首先,第一步要在layout中新建一个activity_title.xml
<RelativeLayout
android:id="@+id/title"
android:layout_width="fill_parent"
android:layout_height="45dp"
android:background="@drawable/title_bar"
android:gravity="center_vertical" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="微信"
android:textColor="#ffffff"
android:textSize="20sp" />
<ImageButton
android:id="@+id/title_btn"
android:layout_width="67dp"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_marginRight="5dp"
android:background="@drawable/title_button"
android:onClick="btnmainright"
android:src="@drawable/title_btn_function" />
</RelativeLayout>
第二步,新建一个activity继承PopupWindow,实现标题按钮上的弹窗
public class TitlePopup extends PopupWindow {
private Context mContext;
//列表弹窗的间隔
protected final int LIST_PADDING = 10;
//实例化一个矩形
private Rect mRect = new Rect();
//坐标的位置(x、y)
private final int[] mLocation = new int[2];
//屏幕的宽度和高度
private int mScreenWidth,mScreenHeight;
//判断是否需要添加或更新列表子类项
private boolean mIsDirty;
//位置不在中心
private int popupGravity = Gravity.NO_GRAVITY;
//弹窗子类项选中时的监听
private OnItemOnClickListener mItemOnClickListener;
//定义列表对象
private ListView mListView;
//定义弹窗子类项列表
private ArrayList<ActionItem> mActionItems = new ArrayList<ActionItem>();
public TitlePopup(Context context){
//设置布局的参数
this(context, LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
}
public TitlePopup(Context context, int width, int height){
this.mContext = context;
//设置可以获得焦点
setFocusable(true);
//设置弹窗内可点击
setTouchable(true);
//设置弹窗外可点击
setOutsideTouchable(true);
//获得屏幕的宽度和高度
mScreenWidth = Util.getScreenWidth(mContext);
mScreenHeight = Util.getScreenHeight(mContext);
//设置弹窗的宽度和高度
setWidth(width);
setHeight(height);
setBackgroundDrawable(new BitmapDrawable());
//设置弹窗的布局界面
setContentView(LayoutInflater.from(mContext).inflate(R.layout.title_popup, null));
initUI();
}
/**
* 初始化弹窗列表
*/
private void initUI(){
mListView = (ListView) getContentView().findViewById(R.id.title_list);
mListView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int index,long arg3) {
//点击子类项后,弹窗消失
dismiss();
if(mItemOnClickListener != null)
mItemOnClickListener.onItemClick(mActionItems.get(index), index);
}
});
}
/**
* 显示弹窗列表界面
*/
public void show(View view){
//获得点击屏幕的位置坐标
view.getLocationOnScreen(mLocation);
//设置矩形的大小
mRect.set(mLocation[0], mLocation[1], mLocation[0] + view.getWidth(),mLocation[1] + view.getHeight());
//判断是否需要添加或更新列表子类项
if(mIsDirty){
populateActions();
}
//显示弹窗的位置
showAtLocation(view, popupGravity, mScreenWidth - LIST_PADDING - (getWidth()/2), mRect.bottom);
}
/**
* 设置弹窗列表子项
*/
private void populateActions(){
mIsDirty = false;
//设置列表的适配器
mListView.setAdapter(new BaseAdapter() {
@Override
public View getView(int position, View convertView, ViewGroup parent) {
TextView textView = null;
if(convertView == null){
textView = new TextView(mContext);
textView.setTextColor(mContext.getResources().getColor(android.R.color.white));
textView.setTextSize(14);
//设置文本居中
textView.setGravity(Gravity.CENTER);
//设置文本域的范围
textView.setPadding(0, 10, 0, 10);
//设置文本在一行内显示(不换行)
textView.setSingleLine(true);
}else{
textView = (TextView) convertView;
}
ActionItem item = mActionItems.get(position);
//设置文本文字
textView.setText(item.mTitle);
//设置文字与图标的间隔
textView.setCompoundDrawablePadding(10);
//设置在文字的左边放一个图标
textView.setCompoundDrawablesWithIntrinsicBounds(item.mDrawable, null , null, null);
return textView;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public Object getItem(int position) {
return mActionItems.get(position);
}
@Override
public int getCount() {
return mActionItems.size();
}
}) ;
}
/**
* 添加子类项
*/
public void addAction(ActionItem action){
if(action != null){
mActionItems.add(action);
mIsDirty = true;
}
}
/**
* 清除子类项
*/
public void cleanAction(){
if(mActionItems.isEmpty()){
mActionItems.clear();
mIsDirty = true;
}
}
/**
* 根据位置得到子类项
*/
public ActionItem getAction(int position){
if(position < 0 || position > mActionItems.size())
return null;
return mActionItems.get(position);
}
/**
* 设置监听事件
*/
public void setItemOnClickListener(OnItemOnClickListener onItemOnClickListener){
this.mItemOnClickListener = onItemOnClickListener;
}
/**
* @author yangyu
* 功能描述:弹窗子类项按钮监听事件
*/
public static interface OnItemOnClickListener{
public void onItemClick(ActionItem item , int position);
}
在新建一个class文件得到弹窗内部的子内项(绘制的图标,按钮)
public class ActionItem {
//定义图片对象
public Drawable mDrawable;
//定义文本对象
public CharSequence mTitle;
public ActionItem(Drawable drawable, CharSequence title){
this.mDrawable = drawable;
this.mTitle = title;
}
public ActionItem(Context context, int titleId, int drawableId){
this.mTitle = context.getResources().getText(titleId);
this.mDrawable = context.getResources().getDrawable(drawableId);
}
public ActionItem(Context context, CharSequence title, int drawableId) {
this.mTitle = title;
this.mDrawable = context.getResources().getDrawable(drawableId);
}
封装的常量工具类
public class Util {
/**
* 得到设备屏幕的宽度
*/
public static int getScreenWidth(Context context) {
return context.getResources().getDisplayMetrics().widthPixels;
}
/**
* 得到设备屏幕的高度
*/
public static int getScreenHeight(Context context) {
return context.getResources().getDisplayMetrics().heightPixels;
}
/**
* 得到设备的密度
*/
public static float getScreenDensity(Context context) {
return context.getResources().getDisplayMetrics().density;
}
/**
* 把密度转换为像素
*/
public static int dip2px(Context context, float px) {
final float scale = getScreenDensity(context);
return (int) (px * scale + 0.5);
}
弹出的下拉列表可以看作是一个listview,所以在新建一个title_popup.xml
<ListView
android:id="@+id/title_list"
android:layout_width="120dp"
android:layout_height="fill_parent"
android:cacheColorHint="#00000000"
android:divider="@drawable/mm_title_functionframe_line"
android:listSelector="@drawable/title_list_selector"
android:padding="3dp"
android:scrollingCache="false" />
以上就可以实现弹窗功能了