Android列表實現(3)_自定義列表適配器思路及實現代碼

下面的例子為使用自定義的列表適配器來顯示列表。
代碼如下：

View Code
import android.os.Bundle;
import android.app.ListActivity;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.TextView;
public class MainActivity extends ListActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setListAdapter(new SpeechListAdapter(this));
}
/**
* A sample ListAdapter that presents content from arrays of speeches and
* text.
*
*/
private class SpeechListAdapter extends BaseAdapter {
public SpeechListAdapter(Context context) {
mContext = context;
}
/**
* The number of items in the list is determined by the number of speeches
* in our array.
*
* @see android.widget.ListAdapter#getCount()
*/
public int getCount() {
return mTitles.length;
}
/**
* Since the data comes from an array, just returning the index is
* sufficent to get at the data. If we were using a more complex data
* structure, we would return whatever object represents one row in the
* list.
*
* @see android.widget.ListAdapter#getItem(int)
*/
public Object getItem(int position) {
return position;
}
/**
* Use the array index as a unique id.
*
* @see android.widget.ListAdapter#getItemId(int)
*/
public long getItemId(int position) {
return position;
}
/**
* Make a SpeechView to hold each row.
*
* @see android.widget.ListAdapter#getView(int, android.view.View,
* android.view.ViewGroup)
*/
public View getView(int position, View convertView, ViewGroup parent) {
SpeechView sv;
if (convertView == null) {
sv = new SpeechView(mContext, mTitles[position],
mDialogue[position]);
} else {
sv = (SpeechView) convertView;
sv.setTitle(mTitles[position]);
sv.setDialogue(mDialogue[position]);
}
return sv;
}
/**
* Remember our context so we can use it when constructing views.
*/
private Context mContext;
/**
* Our data, part 1.
*/
private String[] mTitles =
{
"Henry IV (1)",
"Henry V",
"Henry VIII",
"Richard II",
"Richard III",
"Merchant of Venice",
"Othello",
"King Lear"
};
/**
* Our data, part 2.
*/
private String[] mDialogue =
{
"So shaken as we are, so wan with care," +
"Find we a time for frighted peace to pant," +
"And breathe short-winded accents of new broils" +
"To be commenced in strands afar remote." +
"No more the thirsty entrance of this soil" +
"Shall daub her lips with her own children's blood;" +
"Nor more shall trenching war channel her fields," +
"Nor bruise her flowerets with the armed hoofs" +
"Of hostile paces: those opposed eyes," +
"Which, like the meteors of a troubled heaven," +
"All of one nature, of one substance bred," +
"Did lately meet in the intestine shock" +
"And furious close of civil butchery" +
"Shall now, in mutual well-beseeming ranks," +
"March all one way and be no more opposed" +
"Against acquaintance, kindred and allies:" +
"The edge of war, like an ill-sheathed knife," +
"No more shall cut his master. Therefore, friends," +
"As far as to the sepulchre of Christ," +
"Whose soldier now, under whose blessed cross" +
"We are impressed and engaged to fight," +
"Forthwith a power of English shall we levy;" +
"Whose arms were moulded in their mothers' womb" +
"To chase these pagans in those holy fields" +
"Over whose acres walk'd those blessed feet" +
"Which fourteen hundred years ago were nail'd" +
"For our advantage on the bitter cross." +
"But this our purpose now is twelve month old," +
"And bootless 'tis to tell you we will go:" +
"Therefore we meet not now. Then let me hear" +
"Of you, my gentle cousin Westmoreland," +
"What yesternight our council did decree" +
"In forwarding this dear expedience.",
"Hear him but reason in divinity," +
"And all-admiring with an inward wish" +
"You would desire the king were made a prelate:" +
"Hear him debate of commonwealth affairs," +
"You would say it hath been all in all his study:" +
"List his discourse of war, and you shall hear" +
"A fearful battle render'd you in music:" +
"Turn him to any cause of policy," +
"The Gordian knot of it he will unloose," +
"Familiar as his garter: that, when he speaks," +
"The air, a charter'd libertine, is still," +
