Android 滑动开关控件

效果预览:



SlipButton.java

package com.iaiai.activity;

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;

/**
 * 
 * <p>
 * Title: SlipButton.java
 * </p>
 * <p>
 * E-Mail: [email protected]
 * </p>
 * <p>
 * QQ: 176291935
 * </p>
 * <p>
 * Http: iaiai.iteye.com
 * </p>
 * <p>
 * Create time: 2012-9-28 下午4:33:54
 * </p>
 * 
 * @author 丸子
 * @version 0.0.1
 */
public class SlipButton extends View implements OnTouchListener {
	public interface OnChangedListener {
		abstract void OnChanged(String strName, boolean CheckState);
	}

	private String strName;
	private boolean enabled = true;
	public boolean flag = false;// 设置初始化状态
	public 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
	public float DownX = 0f, NowX = 0f;// 按下时的x,当前的x,NowX>100时为ON背景,反之为OFF背景
	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);
		init();
	}

	public SlipButton(Context context, AttributeSet attrs) {
		super(context, attrs);
		init();
	}

	public void setChecked(boolean fl) {
		if (fl) {
			flag = true;
			NowChoose = true;
			NowX = 80;
		} else {
			flag = false;
			NowChoose = false;
			NowX = 0;
		}
	}

	public void setEnabled(boolean b) {
		if (b) {
			enabled = true;
		} else {
			enabled = false;
		}
	}

	private void init() {// 初始化
		// 载入图片资源
		bg_on = BitmapFactory.decodeResource(getResources(), R.drawable.on_btn);
		bg_off = BitmapFactory.decodeResource(getResources(), R.drawable.off_btn);
		slip_btn = BitmapFactory.decodeResource(getResources(), R.drawable.white_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
		super.onDraw(canvas);
		Matrix matrix = new Matrix();
		Paint paint = new Paint();
		float x;
		{
			if (flag) {
				NowX = 80;
				flag = false;
			}// bg_on.getWidth()=71
			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.
		}
	}

	public boolean onTouch(View v, MotionEvent event) {
		if (!enabled) {
			return false;
		}
		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(strName, NowChoose);
			break;
		default:

		}
		invalidate();// 重画控件
		return true;
	}

	public void SetOnChangedListener(String name, OnChangedListener l) {// 设置监听器,当状态修改的时候
		strName = name;
		isChgLsnOn = true;
		ChgLsn = l;
	}
}

MainActivity.java

package com.iaiai.activity;

import android.app.Activity;
import android.os.Bundle;
import android.widget.Toast;

/**
 * 
 * <p>
 * Title: MainActivity.java
 * </p>
 * <p>
 * E-Mail: [email protected]
 * </p>
 * <p>
 * QQ: 176291935
 * </p>
 * <p>
 * Http: iaiai.iteye.com
 * </p>
 * <p>
 * Create time: 2012-9-28 下午4:33:54
 * </p>
 * 
 * @author 丸子
 * @version 0.0.1
 */
public class MainActivity extends Activity implements SlipButton.OnChangedListener {
	SlipButton button;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		button = (SlipButton) findViewById(R.id.slipButton);
		button.SetOnChangedListener("the one", this);

		// button.setEnabled(false);//设置button不可用
		button.setChecked(true);// 设置button的初始化状态为打开
	}

	@Override
	public void OnChanged(String strName, boolean CheckState) {
		if (CheckState) {
			Toast.makeText(MainActivity.this, strName + " is opened!", Toast.LENGTH_LONG).show();
		} else {
			Toast.makeText(MainActivity.this, strName + " is closed!", Toast.LENGTH_LONG).show();
		}
	}

}

下面是用到的三张图片: