android popupwindow用法详解

本文实例为大家分享了android popupwindow的用法，供大家参考，具体内容如下

一、基本用法

一般做法，新建类继承popupwindow。例

/**
 * popupwindow基本用法
 * created by administrator on 2015/11/25.
 */
public class demobasepop extends popupwindow {
  private linearlayout linear_layout;
  private textview dbp_text;
  private context context;
  public demobasepop(final activity context) {
    super(context);
    this.context = context;
    view view = layoutinflater.from(context).inflate(r.layout.demo_base_pop,null);
 
    setcontentview(view);
    setwidth(viewgroup.layoutparams.match_parent);
    setheight(200);
//    setheight(viewgroup.layoutparams.match_parent);
 
    setfocusable(true);
    setbackgrounddrawable(new bitmapdrawable());
    settouchable(true);
    setoutsidetouchable(true);
    setanimationstyle(r.style.popwin_anim_style);
//    setanimationstyle(0);   0是没有animation
 
    initview(view);
 
  }
 
  private void initview(view view) {
    dbp_text = (textview) view.findviewbyid(r.id.dbp_text);
  }
 
}

研究下popupwindow源码，以showasdropdown来讲

public void showasdropdown(view anchor, int xoff, int yoff) {
    if (isshowing() || mcontentview == null) {
      return;
    }
 
    registerforscrollchanged(anchor, xoff, yoff);
 
    misshowing = true;
    misdropdown = true;
 
    windowmanager.layoutparams p = createpopuplayout(anchor.getwindowtoken());
    preparepopup(p);
 
    updateaboveanchor(finddropdownposition(anchor, p, xoff, yoff));
 
    if (mheightmode < 0) p.height = mlastheight = mheightmode;
    if (mwidthmode < 0) p.width = mlastwidth = mwidthmode;
 
    p.windowanimations = computeanimationresource();
 
    invokepopup(p);
  }

第11行创建windowmanager.layoutparams。第12行preparepopup（）中：

if (mbackground != null) {
      final viewgroup.layoutparams layoutparams = mcontentview.getlayoutparams();
      int height = viewgroup.layoutparams.match_parent;
      if (layoutparams != null &&
          layoutparams.height == viewgroup.layoutparams.wrap_content) {
        height = viewgroup.layoutparams.wrap_content;
      }
 
      // when a background is available, we embed the content view
      // within another view that owns the background drawable
      popupviewcontainer popupviewcontainer = new popupviewcontainer(mcontext);
      popupviewcontainer.layoutparams listparams = new popupviewcontainer.layoutparams(
          viewgroup.layoutparams.match_parent, height
      );
      popupviewcontainer.setbackgrounddrawable(mbackground);
      popupviewcontainer.addview(mcontentview, listparams);
 
      mpopupview = popupviewcontainer;
    } else {
      mpopupview = mcontentview;
    }

如果做了setbackgrounddrawable(new bitmapdrawable());那么mbackground则不为空，则会用popupviewcontainer作为mpopupview（即内容view）。而popupviewcontainer的dispatchkeyevent对返回键做了处理，按返回键后其中调用dismiss（）方法。其ontouchevent对触摸事件做了处理，其源码：

public boolean ontouchevent(motionevent event) {
      final int x = (int) event.getx();
      final int y = (int) event.gety();
      <span style="font-family: 宋体; font-size: 9pt;">//点击外部隐藏</span>
      if ((event.getaction() == motionevent.action_down)
          && ((x < 0) || (x >= getwidth()) || (y < 0) || (y >= getheight()))) {
        dismiss();
        return true;
      } else if (event.getaction() == motionevent.action_outside) {
        dismiss();
        return true;
      } else {
        return super.ontouchevent(event);
      }
    }

系统做了这些处理，随之而来一个问题，如果我们要监听物理返回键该怎么办。看了上面的过程，我们可以想到将

setbackgrounddrawable(null);然后通过设置view的key监听，监听到后做相应的处理。
view.setonkeylistener(new view.onkeylistener() {
      @override
      public boolean onkey(view v, int keycode, keyevent event) {
        if (event.getkeycode() == keyevent.keycode_back) {
          if (event.getaction() == keyevent.action_down
              && event.getrepeatcount() == 0) {
            outanimator.start();
            return true;
          }
        }
        return false;
      }
    });

效果图：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。