Android 让你的SeekBar 也支持长按事件

it2022-05-09  29

 SeekBar 本身有就是一个View 对象,既然是View 对象那也证明它有setOnLongClickListener 事件,众所周知,这个事件是让一个View 对象拥有长按功能,进而达到我们想要实现的操作。

  为SeekBar 添加长按事件监听如下:

 

    SeekBar.setOnLongClickListener( new  OnLongClickListener() {                        @Override             public   boolean  onLongClick(View v) {                 //  TODO Auto-generated method stub                  return   false ;            }        });

 

那么,我们来试试,它是否可以成立 ,为它添加一个Toast :

 

Toast.makeText(ttActivty. this " fda " 100 ).show();

 

一般来说,我们运行项目,然后长按SeekBar 即能够把Toast Show 出来。那么试一下吧,试了之后结果很让人费解,因为我们知道SeekBar 继承自AbsSeekBar 而AbsSeekBar 又是继承自ProgressBar ,而ProgressBar 的长按事件是可行的,可是这里我们同样的操作却得不到效果,Toast 并不能像我们如期想像的一样显示出来。那是不是就是说SeekBar 不支持长按事件呢?这点我也不好下定论,总之我们为其他同样的View 对象的操作是可行的。好了,既然SeekBar 可能不支持长按事件,那我们就为它模拟一个长按事件,模拟思路如下:

1、继承SeekBar 重写内部的事件和方法2、实现一个线程,当在规定的时间内停住即认为其是一个长按动作3、实现长按事件的接口函数4、并为重写的SeekBar 添加自己的OnSeekBarChangeListener 监听事件

具体操作看如下:

 

1、继承SeekBar 重写内部的事件和方法

代码如下:

 

public   class  seekBarDemo  extends  SeekBar  implements  OnTouchListener

 

 

2、实现一个线程,当在规定的时间内停住即认为其是一个长按动作

 

 这里实现一个自己的Runable 对象,向Handler 对象发送消息,代码如下:

 

/**          * 为runable 赋值          */         runable  =   new  Runnable() {            @Override             public   void  run() {                 //  TODO Auto-generated method stub                  do  {                    i ++ ;                     try  {                        Thread.sleep( 400 );                        Message msg  =  hand.obtainMessage();                        msg.arg1  =  i;                        msg.sendToTarget();                    }  catch  (InterruptedException e) {                         //  TODO Auto-generated catch block                         e.printStackTrace();                    }                }  while  (isStop);            }        };

 

之后实现一个handler 对象用来设置该重写View 具有的长按事件

3、实现长按事件的接口函数

/**      * 获取一个handler 对象     *  @param  0代表onTouch 1代表onChange     *  @param  视图对象     *  @param  进度     *  @return  返回一个handler对象      */      public  Handler getHandler( final   int  j,  final  View v,  final   int  progress) {        Handler h  =   new  Handler() {            @Override             public   void  handleMessage(Message msg) {                 //  TODO Auto-generated method stub                  switch  (j) {                 case   0 :                     if  (msg.arg1  ==   3 ) {                         if  (longClick  !=   null ) {                            longClick.onLongClick(v);                        }                    }                     break ;                 case   1 :                     if  (msg.arg1  ==   1 ) {                        pp  =  progress;                    }                     if  (msg.arg1  ==   2 ) {                         if  (pp  !=  progress) {                            i  =   0 ;                        }                    }                     if  (msg.arg1  ==   3 ) {                        i  =   0 ;                         if  (pp  ==  progress) {                             if  (longClick  !=   null ) {                                longClick.onLongClick(seekBarDemo. this );                            }                        }                    }                     break ;                }                 super .handleMessage(msg);            }        };         return  h;    }

 

 

4、并为重写的SeekBar 添加自己的OnSeekBarChangeListener 监听事件

这里我们首先定义一个onChange 接口 ,接口中有三未实现的方法,分别代表SeekBar 的三种状态

 

/**      * 进度改变接口     *  @author  terry     *      */      public   interface  onChange {         public   void  onStopTrackingTouch(seekBarDemo seekBar);         public   void  onStartTrackingTouch(seekBarDemo seekBar);         public   void  onProgressChanged(seekBarDemo seekBar,  int  progress,                 boolean  fromUser);    }

 

实现接口函数:

 

this .setOnSeekBarChangeListener( new  OnSeekBarChangeListener() {            @Override             public   void  onStopTrackingTouch(SeekBar seekBar) {                 //  TODO Auto-generated method stub                  if  (SeekBarChange  !=   null ) {                    SeekBarChange.onStopTrackingTouch(seekBarDemo. this );                }            }            @Override             public   void  onStartTrackingTouch(SeekBar seekBar) {                 //  TODO Auto-generated method stub                  if  (SeekBarChange  !=   null ) {                    SeekBarChange.onStartTrackingTouch(seekBarDemo. this );                }            }            @Override             public   void  onProgressChanged( final  SeekBar seekBar,                     final   int  progress,  boolean  fromUser) {                 if  (SeekBarChange  !=   null ) {                    SeekBarChange.onProgressChanged(seekBarDemo. this , progress,                            fromUser);                }                hand  =  getHandler( 1 , seekBarDemo. this , progress);            }        });

 

 

 

完整的参考代码如下:

