android 拖动按钮

引用:http://blog.sina.com.cn/s/blog_80723de80100vqln.html

首先效果图:


然后是分别建立三个文件,第一个是main.class,第二个是SlipButton.class,第三个是 onchangeListener.class

main.class

import Android.app.Activity;  
import Android.os.Bundle;  
import Android.widget.Toast;  
  
public class Main extends Activity implements OnChangedListener {  
      
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  
          
        SlipButton myBtn =(SlipButton) findViewById(R.id.slipBtn);//获得指定控件   
        myBtn.SetOnChangedListener(this);//为控件设置监听器   
    }  
  
    @Override  
    public void OnChanged(boolean CheckState) {//当按钮状态被改变时   
        // TODO Auto-generated method stub   
        if(CheckState)  
            Toast.makeText(this,"打开了..." , Toast.LENGTH_SHORT).show();  
        else  
            Toast.makeText(this,"关闭了..." , Toast.LENGTH_SHORT).show();  
    }  

SlipButton.class

import Android.content.Context;  
import Android.graphics.Bitmap;  
import Android.graphics.BitmapFactory;  
import Android.graphics.Canvas;  
import Android.graphics.Matrix;  
import Android.graphics.Paint;  
import Android.graphics.Rect;  
import Android.util.AttributeSet;  
import Android.view.MotionEvent;  
import Android.view.View;  
import Android.view.View.OnTouchListener;  
  
public class SlipButton extends View implements OnTouchListener{  
  
    private boolean NowChoose = false;//记录当前按钮是否打开,true为打开,flase为关闭   
    private boolean OnSlip = false;//记录用户是否在滑动的变量   
    private float DownX,NowX;//按下时的x,当前的x,   
    private Rect Btn_On,Btn_Off;//打开和关闭状态下,游标的Rect   
      
    private boolean isChgLsnOn = false;  
    private OnChangedListener ChgLsn;  
      
    private Bitmap bg_on,bg_off,slip_btn;  
      
    public SlipButton(Context context) {  
        super(context);  
        // TODO Auto-generated constructor stub   
        init();  
    }  
  
    public SlipButton(Context context, AttributeSet attrs) {  
        super(context, attrs);  
        // TODO Auto-generated constructor stub   
        init();  
    }  
  
    private void init(){//初始化   
        //载入图片资源   
        bg_on = BitmapFactory.decodeResource(getResources(), R.drawable.slip_bg_on);  
        bg_off = BitmapFactory.decodeResource(getResources(), R.drawable.slip_bg_off);  
        slip_btn = BitmapFactory.decodeResource(getResources(), R.drawable.slip_btn);  
        //获得需要的Rect数据   
        Btn_On = new Rect(0,0,slip_btn.getWidth(),slip_btn.getHeight());  
        Btn_Off = new Rect(  
                bg_off.getWidth()-slip_btn.getWidth(),  
                0,  
                bg_off.getWidth(),  
                slip_btn.getHeight());  
        setOnTouchListener(this);//设置监听器,也可以直接复写OnTouchEvent   
    }  
      
    @Override  
    protected void onDraw(Canvas canvas) {//绘图函数   
        // TODO Auto-generated method stub   
        super.onDraw(canvas);  
        Matrix matrix = new Matrix();  
        Paint paint = new Paint();  
        float x;  
          
        {  
            if(NowX<(bg_on.getWidth()/2))//滑动到前半段与后半段的背景不同,在此做判断   
                canvas.drawBitmap(bg_off,matrix, paint);//画出关闭时的背景   
            else  
                canvas.drawBitmap(bg_on,matrix, paint);//画出打开时的背景   
              
            if(OnSlip)//是否是在滑动状态,   
            {  
                if(NowX >= bg_on.getWidth())//是否划出指定范围,不能让游标跑到外头,必须做这个判断   
                    x = bg_on.getWidth()-slip_btn.getWidth()/2;//减去游标1/2的长度...   
                else  
                    x = NowX - slip_btn.getWidth()/2;  
            }else{//非滑动状态   
                if(NowChoose)//根据现在的开关状态设置画游标的位置   
                    x = Btn_Off.left;  
                else  
                    x = Btn_On.left;  
            }  
        if(x<0)//对游标位置进行异常判断...   
            x = 0;  
        else if(x>bg_on.getWidth()-slip_btn.getWidth())  
            x = bg_on.getWidth()-slip_btn.getWidth();  
        canvas.drawBitmap(slip_btn,x, 0, paint);//画出游标.   
        }  
    }  
  
  
    @Override  
    public boolean onTouch(View v, MotionEvent event) {  
        // TODO Auto-generated method stub   
        switch(event.getAction())//根据动作来执行代码   
        {  
        case MotionEvent.ACTION_MOVE://滑动   
            NowX = event.getX();  
            break;  
        case MotionEvent.ACTION_DOWN://按下   
        if(event.getX()>bg_on.getWidth()||event.getY()>bg_on.getHeight())  
            return false;  
            OnSlip = true;  
            DownX = event.getX();  
            NowX = DownX;  
            break;  
        case MotionEvent.ACTION_UP://松开   
            OnSlip = false;  
            boolean LastChoose = NowChoose;  
            if(event.getX()>=(bg_on.getWidth()/2))  
                NowChoose = true;  
            else  
                NowChoose = false;  
            if(isChgLsnOn&&(LastChoose!=NowChoose))//如果设置了监听器,就调用其方法..   
                ChgLsn.OnChanged(NowChoose);  
            break;  
        default:  
          
        }  
        invalidate();//重画控件   
        return true;  
    }  
      
    public void SetOnChangedListener(OnChangedListener l){//设置监听器,当状态修改的时候   
        isChgLsnOn = true;  
        ChgLsn = l;  
    }  
      

onchangeListener.class

package CMD100.demo.slipButton;  
  
public interface OnChangedListener {  
    abstract void OnChanged(boolean CheckState);  

main.xml代码

<?xml version="1.0" encoding="utf-8"?>  
<LinearLayout xmlns:Android="http://schemas.android.com/apk/res/android"  
    Android:orientation="vertical"  
    Android:layout_width="fill_parent"  
    Android:layout_height="fill_parent"  
    >  
<TextView    
    Android:layout_width="fill_parent"   
    Android:layout_height="wrap_content"   
    Android:text="@string/hello"  
    />  
<LinearLayout  
    Android:orientation = "horizontal"  
    Android:layout_width = "fill_parent"  
    Android:layout_height = "wrap_content"  
    Android:background = "#ff0000"  
    >  
    <TextView  
        Android:text = "测试:"  
        Android:layout_width = "wrap_content"  
        Android:layout_height = "wrap_content"  
        />  
    <CMD100.demo.slipButton.SlipButton  
        Android:id = "@+id/slipBtn"  
        Android:layout_width="wrap_content"   
        Android:layout_height="wrap_content"  
        Android:layout_marginLeft = "10sp"   
    />  
      
</LinearLayout>  
</LinearLayout> 

注意:在xml里头要放置的位置

<[包名].SlipButton
        Android:id = "@+id/slipBtn"
        Android:layout_width="wrap_content"
        Android:layout_height="wrap_content"
        />

然后可以像其他控件一样使用了...

SlipButton myBtn =(SlipButton) findViewById(R.id.slipBtn);
myBtn.SetOnChangedListener(...);


本篇文章来源于 Linux公社网站(www.linuxidc.com)  原文链接:http://www.linuxidc.com/Linux/2011-09/43213.htm

posted @ 2012-08-04 14:57  镇水古月  阅读(346)  评论(0编辑  收藏  举报