转自：http://blog.sina.com.cn/s/blog_691051e10101a3by.html
很多时候没有我们需要使用的控件，或者控件并不美观。比如这个滑动开关，这是android之后的版本才提供的控件，新版本并不提供，这个时候就需要我们自定义控件了。
一个2个主要类，OnChangedListener，SlipButton
SlipButton代码如下
package com.appipv6.android.slipbutton;
import com.appipv.onoff.R;
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
{
//当前按钮状态
private boolean nowChoose=false;
//用户是否在滑动
private boolean onSlip=false;
//按下时的X，当时的X
private float downX,nowX;
//打开和关闭状态下的，游标的Rect
private Rect btn_On,btn_Off;
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();
}
public SlipButton(Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
init();
}
private void init()
{
// TODO Auto-generated method stub
bg_on=BitmapFactory.decodeResource(getResources(), R.drawable.on);
bg_off=BitmapFactory.decodeResource(getResources(), R.drawable.off);
slip_btn=BitmapFactory.decodeResource(getResources(), R.drawable.my_btn);
int tmp=bg_off.getWidth()/2;
btn_On=new Rect(tmp, 0, slip_btn.getWidth()+tmp, slip_btn.getHeight());
btn_Off=new Rect(bg_off.getWidth()-tmp-slip_btn.getWidth(), 0, bg_off.getWidth()-tmp, slip_btn.getHeight());
setOnTouchListener(this);
}
@Override
protected void onDraw(Canvas canvas)
{
// TODO Auto-generated method stub
super.onDraw(canvas);
Matrix matrix=new Matrix();
Paint paint=new Paint();
float x;
if(onSlip)
{
if(nowX>=bg_on.getWidth())
{
x=bg_on.getWidth()-slip_btn.getWidth()/2;
}else{
x=nowX-slip_btn.getWidth()/2;
}
}else{
if(nowChoose)
{
x=btn_On.left;
}else{
x=btn_Off.left;
}
}
if(nowX<(bg_on.getWidth()/2))
{
canvas.drawBitmap(bg_off, matrix, paint);
}else{
canvas.drawBitmap(bg_on, matrix, paint);
}
if(x<0)
{
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);
}
public boolean onTouch(View v, MotionEvent event)
{
// TODO Auto-generated method stub
switch (event.getAction())
{
case MotionEvent.ACTION_MOVE:
nowX=event.getX();
break;
case MotionEvent.ACTION_DOWN:
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:
onSlip=false;
boolean lastChoose=nowChoose;
if(event.getX()>=(bg_on.getWidth()/2))
{
nowChoose=true;
}else{
nowChoose=false;
}
if(isChgLsnOn&&(lastChoose!=nowChoose))
{
ChgLsn.OnChanged(nowChoose);
}
break;
default:
break;
}
invalidate();
return true;
}
public void setOnChangeListener(OnChangedListener l)
{
isChgLsnOn=true;
ChgLsn=l;
}
public boolean isNowChoose()
{
return nowChoose;
}
public void setNowChoose(boolean nowChoose)
{
this.nowChoose = nowChoose;
nowX=btn_On.left;
invalidate();
}
}
OnChangedListener代码如下
public interface OnChangedListener
{
abstract void OnChanged(boolean CheckState);
}
主Activity代码如下
package com.appipv.onoff;
import com.appipv6.android.slipbutton.OnChangedListener;
import com.appipv6.android.slipbutton.SlipButton;
import android.app.Activity;
import android.os.Bundle;
import android.widget.Toast;
public class OnOffActivity extends Activity
{
private SlipButton slipButton1;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
SlipButton slipButton = (SlipButton) findViewById(R.id.slipButton1);
slipButton.setNowChoose(true);
slipButton1 = (SlipButton) findViewById(R.id.slipButton2);
slipButton.setOnChangeListener(new OnChangedListener()
{
public void OnChanged(boolean CheckState)
{
// TODO Auto-generated method stub
String s;
if(slipButton1.isNowChoose())
{
s="Button2打开了...";
}else{
s="Button2关闭了...";
}
if (CheckState)
Toast.makeText(OnOffActivity.this, "Button1打开了..."+s,
Toast.LENGTH_SHORT).show();
else
Toast.makeText(OnOffActivity.this, "Button1关闭了..."+s,
Toast.LENGTH_SHORT).show();
}
});
}
}
布局文件代码如下
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="@drawable/back"
>
<com.appipv6.android.slipbutton.SlipButton
android:id="@+id/slipButton1"
android:layout_width="wrap_content"
android:layout_height="49dp" />
<com.appipv6.android.slipbutton.SlipButton
android:id="@+id/slipButton2"
android:layout_width="wrap_content"
android:layout_height="fill_parent" />
</LinearLayout>
