Android自定义View实现打字机效果

一、先来看看效果演示

二、实现原理：

这个其实不难实现，通过一个定时器不断调用textview的settext就行了，在settext的时候播放打字的音效。

具体代码如下：

import java.util.timer;
import java.util.timertask;

import android.content.context;
import android.media.mediaplayer;
import android.text.textutils;
import android.util.attributeset;
import android.widget.textview;

import com.uperone.typetextview.r;

/**
 * 模拟打字机效果
 * 
 * */
public class typetextview extends textview {
 private context mcontext = null;
 private mediaplayer mmediaplayer = null;
 private string mshowtextstring = null;
 private timer mtypetimer = null;
 private ontypeviewlistener montypeviewlistener = null;
 private static final int type_time_delay = 80;
 private int mtypetimedelay = type_time_delay; // 打字间隔

 public typetextview(context context, attributeset attrs, int defstyle) {
  super(context, attrs, defstyle);
  inittypetextview( context );
 }

 public typetextview(context context, attributeset attrs) {
  super(context, attrs);
  inittypetextview( context );
 }

 public typetextview(context context) {
  super(context);
  inittypetextview( context );
 }

 public void setontypeviewlistener( ontypeviewlistener ontypeviewlistener ){
  montypeviewlistener = ontypeviewlistener;
 }

 public void start( final string textstring ){
  start( textstring, type_time_delay );
 }

 public void start( final string textstring, final int typetimedelay ){
  if( textutils.isempty( textstring ) || typetimedelay < 0 ){
   return;
  }
  post( new runnable( ) {
   @override
   public void run() {
    mshowtextstring = textstring;
    mtypetimedelay = typetimedelay;
    settext( "" );
    starttypetimer( );
    if( null != montypeviewlistener ){
     montypeviewlistener.ontypestart( );
    }
   }
  });
 }

 public void stop( ){
  stoptypetimer( );
  stopaudio();
 }

 private void inittypetextview( context context ){
  mcontext = context;
 }

 private void starttypetimer( ){
  stoptypetimer( );
  mtypetimer = new timer( );
  mtypetimer.schedule( new typetimertask(), mtypetimedelay );
 }

 private void stoptypetimer( ){
  if( null != mtypetimer ){
   mtypetimer.cancel( );
   mtypetimer = null;
  }
 }

 private void startaudioplayer() {
  stopaudio();
  playaudio( r.raw.type_in );
 }

 private void playaudio( int audioresid ){
  try{
   stopaudio( );
   mmediaplayer = mediaplayer.create( mcontext, audioresid );
   mmediaplayer.start( );
  }catch( exception e ){
   e.printstacktrace();
  }
 }

 private void stopaudio( ){
  if( mmediaplayer != null && mmediaplayer.isplaying( ) ){
   mmediaplayer.stop( );
   mmediaplayer.release( );
   mmediaplayer = null;
  }
 }

 class typetimertask extends timertask{
  @override
  public void run() {
   post(new runnable( ) {
    @override
    public void run() {
     if( gettext( ).tostring( ).length( ) < mshowtextstring.length( ) ){
      settext( mshowtextstring.substring(0, gettext( ).tostring( ).length( ) + 1 ) );
      startaudioplayer();
      starttypetimer( );
     }else{
      stoptypetimer( );
      if( null != montypeviewlistener ){
       montypeviewlistener.ontypeover( );
      }
     }
    }
   });
  }
 }

 public interface ontypeviewlistener{
  public void ontypestart( );
  public void ontypeover( );
 }
}

三、使用说明：

1、在xml文件中定义：

 <com.uperone.typetext.view.typetextview
  android:id="@+id/typetxtid"
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:layout_centervertical="true" />

2、在代码中实例化：

 mtypetextview = ( typetextview )findviewbyid(r.id.typetxtid);
 mtypetextview.setontypeviewlistener( new ontypeviewlistener( ) {
  @override
  public void ontypestart() {
   print( "ontypestart" );
  }

  @override
  public void ontypeover() {
   print( "ontypeover" );
  }
 });

3、调用start方法：

 

mtypetextview.start( test_data );

四、总结

以上就是android自定义view实现打字机效果的全部内容，感兴趣的快快自己动手实践起来，希望本文的内容对大家开发android的时候能有所帮助，如果有疑问可以留言交流。