大家好，今天給大家講一下Android中ProgressBar的使用，這個(gè)控件在開發(fā)中還是經(jīng)常用到的，比如用戶瀏覽網(wǎng)頁(yè)的時(shí)候，中間肯定有個(gè) 傳輸過(guò)程，所以用進(jìn)度條讓用戶耐心等待。再比如我在Android Market下載應(yīng)用，它也會(huì)有進(jìn)度條顯示下載進(jìn)度。我為什么要舉這兩個(gè)例子呢，是因?yàn)樗鼈兎謩e是圓形進(jìn)度條和長(zhǎng)形進(jìn)度條的代表。如下面兩張圖：

圖1.UC瀏覽網(wǎng)頁(yè)圓形進(jìn)度條效果。

圖2.Google Market應(yīng)用下載長(zhǎng)形進(jìn)度條效果.

下面我們看一下兩都皆有之的Android自帶的瀏覽器的效果圖如下:

為了讓大家更容易理解我將簡(jiǎn)單寫一個(gè)Demo，大家可以按照我的步驟一步一步來(lái)。

第一步：新建一個(gè)Android工程命名為ProgressBarDemo.

第二步:修改main.xml代碼如下(圓形進(jìn)度條和長(zhǎng)形進(jìn)度條這里樣式不同用系統(tǒng)自帶的):

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Welcome to Mr Wei's blog" /> <ProgressBar android:id="@+id/rectangleProgressBar" style="?android:attr/progressBarStyleHorizontal" mce_style="?android:attr/progressBarStyleHorizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:visibility="gone" /> <ProgressBar android:id="@+id/circleProgressBar" style="?android:attr/progressBarStyleLarge" mce_style="?android:attr/progressBarStyleLarge" android:layout_width="wrap_content" android:layout_height="wrap_content" android:visibility="gone" /> <Button android:id="@+id/button" android:text="Show ProgressBar" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout>

第三步:修改ProgressBarDemo.java代碼如下(如果這里有對(duì)Handler和Message不明白的地方可以去Android 高 手進(jìn)階教程（九） 看下這個(gè)教程):

package com.tutor.progress; import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.view.View; import android.widget.Button; import android.widget.ProgressBar; public class ProgressBarDemo extends Activity { private ProgressBar rectangleProgressBar,circleProgressBar; private Button mButton; protected static final int STOP = 0x10000; protected static final int NEXT = 0x10001; private int iCount = 0; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //findView By id rectangleProgressBar = (ProgressBar)findViewById(R.id.rectangleProgressBar); circleProgressBar = (ProgressBar)findViewById(R.id.circleProgressBar); mButton = (Button)findViewById(R.id.button); rectangleProgressBar.setIndeterminate(false); circleProgressBar.setIndeterminate(false); mButton.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { rectangleProgressBar.setVisibility(View.VISIBLE); circleProgressBar.setVisibility(View.VISIBLE); rectangleProgressBar.setMax(100); rectangleProgressBar.setProgress(0); circleProgressBar.setProgress(0); //創(chuàng)建一個(gè)線程,每秒步長(zhǎng)為5增加,到100%時(shí)停止 Thread mThread = new Thread(new Runnable() { public void run() { for(int i=0 ; i < 20; i++){ try{ iCount = (i + 1) * 5; Thread.sleep(1000); if(i == 19){ Message msg = new Message(); msg.what = STOP; mHandler.sendMessage(msg); break; }else{ Message msg = new Message(); msg.what = NEXT; mHandler.sendMessage(msg); } }catch (Exception e) { e.printStackTrace(); } } } }); mThread.start(); } }); } //定義一個(gè)Handler private Handler mHandler = new Handler(){ public void handleMessage(Message msg){ switch (msg.what) { case STOP: rectangleProgressBar.setVisibility(View.GONE); circleProgressBar.setVisibility(View.GONE); Thread.currentThread().interrupt(); break; case NEXT: if(!Thread.currentThread().isInterrupted()){ rectangleProgressBar.setProgress(iCount); circleProgressBar.setProgress(iCount); } break; } } }; }

第四步：運(yùn)行上述工程，效果如下圖:

OK,今天就先到這里，希望對(duì)大家有所幫助，大家多留言。謝謝大家 ~

Android 基礎(chǔ)教程之-------Android ProgressBar的使用!