"And the mute wonder lurketh in men's ears," +
"To steal his sweet and honey'd sentences;" +
"So that the art and practic part of life" +
"Must be the mistress to this theoric:" +
"Which is a wonder how his grace should glean it," +
"Since his addiction was to courses vain," +
"His companies unletter'd, rude and shallow," +
"His hours fill'd up with riots, banquets, sports," +
"And never noted in him any study," +
"Any retirement, any sequestration" +
"From open haunts and popularity.",
"I come no more to make you laugh: things now," +
"That bear a weighty and a serious brow," +
"Sad, high, and working, full of state and woe," +
"Such noble scenes as draw the eye to flow," +
"We now present. Those that can pity, here" +
"May, if they think it well, let fall a tear;" +
"The subject will deserve it. Such as give" +
"Their money out of hope they may believe," +
"May here find truth too. Those that come to see" +
"Only a show or two, and so agree" +
"The play may pass, if they be still and willing," +
"I'll undertake may see away their shilling" +
"Richly in two short hours. Only they" +
"That come to hear a merry bawdy play," +
"A noise of targets, or to see a fellow" +
"In a long motley coat guarded with yellow," +
"Will be deceived; for, gentle hearers, know," +
"To rank our chosen truth with such a show" +
"As fool and fight is, beside forfeiting" +
"Our own brains, and the opinion that we bring," +
"To make that only true we now intend," +
"Will leave us never an understanding friend." +
"Therefore, for goodness' sake, and as you are known" +
"The first and happiest hearers of the town," +
"Be sad, as we would make ye: think ye see" +
"The very persons of our noble story" +
"As they were living; think you see them great," +
"And follow'd with the general throng and sweat" +
"Of thousand friends; then in a moment, see" +
"How soon this mightiness meets misery:" +
"And, if you can be merry then, I'll say" +
"A man may weep upon his wedding-day.",
"First, heaven be the record to my speech!" +
"In the devotion of a subject's love," +
"Tendering the precious safety of my prince," +
"And free from other misbegotten hate," +
"Come I appellant to this princely presence." +
"Now, Thomas Mowbray, do I turn to thee," +
"And mark my greeting well; for what I speak" +
"My body shall make good upon this earth," +
"Or my divine soul answer it in heaven." +
"Thou art a traitor and a miscreant," +
"Too good to be so and too bad to live," +
"Since the more fair and crystal is the sky," +
"The uglier seem the clouds that in it fly." +
"Once more, the more to aggravate the note," +
"With a foul traitor's name stuff I thy throat;" +
"And wish, so please my sovereign, ere I move," +
"What my tongue speaks my right drawn sword may prove.",
"Now is the winter of our discontent" +
"Made glorious summer by this sun of York;" +
"And all the clouds that lour'd upon our house" +
"In the deep bosom of the ocean buried." +
"Now are our brows bound with victorious wreaths;" +
"Our bruised arms hung up for monuments;" +
"Our stern alarums changed to merry meetings," +
"Our dreadful marches to delightful measures." +
"Grim-visaged war hath smooth'd his wrinkled front;" +
"And now, instead of mounting barded steeds" +
"To fright the souls of fearful adversaries," +
"He capers nimbly in a lady's chamber" +
"To the lascivious pleasing of a lute." +
"But I, that am not shaped for sportive tricks," +
"Nor made to court an amorous looking-glass;" +
"I, that am rudely stamp'd, and want love's majesty" +
"To strut before a wanton ambling nymph;" +
"I, that am curtail'd of this fair proportion," +
"Cheated of feature by dissembling nature," +
"Deformed, unfinish'd, sent before my time" +
"Into this breathing world, scarce half made up," +
"And that so lamely and unfashionable" +
"That dogs bark at me as I halt by them;" +
"Why, I, in this weak piping time of peace," +
"Have no delight to pass away the time," +
"Unless to spy my shadow in the sun" +
"And descant on mine own deformity:" +
"And therefore, since I cannot prove a lover," +
