进度条、拖动条

main.xml文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:orientation="vertical"

    tools:context=".MainActivity" >

    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/progressbar1" />

    <ProgressBar

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/progressbar1"

/>

   <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="@string/progressbar2" />

   <!-- 注：进度条默认为环形的， 假如要定义水平进度条时，需要加上属性  style="?android:attr/progressBarStyleHorizontal-->

    <ProgressBar

        style="?android:attr/progressBarStyleHorizontal"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/progressbar2"

/>

</LinearLayout>

.java 程序

package com.example.progressbardemo;

import java.security.PublicKey;

import android.os.Bundle;

import android.os.Handler;

import android.app.Activity;

import android.view.Menu;

import android.widget.ProgressBar;

public class MainActivity extends Activity {

    private ProgressBar mProgressBar;

    private  int mProgressStatus = 0;

    //创建一个Handler对象

    private Handler mHandler = new Handler();

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        mProgressBar = (ProgressBar) findViewById(R.id.progressbar2);

        //设定进度条的最大值，其将为该进度条显示的基数

        mProgressBar.setMax(1000);

        //新创建一个线程

        new Thread( new Runnable() {

            @Override

            public void run() {

                // TODO Auto-generated method stub

                //循环1000次，不停更新mprogresstatus 的值

                while(mProgressStatus++<1000)

                    //将一个runnable对象添加到消息队列中，并且当执行到该对象时执行run方法

                    mHandler.post(new Runnable() { //自定义

                        @Override

                        public void run() {

                            // TODO Auto-generated method stub

                            //重新设置进度条当前的值

                            mProgressBar.setProgress(mProgressStatus);

});

        }).start();

    @Override

    public 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;

拖动条（SeekBar）

seekbar 是 ProgressBar的一个子类

有几个方法：

SeekBar.getProgress() 获取拖动条当前值

setOnSeekBarChangeListener()方法，处理拖动条值变化事件，把SeekBar.OnSeekBarChangeListener实例作为参数传入

string.xml文件

<?xml version="1.0" encoding="utf-8"?>

<resources>

    <string name="app_name">拖动条实例</string>

    <string name="action_settings">Settings</string>

    <string name="hello_world">Hello world!</string>

    <string name="speed">播放进度</string>

</resources>

main.xml文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:orientation="vertical"

    tools:context=".MainActivity" >

    <TextView

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="@string/speed"

        android:id="@+id/speed"

/>

    <SeekBar

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:id="@+id/seek_bar"

/>

</LinearLayout>

activity.java中文件

   1:  package com.example.seekbardemo;

2:

   3:  import android.R.bool;

   4:  import android.os.Bundle;

   5:  import android.os.Handler;

   6:  import android.app.Activity;

   7:  import android.view.Menu;

   8:  import android.widget.SeekBar;

   9:  import android.widget.TextView;

10:

  11:  public class MainActivity extends Activity {

  12:      private SeekBar seekBar;

  13:      private TextView textView;

  14:      //标记是否需要更新

  15:      private boolean flag = true;

  16:      private Handler handler = new Handler();

17:

  18:      @Override

  19:      protected void onCreate(Bundle savedInstanceState) {

  20:          super.onCreate(savedInstanceState);

  21:          setContentView(R.layout.activity_main);

22:

  23:          seekBar = (SeekBar) findViewById(R.id.seek_bar);

  24:          textView = (TextView) findViewById(R.id.speed);

25:

  26:          //设定拖动条的最大值，其将为该拖动条显示的基数。

  27:          seekBar.setMax(100);

  28:          //该方法为 seekBar 注册一个监听， 当 SeekBar 发生改变时调用参数 l 中的对应方法。

  29:           seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {

30:

  31:              @Override

  32:              public void onStopTrackingTouch(SeekBar seekBar) {

  33:                  // TODO Auto-generated method stub

  34:                  //设置标记需要刷新

  35:                  flag = true;

  36:                  refrech();

37:

  38:              }

39:

  40:              @Override

  41:              public void onStartTrackingTouch(SeekBar seekBar) {

  42:                  // TODO Auto-generated method stub

  43:                  flag = false;

  44:              }

45:

  46:              @Override

  47:              public void onProgressChanged(SeekBar seekBar, int progress,

  48:                      boolean fromUser) {

  49:                  // TODO Auto-generated method stub

  50:                  //更改textView的内容

  51:                  textView.setText("进度为： " + progress + "%");

  52:              }

  53:          });

54:

55:

  56:      }

57:

  58:      protected void refrech() {

  59:          // TODO Auto-generated method stub

  60:          new  Thread(new Runnable() {

61:

  62:              @Override

  63:              public void run() {

  64:                  // TODO Auto-generated method stub

  65:                  while(flag && seekBar.getProgress()<100)

  66:                  {

  67:                      try{

  68:                          //暂停一秒

  69:                          Thread.sleep(1000);

  70:                      }

  71:                          catch (Exception e)

  72:                          {

  73:                              // TODO: handle exception

  74:                              e.printStackTrace();

  75:                          }

  76:                      //将一个 Runnable 对象添加到消息队列当中，

  77:                      //并且当执行到该对象时执行 run()方法

  78:                      handler.post(new Runnable() {

  79:                      public void run() {

  80:                      //重新设置进度条当前的值，加 1

  81:                      seekBar.setProgress(seekBar.getProgress() + 1);

  82:                      }

  83:                      });

84:

  85:                      }

  86:                  }

  87:          }).start();

  88:      }

89:

  90:      @Override

  91:      public boolean onCreateOptionsMenu(Menu menu) {

  92:          // Inflate the menu; this adds items to the action bar if it is present.

  93:          getMenuInflater().inflate(R.menu.main, menu);

  94:          return true;

  95:      }

96:

  97:  }

说明：
当 SeekBarActivity 创建时，为 seekBar 注册监听事件。并且调用 refresh()方法，
自动刷新拖动条的进度值。当拖动条进度值改变时，修改 seekBar 上部 TextView 的内容。

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