<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:id="@+id/activity_main"  android:layout_width="match_parent"  android:layout_height="match_parent"  tools:context="luoxiang.com.rxcountdown.MainActivity"  android:padding="16dp"  android:orientation="vertical">   <EditText    android:id="@+id/editText"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:hint="請(qǐng)輸入手機(jī)號(hào)碼"     />   <Button    android:id="@+id/btn"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:background="#f97e7e"    android:text="獲取驗(yàn)證碼"    /></LinearLayout>

package luoxiang.com.rxcountdown; import android.graphics.Color;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.View;import android.widget.Button;  import java.util.concurrent.TimeUnit; import rx.Observable;import rx.Observer;import rx.android.schedulers.AndroidSchedulers;import rx.functions.Action0;import rx.functions.Func1;  public class MainActivity extends AppCompatActivity {   private Button mSend;  private static final String TAG = "MainActivity";   @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);     init();   }   private void init() {     mSend = (Button) findViewById(R.id.btn);    mSend.setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View view) {        final int count = 30;         Observable.interval(0, 1, TimeUnit.SECONDS)//設(shè)置0延遲，每隔一秒發(fā)送一條數(shù)據(jù)            .take(count+1) //設(shè)置循環(huán)11次            .map(new Func1<Long, Long>() {              @Override              public Long call(Long aLong) {                return count-aLong; //              }            })            .doOnSubscribe(new Action0() {              @Override              public void call() {                mSend.setEnabled(false);//在發(fā)送數(shù)據(jù)的時(shí)候設(shè)置為不能點(diǎn)擊                 mSend.setBackgroundColor(Color.GRAY);//背景色設(shè)為灰色              }            })             .observeOn(AndroidSchedulers.mainThread())//操作UI主要在UI線程            .subscribe(new Observer<Long>() {              @Override              public void onCompleted() {                Log.d(TAG, "onCompleted: ");                mSend.setText("獲取驗(yàn)證碼");//數(shù)據(jù)發(fā)送完后設(shè)置為原來的文字                mSend.setTextColor(Color.BLACK);                mSend.setBackgroundColor(Color.parseColor("#f97e7e"));//數(shù)據(jù)發(fā)送完后設(shè)置為原來背景色              }               @Override              public void onError(Throwable e) {                e.printStackTrace();              }               @Override              public void onNext(Long aLong) { //接受到一條就是會(huì)操作一次UI                Log.d(TAG, "onNext: "+aLong);                mSend.setText("剩余時(shí)間"+aLong+"秒");                mSend.setEnabled(true);                mSend.setTextColor(Color.WHITE);               }            });      }    });  } }