Step 7: listview (2)

This article from http://blog.csdn.net/hellogv/

 

In the sixth article of getting started with Android, listview (1) describes how to create a custom control with two lines of text and use it as an item of listview. Next, we will introduce the usage of listview and item in a more in-depth manner.

First, let's take a look at the code running result of this article. The item in this article is more left-side icon than the item in the previous article:

 

The source code of Main. XML is the same as that in the previous article. I will not explain it here. The code for item. XML is directly pasted, that is, it implements the imageitem UI:

<? XML version = "1.0" encoding = "UTF-8"?> <Br/> <relativelayout <br/> Android: layout_width = "fill_parent" <br/> xmns: Android = "http://schemas.android.com/apk/res/android" <br/> Android: layout_height = "wrap_content" <br/> Android: paddingbottom = "4dip" <br/> Android: paddingleft = "12dip"> <br/> <imageview <br/> Android: layout_width = "wrap_content" <br/> Android: Id = "@ + ID/itemimage" Android: layout_height = "fill_parent"> <br/> </imageview> <br/> <textview <br/> Android: text = "textview01" <br/> Android: layout_height = "wrap_content" <br/> Android: layout_width = "fill_parent" <br/> Android: Id = "@ + ID/itemtitle" Android: layout_torightof = "@ + ID/itemimage" Android: textsize = "20dip"> <br/> </textview> <br/> <textview <br/> Android: TEXT = "textview02" <br/> Android: layout_height = "wrap_content" <br/> Android: layout_width = "fill_parent" <br/> Android: id = "@ + ID/itemtext" Android: layout_torightof = "@ + ID/itemimage" Android: layout_below = "@ + ID/itemtitle"> <br/> </textview> <br/> </relativelayout>

Explain the code of item. xml: The relativelayout layout is used here. The key attributes of the control are:

Itemtitle attribute Android: layout_torightof = "@ + ID/itemimage", where itemtitle is on the right of itemimage;

Itemtext attributes: Android: layout_torightof = "@ + ID/itemimage", itemtext on the Right of itemimage, Android: layout_below = "@ + ID/itemtitle", and itemtext under itemtitle.

Finally, paste the source code of Java, with the focus on layoutinflate usage. Layoutinflate is used as follows:

• Layoutinflater is used to associate and instantiate a view object with an XML layout file.
• After the view object is instantiated, you can use findviewbyid () to find the component with the specified ID in the layout file.

 Package COM. testlistview; </P> <p> Import android. app. activity; <br/> Import android. content. context; <br/> Import android. OS. bundle; <br/> Import android. view. layoutinflater; <br/> Import android. view. view; <br/> Import android. view. viewgroup; <br/> Import android. widget. baseadapter; <br/> Import android. widget. imageview; <br/> Import android. widget. listview; <br/> Import android. widget. textview; </P> <p> public class testlistview extends activity {<br/> listview; <br/> string [] titles = {"Title 1 ", "title 2", "Title 3", "Title 4" };< br/> string [] texts = {"text content a", "text content B ", "text content C", "text content D" };< br/> int [] resids = {R. drawable. icon, R. drawable. icon, R. drawable. icon, R. drawable. icon}; </P> <p> @ override <br/> Public void oncreate (bundle savedinstancestate) {<br/> super. oncreate (savedinstancestate); <br/> setcontentview (R. layout. main); <br/> This. settitle ("baseadapter for listview"); <br/> listview = (listview) This. findviewbyid (R. id. listview1); <br/> listview. setadapter (New listviewadapter (titles, texts, resids); <br/>}</P> <p> public class listviewadapter extends baseadapter {<br/> View [] itemviews; </P> <p> Public listviewadapter (string [] itemtitles, string [] itemtexts, <br/> int [] itemimageres) {<br/> itemviews = new view [itemtitles. length]; </P> <p> for (INT I = 0; I <itemviews. length; I ++) {<br/> itemviews [I] = makeitemview (itemtitles [I], itemtexts [I], <br/> itemimageres [I]); <br/>}</P> <p> Public int getcount () {<br/> return itemviews. length; <br/>}</P> <p> Public View getitem (INT position) {<br/> return itemviews [position]; <br/>}</P> <p> Public long getitemid (INT position) {<br/> return position; <br/>}</P> <p> private view makeitemview (string strtitle, string strtext, int resid) {<br/> layoutinflater Inflater = (layoutinflater) testlistview. this <br/>. getsystemservice (context. layout_inflater_service); </P> <p> // use the itemview and R. layout. item Association <br/> View itemview = Inflater. inflate (R. layout. item, null); </P> <p> // instance R through the findviewbyid () method. layout. <br/> textview Title = (textview) itemview. findviewbyid (R. id. itemtitle); <br/> title. settext (strtitle); <br/> textview text = (textview) itemview. findviewbyid (R. id. itemtext); <br/> text. settext (strtext); <br/> imageview image = (imageview) itemview. findviewbyid (R. id. itemimage); <br/> image. setimageresource (resid); </P> <p> return itemview; <br/>}</P> <p> Public View getview (INT position, view convertview, viewgroup parent) {<br/> If (convertview = NULL) <br/> return itemviews [position]; <br/> return convertview; <br/>}</P> <p>}