In Android, the position of popupwindow is usually determined by the showasdropdown function. This function has two overload functions, which are defined as follows:
Public void showasdropdown (view anchor) {<br/> showasdropdown (anchor, 0, 0); <br/>}</P> <p> Public void showasdropdown (view anchor, int xoff, int yoff) {<br/> If (isshowing () | mcontentview = NULL) {<br/> return; <br/>}</P> <p> registerforscrollchanged (anchor, xoff, yoff); </P> <p> misshowing = true; <br/> misdropdown = true; </P> <p> windowmanager. layoutparams P = createpopuplayout (anchor. getwindowtoken (); <br/> preparepopup (p); </P> <p> updateaboveanchor (finddropdownposition (anchor, P, xoff, yoff )); </P> <p> If (mheightmode <0) p. height = mlastheight = mheightmode; <br/> If (mwidthmode <0) p. width = mlastwidth = mwidthmode; </P> <p> P. windowanimations = computeanimationresource (); </P> <p> invokepopup (p); <br/>}
That is to say, when the first function is called, the offset of the X and Y coordinates is 0 by default. In this case, the result of popupwindow is shown in the following figure. To implement popupwindow display at the bottom of Wenwen, the programmer needs to calculate the coordinate offset by himself. As shown in the lower right figure, When you click Wenwen, popupwindow is displayed at the bottom, this is exactly what we need. symmetry is a kind of beauty.
The key to code implementation is to click the response function after Wenwen. The code is directly used here:
Public void onclick (view v) {<br/> layoutinflater mlayoutinflater = (layoutinflater) getsystemservice (layout_inflater_service); <br/> viewgroup menuview = (viewgroup) mlayoutinflater. inflate (<br/> r. layout. tips, null, true); <br/> PW = new popupwindow (menuview, layoutparams. wrap_content, <br/> layoutparams. wrap_content, true); <br/> // click the return key to disappear without affecting the background. In this case, the setoutsidetouchable function is set to false even if it is set to <br/> // click popu. On the screen outside pwindow, popupwindow disappears. On the contrary, if backgrounddrawable is not set <br/> //, click the return key popupwindow, instant setoutsidetouchable is set to true <br/> // click the screen outside popupwindow, And the popupwindow will not disappear <br/> PW. setbackgrounddrawable (New colordrawable (color. transparent); <br/> PW. setoutsidetouchable (false); // you can specify whether to enable click to disappear. Is it useful? <Br/> PW. setanimationstyle (R. style. popupanimation); // set the animation </P> <p> // calculate the offset of the X axis to make the popupwindow appear at the bottom of the title, the unit here is pixels <br/> int xoffinpixels = screentools. getinstance (popdemoactivity. this ). getwidth ()/2-titlename. getwidth ()/2; <br/> // convert pixels to dip <br/> int xoffindip = screentools. getinstance (popdemoactivity. this ). px2dip (xoffinpixels); <br/> PW. showasdropdown (titlename,-xoffindip, 0); <br/> // PW. showasdropdown (titlename); <br/> PW. update (); </P> <p> textview TV = (textview) menuview. findviewbyid (R. id. tips_ OK); <br/> TV. setonclicklistener (new view. onclicklistener () {</P> <p> Public void onclick (view v) {<br/> PW. dismiss (); <br/>}</P> <p >}); </P> <p>}