android 滚动样式性别选择器简单实现

首先，自定义PickView

public class PickView extends View{    public static final String TAG = "PickerView";    /**     * text之间间距和minTextSize之比     */    public static final float MARGIN_ALPHA = 2.8f;    /**     * 自动回滚到中间的速度     */    public static final float SPEED = 2;    private List mDataList;    /**     * 选中的位置，这个位置是mDataList的中心位置，一直不变     */    private int mCurrentSelected;    private Paint mPaint;    private float mMaxTextSize = 80;    private float mMinTextSize = 40;    private float mMaxTextAlpha = 255;    private float mMinTextAlpha = 120;    private int mColorText = 0x333333;    private int mViewHeight;    private int mViewWidth;    private float mLastDownY;    /**     * 滑动的距离     */    private float mMoveLen = 0;    private boolean isInit = false;    private onSelectListener mSelectListener;    private Timer timer;    private MyTimerTask mTask;    Handler updateHandler = new Handler()    {        @Override        public void handleMessage(Message msg)        {            if (Math.abs(mMoveLen) < SPEED)            {                mMoveLen = 0;                if (mTask != null)                {                    mTask.cancel();                    mTask = null;                    performSelect();                }            } else                // 这里mMoveLen / Math.abs(mMoveLen)是为了保有mMoveLen的正负号，以实现上滚或下滚                mMoveLen = mMoveLen - mMoveLen / Math.abs(mMoveLen) * SPEED;            invalidate();        }    };    public PickView(Context context)    {        super(context);        init();    }    public PickView(Context context, AttributeSet attrs)    {        super(context, attrs);        init();    }    public void setOnSelectListener(onSelectListener listener)    {        mSelectListener = listener;    }    private void performSelect()    {        if (mSelectListener != null)            mSelectListener.onSelect(mDataList.get(mCurrentSelected));    }    public void setData(List datas)    {        mDataList = datas;        mCurrentSelected = datas.size() / 2;        invalidate();    }    public void setSelected(int selected)    {        mCurrentSelected = selected;    }    private void moveHeadToTail()    {        String head = mDataList.get(0);        mDataList.remove(0);        mDataList.add(head);    }    private void moveTailToHead()    {        String tail = mDataList.get(mDataList.size() - 1);        mDataList.remove(mDataList.size() - 1);        mDataList.add(0, tail);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)    {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);        mViewHeight = getMeasuredHeight();        mViewWidth = getMeasuredWidth();        // 按照View的高度计算字体大小        mMaxTextSize = mViewHeight / 4.0f;        mMinTextSize = mMaxTextSize / 2f;        isInit = true;        invalidate();    }    private void init()    {        timer = new Timer();        mDataList = new ArrayList();        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);        mPaint.setStyle(Paint.Style.FILL);        mPaint.setTextAlign(Paint.Align.CENTER);        mPaint.setColor(mColorText);    }    @Override    protected void onDraw(Canvas canvas)    {        super.onDraw(canvas);        // 根据index绘制view        if (isInit)            drawData(canvas);    }    private void drawData(Canvas canvas)    {        // 先绘制选中的text再往上往下绘制其余的text        float scale = parabola(mViewHeight / 4.0f, mMoveLen);        float size = (mMaxTextSize - mMinTextSize) * scale + mMinTextSize;        mPaint.setTextSize(size);        mPaint.setAlpha((int) ((mMaxTextAlpha - mMinTextAlpha) * scale + mMinTextAlpha));        // text居中绘制，注意baseline的计算才能达到居中，y值是text中心坐标        float x = (float) (mViewWidth / 2.0);        float y = (float) (mViewHeight / 2.0 + mMoveLen);        Paint.FontMetricsInt fmi = mPaint.getFontMetricsInt();        float baseline = (float) (y - (fmi.bottom / 2.0 + fmi.top / 2.0));        canvas.drawText(mDataList.get(mCurrentSelected), x, baseline, mPaint);        // 绘制上方data        for (int i = 1; (mCurrentSelected - i) >= 0; i++)        {            drawOtherText(canvas, i, -1);        }        // 绘制下方data        for (int i = 1; (mCurrentSelected + i) < mDataList.size(); i++)        {            drawOtherText(canvas, i, 1);        }    }    /**     * @param canvas     * @param position     *            距离mCurrentSelected的差值     * @param type     *            1表示向下绘制，-1表示向上绘制     */    private void drawOtherText(Canvas canvas, int position, int type)    {        float d = (float) (MARGIN_ALPHA * mMinTextSize * position + type                * mMoveLen);        float scale = parabola(mViewHeight / 4.0f, d);        float size = (mMaxTextSize - mMinTextSize) * scale + mMinTextSize;        mPaint.setTextSize(size);        mPaint.setAlpha((int) ((mMaxTextAlpha - mMinTextAlpha) * scale + mMinTextAlpha));        float y = (float) (mViewHeight / 2.0 + type * d);        Paint.FontMetricsInt fmi = mPaint.getFontMetricsInt();        float baseline = (float) (y - (fmi.bottom / 2.0 + fmi.top / 2.0));        canvas.drawText(mDataList.get(mCurrentSelected + type * position),                (float) (mViewWidth / 2.0), baseline, mPaint);    }    /**     * 抛物线     *     * @param zero     *            零点坐标     * @param x     *            偏移量     * @return scale     */    private float parabola(float zero, float x)    {        float f = (float) (1 - Math.pow(x / zero, 2));        return f < 0 ? 0 : f;    }    @Override    public boolean onTouchEvent(MotionEvent event)    {        switch (event.getActionMasked())        {            case MotionEvent.ACTION_DOWN:                doDown(event);                break;            case MotionEvent.ACTION_MOVE:                doMove(event);                break;            case MotionEvent.ACTION_UP:                doUp(event);                break;        }        return true;    }    private void doDown(MotionEvent event)    {        if (mTask != null)        {            mTask.cancel();            mTask = null;        }        mLastDownY = event.getY();    }    private void doMove(MotionEvent event)    {        mMoveLen += (event.getY() - mLastDownY);        if (mMoveLen > MARGIN_ALPHA * mMinTextSize / 2)        {            // 往下滑超过离开距离            moveTailToHead();            mMoveLen = mMoveLen - MARGIN_ALPHA * mMinTextSize;        } else if (mMoveLen < -MARGIN_ALPHA * mMinTextSize / 2)        {            // 往上滑超过离开距离            moveHeadToTail();            mMoveLen = mMoveLen + MARGIN_ALPHA * mMinTextSize;        }        mLastDownY = event.getY();        invalidate();    }    private void doUp(MotionEvent event)    {        // 抬起手后mCurrentSelected的位置由当前位置move到中间选中位置        if (Math.abs(mMoveLen) < 0.0001)        {            mMoveLen = 0;            return;        }        if (mTask != null)        {            mTask.cancel();            mTask = null;        }        mTask = new MyTimerTask(updateHandler);        timer.schedule(mTask, 0, 10);    }    class MyTimerTask extends TimerTask    {        Handler handler;        public MyTimerTask(Handler handler)        {            this.handler = handler;        }        @Override        public void run()        {            handler.sendMessage(handler.obtainMessage());        }    }    public interface onSelectListener    {        void onSelect(String text);    }}

