Android 自定义View之倒计时实例代码

/** 
 * 通过selector选择器来改变背景，其中倒计时运行时为android:state_enabled="true"， 
 * 不显示倒计时时为android:state_enabled="false"; 
 * */ 
public class CountDownView extends TextView { 
   
  private long totalMills = 10 * 1000;//倒计时的总时间，根据需要更改这个值 
  private long interval = 1000;//倒计时的时间间隔 
   
  public CountDownView(Context context) { 
    super(context); 
  } 
 
  public CountDownView(Context context, AttributeSet attrs) { 
    super(context, attrs); 
  } 
 
  public CountDownView(Context context, AttributeSet attrs, int defStyle) { 
    super(context, attrs, defStyle); 
  } 
 
  private TimeCount mTimeCount; 
   
  private void startCount(long totalMills, long countDownInterval) { 
    if (mTimeCount == null) 
      mTimeCount = new TimeCount(totalMills, countDownInterval); 
    mTimeCount.start(); 
  } 
   
  public void start(){ 
    defaultText = getText().toString(); 
    startCount(totalMills, interval); 
  } 
 
  public void cancel() { 
    if (mTimeCount != null){ 
      mTimeCount.onFinish(); 
      mTimeCount.cancel(); 
    } 
  } 
 
  String defaultText = "";//获取到在点击之前的文本内容 
 
  class TimeCount extends CountDownTimer { 
 
    public TimeCount(long millisInFuture, long countDownInterval) { 
      super(millisInFuture, countDownInterval); 
    } 
 
    @Override 
    public void onTick(long millisUntilFinished) { 
      setEnabled(false); 
      setText(millisUntilFinished / 1000 + "S"); 
    } 
 
    @Override 
    public void onFinish() { 
      setEnabled(true); 
      setText(defaultText); 
    } 
 
  } 
 
} 

public class MainActivity extends Activity implements OnClickListener { 
 
  private CountDownView mCountDownView; 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
 
    mCountDownView = (CountDownView) findViewById(R.id.tv_1); 
     
    mCountDownView.setOnClickListener(this); 
    findViewById(R.id.tv_2).setOnClickListener(this); 
  } 
 
  int count = 0; 
  DemoThread thread; 
  @Override 
  public void onClick(View v) { 
     
    if(v.getId() == R.id.tv_1){ 
      mCountDownView.start(); 
      thread = new DemoThread(); 
      thread.start(); 
    } else if (v.getId() == R.id.tv_2) { 
      mCountDownView.cancel(); 
      System.out.println("wisely 取消倒计时"); 
    } 
  } 
   
  class DemoThread extends Thread{ 
    @Override 
    public void run() { 
      while (count < 10) { 
        SystemClock.sleep(100); 
        count++; 
        System.out.println("wisely count:" + count); 
      } 
    } 
  } 
} 

<?xml version="1.0" encoding="utf-8"?> 
<selector xmlns:android="http://schemas.android.com/apk/res/android" > 
   
  <item android:state_enabled="true" android:drawable="@color/green"/> 
  <item android:state_enabled="false" android:drawable="@color/red"/> 
 
</selector>