map<String, String>>();
String[] menuStr1 = new String[] { "全部", "粮油", "衣服", "图书", "电子产品",
"酒水饮料", "水果" };
Map<String, String> map1;
for (int i = 0, len = menuStr1.length; i < len; ++i) {
map1 = new HashMap<String, String>();
map1.put("name", menuStr1[i]);
menuData1.add(map1);
}
menuData2 = new ArrayList<Map<String, String>>();
String[] menuStr2 = new String[] { "综合排序", "配送费最低" };
Map<String, String> map2;
for (int i = 0, len = menuStr2.length; i < len; ++i) {
map2 = new HashMap<String, String>();
map2.put("name", menuStr2[i]);
menuData2.add(map2);
}
menuData3 = new ArrayList<Map<String, String>>();
String[] menuStr3 = new String[] { "优惠活动", "特价活动", "免配送费",
"可在线支付" };
Map<String, String> map3;
for (int i = 0, len = menuStr3.length; i < len; ++i) {
map3 = new HashMap<String, String>();
map3.put("name", menuStr3[i]);
menuData3.add(map3);
}
}
就是做了简单的封装。弹出列表的实现考虑使用Popwindow。
popMenu = new PopupWindow(contentView,
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
popMenu.setOutsideTouchable(true);
popMenu.setBackgroundDrawable(new BitmapDrawable());
popMenu.setFocusable(true);
popMenu.setAnimationStyle(R.style.popwin_anim_style);
popMenu.setOnDismissListener(new OnDismissListener() {
public void onDismiss() {
productTv.setTextColor(Color.parseColor("#5a5959"));
sortTv.setTextColor(Color.parseColor("#5a5959"));
activityTv.setTextColor(Color.parseColor("#5a5959"));
}
});
接着将数据封装到adapter中：
menuAdapter1 = new SimpleAdapter(this, menuData1,
R.layout.item_listview_popwin, new String[] { "name" },
new int[] { R.id.listview_popwind_tv });
menuAdapter2 = new SimpleAdapter(this, menuData2,
R.layout.item_listview_popwin, new String[] { "name" },
new int[] { R.id.listview_popwind_tv });
menuAdapter3 = new SimpleAdapter(this, menuData3,
R.layout.item_listview_popwin, new String[] { "name" },
new int[] { R.id.listview_popwind_tv });
设置点击标题头弹出列表，并改变标题头的颜色
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.supplier_list_product:
productTv.setTextColor(Color.parseColor("#39ac69"));
popListView.setAdapter(menuAdapter1);
popMenu.showAsDropDown(product, 0, 2);
menuIndex = 0;
break;
case R.id.supplier_list_sort:
sortTv.setTextColor(Color.parseColor("#39ac69"));
popListView.setAdapter(menuAdapter2);
popMenu.showAsDropDown(product, 0, 2);
menuIndex = 1;
break;
case R.id.supplier_list_activity:
activityTv.setTextColor(Color.parseColor("#39ac69"));
popListView.setAdapter(menuAdapter3);
popMenu.showAsDropDown(product, 0, 2);
menuIndex = 2;
break;
}
}
showAsDropDown是为了让popwindow定位在Product这个选择标题的正下方。从而实现上面那种方式。
最后完整的贴出代码，还是蛮简单的。最后也会提供代码下载链接。
public class MainActivity extends Activity implements
OnClickListener {
private ListView listView, popListView;
private ProgressBar progressBar;
private List<Map<String, String>> menuData1, menuData2, menuData3;
private PopupWindow popMenu;
private SimpleAdapter menuAdapter1, menuAdapter2, menuAdapter3;
private LinearLayout product, sort, activity;
private ImageView cartIv;
private TextView productTv, sortTv, activityTv, titleTv;
private int green, grey;
private String currentProduct, currentSort, currentActivity;
private int menuIndex = 0;
private Intent intent;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_supplier_list);
findView();
initMenuData();
initPopMenu();
}
private void initMenuData() {
menuData1 = new ArrayList<Map<String, String>>();
String[] menuStr1 = new String[] { "全部", "粮油", "衣服", "图书", "电子产品",
"酒水饮料", "水果" };
Map<String, String> map1;
for (int i = 0, len = menuStr1.length; i < len; ++i) {
map1 = new HashMap<String, String>();
map1.put("name", menuStr1[i]);
menuData1.add(map1);
}
menuData2 = new ArrayList<Map<String, String>>();
String[] menuStr2 = new String[] { "综合排序", "配送费最低" };
Map<String, String> map2;
for (int i = 0, len = menuStr2.length; i < len; ++i) {
map2 = new HashMap<String, String>();
map2.put("name", menuStr2[i]);
menuData2.add(map2);
}
menuData3 = new ArrayList<Map<String, String>>();
String[] menuStr3 = new String[] { "优惠活动", "特价活动", "免配送费",
"可在线支付" };
Map<String, String> map3;
for (int i = 0, len = menuStr3.length; i < len; ++i) {
map3 = new HashMap<String, String>();
map3.put("name", menuStr3[i]);
menuData3.add(map3);
}
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.supplier_list_product:
productTv.setTextColor(Color.parseColor("#39ac69"));
popListView.setAdapter(menuAdapter1);
popMenu.showAsDropDown(product, 0, 2);
menuIndex = 0;
