Android类似ios的SideBar字母在屏幕中间，动态设置之母数量

按照项目要求我们做的类似通讯录效果是这样的：

然后根据这样来开发，当时找了好多代码，看到的只是一个版本的代码。自己就在其基础上修改了代码。正好这边记录一下。直接贴代码

public class SideBar extends View {private OnTouchingLetterChangedListener onTouchingLetterChangedListener;public static String[] b ;private int choose = -1;private Paint paint = new Paint();private TextView mTextDialog;    private Context context;public void setTextView(TextView mTextDialog) {this.mTextDialog = mTextDialog;}public SideBar(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);public SideBar(Context context, AttributeSet attrs) {super(context, attrs);}public SideBar(Context context,String[] b) {super(context);this.b= b;//传过来的数组this.context = context;}protected void onDraw(Canvas canvas) {super.onDraw(canvas);int height = b.length*40;//获取总长度，设定每个字母高度为40pxint topOffset = (getHeight()-(b.length*40))/2;//获取父控件的高度减去字母总长度/2；目的是让字母在屏幕中间int width = getWidth(); for (int i = 0; i < b.length; i++) {paint.setColor(Color.parseColor("#007aff"));// paint.setColor(Color.WHITE);paint.setTypeface(Typeface.DEFAULT_BOLD);paint.setAntiAlias(true);paint.setTextSize(24);//设置文字大小if (i == choose) {paint.setColor(Color.parseColor("#3399ff"));paint.setFakeBoldText(true);}float xPos = width / 2 - paint.measureText(b[i]) / 2;float yPos = i *40+ topOffset;//画每一个字符canvas.drawText(b[i], xPos, yPos, paint);paint.reset();}}@Overridepublic boolean dispatchTouchEvent(MotionEvent event) {String Tag = "Hight";final int action = event.getAction();int topOffset = (getHeight()-(b.length*40))/2;final float y = event.getY();final int oldChoose = choose;final OnTouchingLetterChangedListener listener = onTouchingLetterChangedListener;final int c = (int) ((y - topOffset) /40); //点击的时候获取点击时 //画每个字符的y坐标是 字母的位置i * 40+topOffset，现在要根据y来得到i,逆运算即可Log.e(Tag, c+"=getHeight()="+getHeight()+"=y="+y);switch (action) {case MotionEvent.ACTION_UP:setBackgroundDrawable(new ColorDrawable(0x00000000));choose = -1;//invalidate();if (mTextDialog != null) {mTextDialog.setVisibility(View.INVISIBLE);}break;default:setBackgroundResource(R.drawable.sidebar_background);if (oldChoose != c) {if (c >= 0 && c < b.length) {if (listener != null) {listener.onTouchingLetterChanged(b[c]);}if (mTextDialog != null) {mTextDialog.setText(b[c]);mTextDialog.setVisibility(View.VISIBLE);}choose = c;invalidate();}}break;}return true;}public void setOnTouchingLetterChangedListener(OnTouchingLetterChangedListener onTouchingLetterChangedListener) {this.onTouchingLetterChangedListener = onTouchingLetterChangedListener;}public interface OnTouchingLetterChangedListener {public void onTouchingLetterChanged(String s);}

在activity中，在拼音排完序之后，根据获取的list的长度来定义一个数组（长度一致）。在对拼音排序时，数组不断添加元素。对数组去重，然后排序就可以使用了。

下边是去重：

public void quchong(String[] array) {List<String> list = new ArrayList<String>();for (int i = 0; i < array.length; i++) {list.add(array[i]);}Set<String> numSet = new HashSet<String>();numSet.addAll(list);Log.e("==00==", numSet + "");bb = new String[numSet.size()];Iterator<String> iterator = numSet.iterator();for (int i = 0; i < numSet.size(); i++) {bb[i] = iterator.next();}Arrays.sort(bb);}

注意：要在获取完数据之后通过handler来动态添加SideBar

Handler handler = new Handler() {public void handleMessage(Message msg) {setSidBar();}};

setSidBar();方法如下：

private void setSidBar() {quchong(b);// 获取的数组需要去重，排列// 添加sideBarsidebar = new SideBar(this, bb);LayoutParams  lypParams = new LayoutParams(50, LayoutParams.WRAP_CONTENT,5);//三个参数的最后一个是 gravity(5表示右边)frameLayout.addView(sidebar, lypParams);// SideBar.b = listuse.get(location)// 设置右侧触摸监听sidebar.setOnTouchingLetterChangedListener(new OnTouchingLetterChangedListener() {@Overridepublic void onTouchingLetterChanged(String s) {// 该字母首次出现的位置int position = adapter.getPositionForSection(s.charAt(0));if (position != -1) {lv_contactsa.setSelection(position);}}});sidebar.setTextView(tv_contactsac_center_dialog);}

核心的都在这里，其他的相信大家都能找到木有经过改造的代码。