自定义View向右滑动解锁

//SlideLock类
public class SlideLock extends View {

    private Bitmap jiesuo_bg;
    private Bitmap jiesuo_button;
    private int bg_width;
    private int bg_hight;
    private int block_width;
    private int measuredWidth;
    private int measuredHeight;
    private float currentX;
    private float currentY;
    private int left;
    private int right;
    private float downX;
    private float downY;
    private boolean isOnBlock;
    private OnUnlockListener onUnlockListener;
    public SlideLock(Context context) {
        super(context);
        initView();
    }

    public SlideLock(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        initView();
    }

    public SlideLock(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        initView();
    }
    private void initView(){
        jiesuo_bg = BitmapFactory.decodeResource(getResources(), R.drawable.jiesuo_bg);
        jiesuo_button = BitmapFactory.decodeResource(getResources(), R.drawable.jiesuo_button);
        bg_width = jiesuo_bg.getWidth();
        bg_hight = jiesuo_bg.getHeight();
        block_width = jiesuo_button.getWidth();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawBitmap(jiesuo_bg,measuredWidth/2-bg_width/2,measuredHeight/2-bg_hight/2,null);
        //控制边界
        if (currentX<left){
            currentX=left;
        }else if (currentX>right){
            currentX=right;
        }
        canvas.drawBitmap(jiesuo_button,currentX,currentY,null);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        measuredWidth = getMeasuredWidth();
        measuredHeight = getMeasuredHeight();
        //获取一开始的位置
        currentX = measuredWidth / 2 - bg_width / 2;
        currentY = measuredHeight / 2 - bg_hight / 2;
        left = measuredWidth / 2 - bg_width / 2;
        right = measuredWidth / 2 + bg_width / 2 - block_width;
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()){
            case MotionEvent.ACTION_DOWN:
                //判断手指是否按在了小球上
                downX = event.getX();
                downY = event.getY();
                isOnBlock = isOnBlock(downX, downY);
                if (isOnBlock){
                    Toast.makeText(getContext(),"按到了",Toast.LENGTH_SHORT).show();;
                }
                break;
            case MotionEvent.ACTION_MOVE:
                if (isOnBlock){
                    float moveX = event.getX();
                    currentX = moveX - block_width / 2;
                    invalidate();
                }
                break;
            case MotionEvent.ACTION_UP:
                isOnBlock=false;
                if (currentX<right-5){
                    currentX=left;
                }else {
                     if (onUnlockListener!=null){
                         Toast.makeText(getContext(),"解锁",Toast.LENGTH_SHORT).show();
                         onUnlockListener.setUnlock(true);
                     }
                }
                invalidate();
                break;
        }
        return true;
    }
    private boolean isOnBlock(float downX,float downY){
        float rX= currentX + block_width / 2;
        float rY=currentY+block_width/2;
        double distance = Math.sqrt((downX - rX) * (downX - rX) + (downY - rY) * (downY - rY));
        if (distance<block_width/2){
            return true;
        }
        return false;
    }
    public void setOnUnlockListener(OnUnlockListener onUnlockListener){
        this.onUnlockListener=onUnlockListener;
    }
}



 

public interface OnUnlockListener {
    public void setUnlock(boolean unlock);
}




//主页面

public class MainActivity extends AppCompatActivity {

    private SlideLock slideLock;
    private ImageView img;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        slideLock = (SlideLock) findViewById(R.id.slideLock);
        img = (ImageView) findViewById(R.id.img);
        slideLock.setOnUnlockListener(new OnUnlockListener() {
            @Override
            public void setUnlock(boolean unlock) {
                if (unlock){
                    slideLock.setVisibility(View.GONE);
                    img.setVisibility(View.VISIBLE);
                }
            }
        });
    }
}

<com.example.rightjiesuo.SlideLock
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/slideLock"/>
<ImageView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/img"
    android:src="@drawable/e"
    android:visibility="gone"/>

//GitHub
https://github.com/Zhaolifang1/Rightjiesuo