然后，dialog对话框的布局代码：

最后就是在activity中需要的地方，使用对话框弹出选择：

首先，声明当前性别

public class PickViewActivity extends Activity {    Button btnShow;    PickView pickView;    //声明当前性别    String currentSex;View view = View.inflate(this,R.layout.sexpick_layout,null);mDialog = new MyDialog(this,view);pickView = (PickView)view.findViewById(R.id.pvPickView);//定义滚动选择器的数据项ArrayList grade = new ArrayList<>();grade.add("女");grade.add("男");//为滚动选择器设置数据pickView.setData(grade);pickView.setOnSelectListener(new PickView.onSelectListener() {    @Override    public void onSelect(String text) {        Log.i("tag","选择了"+text);        currentSex= text;    }});mDialog.show();

其中的MyDialog是我自己写的dialog工具类，具体代码如下：

public class MyDialog extends Dialog {    Activity context;    View view;    public MyDialog(Activity context,View view) {        super(context);        this.context = context;        this.view = view;    }    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        requestWindowFeature(Window.FEATURE_NO_TITLE);        getWindow().setBackgroundDrawableResource(R.color.bantouming_color);        /*view = View.inflate(this.context, R.layout.dialog_user_headimg, null);*/        setContentView(view);        WindowManager m = context.getWindowManager();        Display d = m.getDefaultDisplay();        WindowManager.LayoutParams p = getWindow().getAttributes();  //获取对话框当前的参数值        p.height = (int) (d.getHeight() * 0.35);   //高度设置为屏幕的0.6        p.width = (int) (d.getWidth() * 0.7);    //宽度设置为屏幕的0.95        getWindow().setAttributes(p);     //设置生效    }}

原作者:Angel_jn

文章连接:https://blog.csdn.net/Angel_jn/article/details/54177160

更多相关文章

随机推荐