break;
case R.id.supplier_list_sort:
sortTv.setTextColor(Color.parseColor("#39ac69"));
popListView.setAdapter(menuAdapter2);
popMenu.showAsDropDown(product, 0, 2);
menuIndex = 1;
break;
case R.id.supplier_list_activity:
activityTv.setTextColor(Color.parseColor("#39ac69"));
popListView.setAdapter(menuAdapter3);
popMenu.showAsDropDown(product, 0, 2);
menuIndex = 2;
break;
}
}
protected void findView() {
listView = (ListView) findViewById(R.id.supplier_list_lv);
product = (LinearLayout) findViewById(R.id.supplier_list_product);
sort = (LinearLayout) findViewById(R.id.supplier_list_sort);
activity = (LinearLayout) findViewById(R.id.supplier_list_activity);
productTv = (TextView) findViewById(R.id.supplier_list_product_tv);
sortTv = (TextView) findViewById(R.id.supplier_list_sort_tv);
activityTv = (TextView) findViewById(R.id.supplier_list_activity_tv);
titleTv = (TextView) findViewById(R.id.supplier_list_title_tv);
cartIv = (ImageView) findViewById(R.id.supplier_list_cart_iv);
progressBar = (ProgressBar) findViewById(R.id.progress);
product.setOnClickListener(this);
sort.setOnClickListener(this);
activity.setOnClickListener(this);
cartIv.setOnClickListener(this);
}
private void initPopMenu() {
initMenuData();
View contentView = View.inflate(this, R.layout.popwin_supplier_list,
null);
popMenu = new PopupWindow(contentView,
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
popMenu.setOutsideTouchable(true);
popMenu.setBackgroundDrawable(new BitmapDrawable());
popMenu.setFocusable(true);
popMenu.setAnimationStyle(R.style.popwin_anim_style);
popMenu.setOnDismissListener(new OnDismissListener() {
public void onDismiss() {
productTv.setTextColor(Color.parseColor("#5a5959"));
sortTv.setTextColor(Color.parseColor("#5a5959"));
activityTv.setTextColor(Color.parseColor("#5a5959"));
}
});
popListView = (ListView) contentView
.findViewById(R.id.popwin_supplier_list_lv);
contentView.findViewById(R.id.popwin_supplier_list_bottom)
.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
popMenu.dismiss();
}
});
menuAdapter1 = new SimpleAdapter(this, menuData1,
R.layout.item_listview_popwin, new String[] { "name" },
new int[] { R.id.listview_popwind_tv });
menuAdapter2 = new SimpleAdapter(this, menuData2,
R.layout.item_listview_popwin, new String[] { "name" },
new int[] { R.id.listview_popwind_tv });
menuAdapter3 = new SimpleAdapter(this, menuData3,
R.layout.item_listview_popwin, new String[] { "name" },
new int[] { R.id.listview_popwind_tv });
popListView.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> arg0, View arg1, int pos,
long arg3) {
popMenu.dismiss();
if (menuIndex == 0) {
currentProduct = menuData1.get(pos).get("name");
titleTv.setText(currentProduct);
productTv.setText(currentProduct);
Toast.makeText(MainActivity.this, currentProduct, Toast.LENGTH_SHORT).show();
} else if (menuIndex == 1) {
currentSort = menuData2.get(pos).get("name");
titleTv.setText(currentSort);
sortTv.setText(currentSort);
Toast.makeText(MainActivity.this, currentSort, Toast.LENGTH_SHORT).show();
} else {
currentActivity = menuData3.get(pos).get("name");
titleTv.setText(currentActivity);
activityTv.setText(currentActivity);
Toast.makeText(MainActivity.this, currentActivity, Toast.LENGTH_SHORT).show();
}
}
});
}
}
二、加载圆形ProgressBar的显示
就是效果图中的那种加载ProgressBar，圆形ProgresBar可以用原生的Bar来实现，但样式单一，之前我做这种效果第一时间总是考虑到帧动画，但用这种方式需要有很多图片来链接起来，这样一来实现麻烦，二来图片多了占内存。下面用改变原生ProgressBar的动画来实现这种效果，非常简单：
<ProgressBar
android:id="@+id/progress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:indeterminateDrawable="@drawable/shape_progress"
android:indeterminateDuration="1000" />
indeterminateDrawable是加载背景图片，indeterminateDuration是旋转的速度。这里的思路是用xml来画一张图，它是环形的，且环形圈中有渐变颜色。如下：
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
android:fromDegrees="0"
android:pivotX="50%"
android:pivotY="50%"
android:toDegrees="360" >
<shape
android:innerRadiusRatio="3"
android:shape="ring"
android:thicknessRatio="10"
android:useLevel="false" >
<gradient
android:centerColor="#8cd4aa"
android:centerY="0.50"
android:endColor="#ffffff"
android:startColor="#39ac69"
android:type="sweep"
android:useLevel="false" />
</shape>
</rotate>
rotate设置旋转动画，360度旋转。shape="ring"设置背景为圆。android:innerRadiusRatio="3"设置内环半径，android:thicknessRatio="10"设置外环半径。最后为了让环中颜色有渐变效果，使用gradient来设置。gradient可以有三种渐变方式，线性，辐射，扫描。这里type要设置成扫描。然后设置中心点，开始颜色和结束颜色，就能实现上面的那种效果了。
好了，到这里整个效果就讲完了。贴上源码下载地址：