android开发学习笔记——简单的ProgressBar

ProgressBar显示程序执行的进度，应用比较简单，像复杂的Notification进度条将在以后仔细学习。

本人android的菜鸟，如有错误还望各位大牛不吝赐教！

运行的activity   .java代码如下：

package com.example.progressbar;import android.os.Bundle;import android.app.Activity;import android.view.Menu;import android.view.View;import android.widget.Button;import android.widget.ProgressBar;import android.widget.Toast;public class MainActivity extends Activity {private ProgressBar bar1;private ProgressBar bar2;private Button button1;private int i=0;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);bar1=(ProgressBar)findViewById(R.id.progressBar1);bar2=(ProgressBar)findViewById(R.id.progressBar2);button1=(Button)findViewById(R.id.dowmload);System.out.println(bar1.getMax());System.out.println(bar2.getMax());}//download 绑定下载按钮public void download(View view) {if(i==0){bar1.setVisibility(view.VISIBLE);bar2.setVisibility(view.VISIBLE);}else if (i<100) {bar1.setProgress(i+10);bar2.setSecondaryProgress(i+10);}else {//下载完成之后显示的toastToast toast=Toast.makeText(MainActivity.this,"下载完成",Toast.LENGTH_SHORT);toast.show();}//注意位置i=i+10;}//exitprogrampublic void exitprogram(View view){System.exit(0);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}

layout当中的xml配置文件

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity" >    <ProgressBar        android:id="@+id/progressBar2"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_alignLeft="@+id/progressBar1"        android:layout_below="@+id/progressBar1"        android:layout_marginLeft="105dp"        android:layout_marginTop="34dp"        android:visibility="gone" />    <ProgressBar        android:id="@+id/progressBar1"        style="?android:attr/progressBarStyleHorizontal"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:layout_alignParentTop="true"        android:layout_centerHorizontal="true"        android:layout_marginTop="40dp"        android:visibility="gone" />        <Button            android:id="@+id/dowmload"            android:layout_width="fill_parent"            android:layout_height="wrap_content"            android:layout_alignParentBottom="true"            android:layout_centerHorizontal="true"            android:layout_marginBottom="89dp"            android:onClick="download"            android:text="@string/button1" />        <Button            android:id="@+id/exitprogram"            android:layout_width="fill_parent"            android:layout_height="wrap_content"            android:layout_alignLeft="@+id/dowmload"            android:layout_alignParentBottom="true"            android:layout_marginBottom="45dp"            android:onClick="exitprogram"            android:text="@string/exitbutton" /></RelativeLayout>