Android 滑动开关按钮

刚看了一篇博客地址：http://blog.youkuaiyun.com/xiaanming/article/details/8842453

个人技术水平有限，在原基础上整理出自定义控件代码如下：

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

import com.example.swipercheck.R;

@SuppressLint({ "ClickableViewAccessibility", "DrawAllocation" })
public class SwipperView extends View {

	/** 关闭的图片资源 */
	private Drawable mBitmapOpenDrawable;
	/** 打开的图片资源 */
	private Drawable mBitmapCloseDrawable;
	/** 拖拽的图片资源 */
	private Drawable mBitmapSlipDrawable;
	/** 是否在滑动 */
	private boolean isScroll;
	/** 关闭的图片 */
	private Bitmap mBitmapClose;
	/** 打开的图片 */
	private Bitmap mBitmapOpen;
	/** 拖拽的图片 */
	private Bitmap mBitmapSlip;
	/** 自定义属性文件 */
	private int[] mDefStyleAttr=R.styleable.Swipper;
	private float mCurrX;
	private boolean mCurrStatus;

	
	public SwipperView(Context context, AttributeSet attrs, int defStyleAttr) {
		super(context, attrs, defStyleAttr);
		// TODO Auto-generated constructor stub
		TypedArray mTypeArray = context.obtainStyledAttributes(attrs,
				mDefStyleAttr);
		// 获取自定义属性值
		mBitmapCloseDrawable= mTypeArray.getDrawable(
				R.styleable.Swipper_backgroundClose);
		mBitmapOpenDrawable= mTypeArray.getDrawable(
				R.styleable.Swipper_backgroundOpen);
		mBitmapSlipDrawable= mTypeArray.getDrawable(
				R.styleable.Swipper_backgroundSwipper);

		// 获取图片资源
		mBitmapClose = drawableToBitamp(mBitmapCloseDrawable);
		mBitmapOpen= drawableToBitamp(mBitmapOpenDrawable);
		mBitmapSlip= drawableToBitamp(mBitmapSlipDrawable);

		mTypeArray.recycle();
	}

	public SwipperView(Context context, AttributeSet attrs) {
		this(context, attrs, 0);
		// TODO Auto-generated constructor stub
	}

	public SwipperView(Context context) {
		this(context, null);
		// TODO Auto-generated constructor stub
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		// TODO Auto-generated method stub

		mCurrX = event.getX();

		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN:
			isScroll = true;
			break;
		case MotionEvent.ACTION_MOVE:
			break;

		case MotionEvent.ACTION_UP:
			isScroll = false;
			if (mCurrX>= mBitmapClose.getWidth() / 2) {
				// 滑动距离可以滑动过去，当前状态打开
				mCurrX = mBitmapClose.getWidth() - mBitmapSlip.getWidth();
				mCurrStatus = true;
			} else {
				// 滑动距离不够，当前状态关闭
				mCurrX = 0;
				mCurrStatus = false;
			}
			if(mListener != null){
				mListener.onSwipperChange(mCurrStatus);
			}
			break;
		default:
			break;
		}
		invalidate();
		return true;
	}

	@Override
	protected void onDraw(Canvas canvas) {
		// TODO Auto-generated method stub
		super.onDraw(canvas);
		Matrix matrix = new Matrix();
		Paint mPaint = new Paint();
		
		float x = 0;
		if (mCurrX < (mBitmapClose.getWidth() / 2)) {
			canvas.drawBitmap(mBitmapClose, matrix, mPaint);
		} else {
			canvas.drawBitmap(mBitmapOpen, matrix, mPaint);
		}

		if (isScroll) {// 是否是在滑动状态,
			if (mCurrX >= mBitmapClose.getWidth())// 是否划出指定范围,不能让滑块跑到外头,必须做这个判断
				x = mBitmapClose.getWidth() - mBitmapSlip.getWidth() / 2;// 减去滑块1/2的长度
			else
				x = mCurrX - mBitmapSlip.getWidth() / 2;
		} else {
			if (mCurrStatus) {// 根据当前的状态设置滑块的x值
				x = mBitmapClose.getWidth() - mBitmapSlip.getWidth();
			} else {
				x = 0;
			}
		}

		// 对滑块滑动进行异常处理，不能让滑块出界
		if (x < 0) {
			x = 0;
		} else if (x > mBitmapClose.getWidth() - mBitmapSlip.getWidth()) {
			x = mBitmapClose.getWidth() - mBitmapSlip.getWidth();
		}

		// 画出滑块
		canvas.drawBitmap(mBitmapSlip, x, 0, mPaint);

	}

	/**
	 * 监听开关变化接口
	 * 
	 * @author Administrator
	 * 
	 */
	public interface OnSwipperListener {
		void onSwipperChange(boolean isOpen);
	}

	private OnSwipperListener mListener;

	public OnSwipperListener getmListener() {
		return mListener;
	}

	public void setmListener(OnSwipperListener mListener) {
		this.mListener = mListener;
	}

	/**
	 * 设置滑动开关的初始状态，供外部调用
	 * @param checked
	 */
	public void setChecked(boolean checked){
		if(checked){
			mCurrX = mBitmapClose.getWidth();
		}else{
			mCurrX = 0;
		}
		mCurrStatus = checked;
	}


	/***
	 * Bitmap Drawable 转换
	 * @param drawable
	 * @return
	 */
	private Bitmap drawableToBitamp(Drawable drawable)
	{
		 Bitmap mBitmap=null;
		 BitmapDrawable bd = (BitmapDrawable) drawable;
		 mBitmap= bd.getBitmap();
		return mBitmap;
	}

}

attr.xml

<resources>

    <declare-styleable name="Swipper">
        <attr name="backgroundClose" format="color|reference" />
        <attr name="backgroundOpen" format="color|reference" />
        <attr name="backgroundSwipper" format="color|reference" />
    </declare-styleable>

</resources>

备注说明：.9.png图片获取成Drawable不能bitmapDrawable,否则会报错