Android仿微信通讯录滑动快速定位功能

先给大家展示下效果图：

实现代码如下：

下面简单说下实现原理。

public class indexbar extends linearlayout implements view.ontouchlistener {
  private static final string[] indexes = new string[]{"#", "a", "b", "c", "d", "e", "f", "g", "h",
      "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"};
  private static final int touched_background_color = 0x40000000;
  private onindexchangedlistener mlistener;
  public void setonindexchangedlistener(onindexchangedlistener listener) {
    mlistener = listener;
  }
  public indexbar(context context) {
    this(context, null);
  }
  public indexbar(context context, attributeset attrs) {
    this(context, attrs, 0);
  }
  public indexbar(context context, attributeset attrs, int defstyleattr) {
    super(context, attrs, defstyleattr);
    init(attrs);
  }
  private void init(attributeset attrs) {
    typedarray ta = getcontext().obtainstyledattributes(attrs, r.styleable.indexbar);
    float indextextsize = ta.getdimension(r.styleable.indexbar_indextextsize, utils.sp2px(getcontext(), 12));
    int indextextcolor = ta.getcolor(r.styleable.indexbar_indextextcolor, 0xff616161);
    ta.recycle();
    setorientation(vertical);
    setontouchlistener(this);
    for (string index : indexes) {
      textview text = new textview(getcontext());
      text.settext(index);
      text.settextsize(typedvalue.complex_unit_px, indextextsize);
      text.settextcolor(indextextcolor);
      text.setgravity(gravity.center);
      linearlayout.layoutparams params = new linearlayout.layoutparams(viewgroup.layoutparams.match_parent, 0, 1);
      text.setlayoutparams(params);
      addview(text);
    }
  }
  @override
  public boolean ontouch(view v, motionevent event) {
    switch (event.getaction()) {
      case motionevent.action_down:
        setbackgroundcolor(touched_background_color);
        handle(v, event);
        return true;
      case motionevent.action_move:
        handle(v, event);
        return true;
      case motionevent.action_up:
        setbackgroundcolor(color.transparent);
        handle(v, event);
        return true;
    }
    return super.ontouchevent(event);
  }
  private void handle(view v, motionevent event) {
    int y = (int) event.gety();
    int height = v.getheight();
    int position = indexes.length * y / height;
    if (position < 0) {
      position = 0;
    } else if (position >= indexes.length) {
      position = indexes.length - 1;
    }
    string index = indexes[position];
    boolean showindicator = event.getaction() != motionevent.action_up;
    if (mlistener != null) {
      mlistener.onindexchanged(index, showindicator);
    }
  }
  public interface onindexchangedlistener {
    void onindexchanged(string index, boolean showindicator);
  }
}

使用

public class companyactivity extends baseactivity implements indexbar.onindexchangedlistener {
  @bind(r.id.lv_company)
  listview lvcompany;
  @bind(r.id.ib_indicator)
  indexbar ibindicator;
  @bind(r.id.tv_indicator)
  textview tvindicator;
  private list<companyentity> mcompanylist = new arraylist<>();
  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_company);
    // ...
  }
  @override
  public void onindexchanged(string index, boolean showindicator) {
    int position = -1;
    for (companyentity company : mcompanylist) {
      if (textutils.equals(company.getname(), index)) {
        position = mcompanylist.indexof(company);
        break;
      }
    }
    if (position != -1) {
      lvcompany.setselection(position);
    }
    tvindicator.settext(index);
    tvindicator.setvisibility(showindicator ? view.visible : view.gone);
  }
}

继承自linearlayout，添加了26个字母索引textview，当手指滑动时通知activity更新界面。

核心是ontouchlistener，手指滑动的时候根据当前y坐标计算出手指所在的索引位置，要注意临界值。

以上所述是小编给大家介绍的android仿微信通讯录滑动快速定位功能，希望对大家有所帮助