Android 在列表List中顯示半透明小表單效果的控制項

 

想實現圖中這樣中間有半透明表單的效果嗎？

Android 在列表List中顯示半透明小表單效果的控制項，多的不多直接上代碼，要說的都在注釋裡了：

 

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 /> * 視窗中間顯示半透明提示框的小工具<br /> * 用法：1. new 2. showPrevLetter(String prevLetter)<br /> * @author LL<br /> *<br /> */<br />public class PrevLetterDialog {<br />//表單消失的延時時間<br />private static final int DELAYED_HIDEN = 500;</p><p>// 實現Runnable介面的類<br />private RemoveWindow mRemoveWindow = new RemoveWindow();<br />//在Handler裡能實現對UI線程的修改<br />private Handler mHandler;<br />//表單管理器<br />private WindowManager mWindowManager;<br />//顯示在表單中間半透明的字型框<br />private TextView mDialogText;<br />//是否正在顯示中<br />private boolean mShowing;<br />//是否準備好顯示了<br />private boolean mReady;<br />//顯示在表單中的字元<br />private char mPrevLetter = Character.MIN_VALUE;</p><p>/**<br /> * 註明：context一定要在可見UI中通過getContext()獲得，否則會拋異常。<br /> * @param context<br /> */<br />public PrevLetterDialog(Context context) {<br />//得到表單管理器<br />mWindowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);</p><p>//得到布部建立者<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 />//設TextView為可見<br />mDialogText.setVisibility(View.INVISIBLE);</p><p>//通過handler把mDialogText展示出來<br />mHandler = new Handler();<br />//要用post可實現在多線程裡調用UI線程並改變<br />mHandler.post(new Runnable() {<br />public void run() {<br />mReady = true;<br />//表單的布局參數<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添加到表單中去<br />mWindowManager.addView(mDialogText, lp);<br />}<br />});</p><p>}</p><p>//設定可見度<br />public void setmReady(boolean mReady) {<br />this.mReady = mReady;<br />}</p><p>/**<br /> * 一般用在onScroll方法中,參數是字串，不可為空，會取第一個字元顯示<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 />//設TextView顯示的字型<br />mDialogText.setText(((Character) firstLetter).toString());<br />//移除mRemoveWindow實現的Runnable介面類<br />mHandler.removeCallbacks(mRemoveWindow);<br />//添加mRemoveWindow實現的Runnable介面類，並設延時<br />mHandler.postDelayed(mRemoveWindow, DELAYED_HIDEN);<br />mPrevLetter = firstLetter;</p><p>}</p><p>/**<br /> * 實現Runnable介面的類<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>}

 以上是xml檔案

 

<?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 />/>