学步园

ndroid 在列表List中显示半透明小窗体效果的控件，多的不多直接上代码，要说的都在注释里了：

import com.hiapk.market.R;<br /> import android.content.Context;<br /> import android.graphics.PixelFormat;<br /> import android.os.Handler;<br /> import android.view.LayoutInflater;<br /> import android.view.View;<br /> import android.view.WindowManager;<br /> import android.view.WindowManager.LayoutParams;<br /> import android.widget.TextView; </p> <p>/**<br /> * 窗口中间显示半透明提示框的小组件<br /> * 用法：1. new 2. showPrevLetter(String prevLetter)<br /> * @author LL<br /> *<br /> */<br /> public class PrevLetterDialog {<br /> //窗体消失的延时时间<br /> private static final int DELAYED_HIDEN = 500; </p> <p> // 实现Runnable接口的类<br /> private RemoveWindow mRemoveWindow = new RemoveWindow();<br /> //在Handler里能实现对UI线程的修改<br /> private Handler mHandler;<br /> //窗体管理器<br /> private WindowManager mWindowManager;<br /> //显示在窗体中间半透明的字体框<br /> private TextView mDialogText;<br /> //是否正在显示中<br /> private boolean mShowing;<br /> //是否准备好显示了<br /> private boolean mReady;<br /> //显示在窗体中的字符<br /> private char mPrevLetter = Character.MIN_VALUE; </p> <p> /**<br /> * 注明：context一定要在可见UI中通过getContext()获得，否则会抛异常。<br /> * @param context<br /> */<br /> public PrevLetterDialog(Context context) {<br /> //得到窗体管理器<br /> mWindowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE); </p> <p> //得到布部创建者<br /> LayoutInflater inflate = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);<br /> //得到TextView<br /> mDialogText = (TextView) inflate.inflate(R.layout.list_position, null);<br /> //设TextView为可见<br /> mDialogText.setVisibility(View.INVISIBLE); </p> <p> //通过handler把mDialogText展示出来<br /> mHandler = new Handler();<br /> //要用post可实现在多线程里调用UI线程并改变<br /> mHandler.post(new Runnable() {<br /> public void run() {<br /> mReady = true;<br /> //窗体的布局参数<br /> WindowManager.LayoutParams lp = new WindowManager.LayoutParams(LayoutParams.WRAP_CONTENT,<br /> LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.TYPE_APPLICATION,<br /> WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,<br /> PixelFormat.TRANSLUCENT);<br /> //把TextView添加到窗体中去<br /> mWindowManager.addView(mDialogText, lp);<br /> }<br /> }); </p> <p> } </p> <p> //设置可见性<br /> public void setmReady(boolean mReady) {<br /> this.mReady = mReady;<br /> } </p> <p> /**<br /> * 一般用在onScroll方法中,参数是字符串，不能为空，会取第一个字符显示<br /> * @param prevLetter<br /> */<br /> public void showPrevLetter(String prevLetter) {<br /> if (!mReady) {<br /> return;<br /> }<br /> char firstLetter = prevLetter.charAt(0); </p> <p> if (!mShowing && firstLetter != mPrevLetter) { </p> <p> mShowing = true;<br /> mDialogText.setVisibility(View.VISIBLE); </p> <p> }<br /> //设TextView显示的字体<br /> mDialogText.setText(((Character) firstLetter).toString());<br /> //移除mRemoveWindow实现的Runnable接口类<br /> mHandler.removeCallbacks(mRemoveWindow);<br /> //添加mRemoveWindow实现的Runnable接口类，并设延时<br /> mHandler.postDelayed(mRemoveWindow, DELAYED_HIDEN);<br /> mPrevLetter = firstLetter; </p> <p> } </p> <p> /**<br /> * 实现Runnable接口的类<br /> */<br /> private final class RemoveWindow implements Runnable {<br /> public void run() {<br /> removeWindow();<br /> }<br /> } </p> <p> private void removeWindow() {<br /> if (mShowing) {<br /> mShowing = false;<br /> mDialogText.setVisibility(View.INVISIBLE);<br /> }<br /> } </p> <p>}<br /> 以上是xml文件<br /> view plaincopy to clipboardprint?<br /> <?xml version="1.0" encoding="utf-8"?><br /> <TextView xmlns:android="http://schemas.android.com/apk/res/android"<br /> android:textSize="50sp"<br /> android:textColor="@color/band_common_content"<br /> android:background="@drawable/common_list_title"<br /> android:minWidth="70dip"<br /> android:layout_height="wrap_content"<br /> android:padding="5dip"<br /> android:gravity="center"<br /> />