"To entertain these fair well-spoken days," +
"I am determined to prove a villain" +
"And hate the idle pleasures of these days." +
"Plots have I laid, inductions dangerous," +
"By drunken prophecies, libels and dreams," +
"To set my brother Clarence and the king" +
"In deadly hate the one against the other:" +
"And if King Edward be as true and just" +
"As I am subtle, false and treacherous," +
"This day should Clarence closely be mew'd up," +
"About a prophecy, which says that 'G'" +
"Of Edward's heirs the murderer shall be." +
"Dive, thoughts, down to my soul: here" +
"Clarence comes.",
"To bait fish withal: if it will feed nothing else," +
"it will feed my revenge. He hath disgraced me, and" +
"hindered me half a million; laughed at my losses," +
"mocked at my gains, scorned my nation, thwarted my" +
"bargains, cooled my friends, heated mine" +
"enemies; and what's his reason? I am a Jew. Hath" +
"not a Jew eyes? hath not a Jew hands, organs," +
"dimensions, senses, affections, passions? fed with" +
"the same food, hurt with the same weapons, subject" +
"to the same diseases, healed by the same means," +
"warmed and cooled by the same winter and summer, as" +
"a Christian is? If you prick us, do we not bleed?" +
"if you tickle us, do we not laugh? if you poison" +
"us, do we not die? and if you wrong us, shall we not" +
"revenge? If we are like you in the rest, we will" +
"resemble you in that. If a Jew wrong a Christian," +
"what is his humility? Revenge. If a Christian" +
"wrong a Jew, what should his sufferance be by" +
"Christian example? Why, revenge. The villany you" +
"teach me, I will execute, and it shall go hard but I" +
"will better the instruction.",
"Virtue! a fig! 'tis in ourselves that we are thus" +
"or thus. Our bodies are our gardens, to the which" +
"our wills are gardeners: so that if we will plant" +
"nettles, or sow lettuce, set hyssop and weed up" +
"thyme, supply it with one gender of herbs, or" +
"distract it with many, either to have it sterile" +
"with idleness, or manured with industry, why, the" +
"power and corrigible authority of this lies in our" +
"wills. If the balance of our lives had not one" +
"scale of reason to poise another of sensuality, the" +
"blood and baseness of our natures would conduct us" +
"to most preposterous conclusions: but we have" +
"reason to cool our raging motions, our carnal" +
"stings, our unbitted lusts, whereof I take this that" +
"you call love to be a sect or scion.",
"Blow, winds, and crack your cheeks! rage! blow!" +
"You cataracts and hurricanoes, spout" +
"Till you have drench'd our steeples, drown'd the cocks!" +
"You sulphurous and thought-executing fires," +
"Vaunt-couriers to oak-cleaving thunderbolts," +
"Singe my white head! And thou, all-shaking thunder," +
"Smite flat the thick rotundity o' the world!" +
"Crack nature's moulds, an germens spill at once," +
"That make ingrateful man!"
};
}
/**
* We will use a SpeechView to display each speech. It's just a LinearLayout
* with two text fields.
*
*/
private class SpeechView extends LinearLayout {
public SpeechView(Context context, String title, String words) {
super(context);
this.setOrientation(VERTICAL);
// Here we build the child views in code. They could also have
// been specified in an XML file.
mTitle = new TextView(context);
mTitle.setText(title);
addView(mTitle, new LinearLayout.LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
mDialogue = new TextView(context);
mDialogue.setText(words);
addView(mDialogue, new LinearLayout.LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
}
/**
* Convenience method to set the title of a SpeechView
*/
public void setTitle(String title) {
mTitle.setText(title);
}
/**
* Convenience method to set the dialogue of a SpeechView
*/
public void setDialogue(String words) {
mDialogue.setText(words);
}
private TextView mTitle;
private TextView mDialogue;
}
}

該例子中自定義了適配器 SpeechListAdapter (其繼承父類BaseAdapter)以及作為記錄模板的 SpeechView（其父類為LinearLayout）。
SpeechListAdapter中的方法getView實現了返回指定位置的記錄顯示對象的邏輯。