[Android实例] 侧边字母滑动检索控件

该篇文章从eoeAndroid搬迁过来的，原文地址：[Android实例] 侧边字母滑动检索控件

自定义侧边滑动检索控件，能根据A~Z字母进行检索，类似微信，通讯录右侧字母检索方式

主要代码：

@Override    protected void onDraw(Canvas canvas) {        // TODO Auto-generated method stub        super.onDraw(canvas);        // 获取焦点改变背景颜色        int height = getHeight();        int width = getWidth();        int sigleHeight = height / b.length;        for (int i = 0; i < b.length; i++) {            paint.setColor(Color.BLACK);            paint.setTypeface(Typeface.DEFAULT_BOLD);            paint.setAntiAlias(true);            paint.setTextSize(20);            // 选中状态            if (i == position) {                paint.setColor(Color.BLUE);                paint.setTextSize(30);                paint.setFakeBoldText(true);            }            // x坐标等于中间-字符串宽度的一半.            float xPos = width / 2 - paint.measureText(b[i]) / 2;            float yPos = sigleHeight * i + sigleHeight;            canvas.drawText(b[i], xPos, yPos, paint);            paint.reset();// 重置画笔        }    }    @SuppressWarnings("deprecation")    @Override    public boolean dispatchTouchEvent(MotionEvent event) {        // TODO Auto-generated method stub        int action = event.getAction();        float y = event.getY() - getY();        int oldPosition = position;        // 点击y坐标所占总高度的比例*b数组的长度就等于点击b中的个数.        int c = 0;        if (y >= 0 && y <= getHeight()) {            c = (int) (y / getHeight() * b.length);        } else if (y > getHeight()) {            c = b.length - 1;        }        if (action == MotionEvent.ACTION_UP) {            setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));            position = -1;            if (showChooseText != null) {                showChooseText.setVisibility(View.INVISIBLE);            }        } else {            setBackgroundDrawable(new ColorDrawable(Color.GRAY));            setBackgroundColor(Color.GRAY);            if (oldPosition != c) {                if (c >= 0 && c < b.length) {                    if (onTouchingChangedListener != null) {                        onTouchingChangedListener.onTouchingChanged(b[c]);                    }                }                if (showChooseText != null) {                    showChooseText.setText(b[c]);                    showChooseText.setVisibility(View.VISIBLE);                }                position = c;            }        }        invalidate();        return true;    }

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