 

package  org.lytsing.android.qzoneloading; import  android.content.Context; import  android.os.Handler; import  android.os.Message; import  android.util.AttributeSet; import  android.view.MotionEvent; import  android.view.View; import  android.view.View.OnTouchListener; import  android.widget.SeekBar; public   class  seekBarDemo  extends  SeekBar  implements  OnTouchListener {     private  onLong longClick;     /**      * 长按接口     *  @author  terry     *      */      public   interface  onLong {         public   boolean  onLongClick(View v);    }     private  onChange SeekBarChange;     /**      * 进度改变接口     *  @author  terry     *      */      public   interface  onChange {         public   void  onStopTrackingTouch(seekBarDemo seekBar);         public   void  onStartTrackingTouch(seekBarDemo seekBar);         public   void  onProgressChanged(seekBarDemo seekBar,  int  progress,                 boolean  fromUser);    }          private  Handler hand;     private  Runnable runable;     private  Thread th;     public   static   int  i  =   0 ;     private   boolean  isStop  =   false ;     public   static   int  pp  =   0 ;     public   int  index  =   0 ;     public  seekBarDemo(Context context) {         this (context,  null );         //  TODO Auto-generated constructor stub     }     public  seekBarDemo(Context context, AttributeSet attrs) {         super (context, attrs);         this .setOnTouchListener( this );         this .setOnSeekBarChangeListener( new  OnSeekBarChangeListener() {            @Override             public   void  onStopTrackingTouch(SeekBar seekBar) {                 //  TODO Auto-generated method stub                  if  (SeekBarChange  !=   null ) {                    SeekBarChange.onStopTrackingTouch(seekBarDemo. this );                }            }            @Override             public   void  onStartTrackingTouch(SeekBar seekBar) {                 //  TODO Auto-generated method stub                  if  (SeekBarChange  !=   null ) {                    SeekBarChange.onStartTrackingTouch(seekBarDemo. this );                }            }            @Override             public   void  onProgressChanged( final  SeekBar seekBar,                     final   int  progress,  boolean  fromUser) {                 if  (SeekBarChange  !=   null ) {                    SeekBarChange.onProgressChanged(seekBarDemo. this , progress,                            fromUser);                }                hand  =  getHandler( 1 , seekBarDemo. this , progress);            }        });         /**          * 为runable 赋值          */         runable  =   new  Runnable() {            @Override             public   void  run() {                 //  TODO Auto-generated method stub                  do  {                    i ++ ;                     try  {                        Thread.sleep( 400 );                        Message msg  =  hand.obtainMessage();                        msg.arg1  =  i;                        msg.sendToTarget();                    }  catch  (InterruptedException e) {                         //  TODO Auto-generated catch block                         e.printStackTrace();                    }                }  while  (isStop);            }        };    }     /**      * 获取一个handler 对象     *  @param  0代表onTouch 1代表onChange     *  @param  视图对象     *  @param  进度     *  @return  返回一个handler对象      */      public  Handler getHandler( final   int  j,  final  View v,  final   int  progress) {        Handler h  =   new  Handler() {            @Override             public   void  handleMessage(Message msg) {                 //  TODO Auto-generated method stub                  switch  (j) {                 case   0 :                     if  (msg.arg1  ==   3 ) {                         if  (longClick  !=   null ) {                            longClick.onLongClick(v);                        }                    }                     break ;                 case   1 :                     if  (msg.arg1  ==   1 ) {                        pp  =  progress;                    }                     if  (msg.arg1  ==   2 ) {                         if  (pp  !=  progress) {                            i  =   0 ;                        }                    }                     if  (msg.arg1  ==   3 ) {                        i  =   0 ;                         if  (pp  ==  progress) {                             if  (longClick  !=   null ) {                                longClick.onLongClick(seekBarDemo. this );                            }                        }                    }                     break ;                }                 super .handleMessage(msg);            }        };         return  h;    }     /**      * 设置长按事件     *  @param  longClick      */      public   void  setOnLongSeekBarClick(onLong longClick) {         this .longClick  =  longClick;    }     /**      * 设置进度改变事件     *  @param  change      */      public   void  setOnSeekBarChange(onChange change) {         this .SeekBarChange  =  change;    }    @Override     public   boolean  onTouch( final  View v, MotionEvent event) {         //  TODO Auto-generated method stub          switch  (event.getAction()) {         case  MotionEvent.ACTION_DOWN:            isStop  =   true ;            th  =   new  Thread(runable);            th.start();            i  =   0 ;            hand  =  getHandler( 0 , v,  0 );             break ;         case  MotionEvent.ACTION_UP:            isStop  =   false ;             break ;        }         return   false ;    }}

 

在布局的XML可以如下定义:

 

< org.lytsing.android.qzoneloading.seekBarDemo         android:max ="200"  android:id ="@+id/seek"  android:layout_width ="fill_parent"         android:layout_height ="wrap_content" >      </ org.lytsing.android.qzoneloading.seekBarDemo >

 

 

功能至此完成,在前台可以像我们之前使用SeekBar 一样使用,功能一样,大家也可以根据自己的需求再另行扩展。这里给出的只是一个思路。

转载于:https://www.cnblogs.com/TerryBlog/archive/2010/08/31/1813481.html

相关资源:Android 自定义按钮点击事件和长按事件对比

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