項(xiàng)目目標(biāo):明白面向?qū)ο蠛兔嫦蜻^(guò)程的區(qū)別,初步了解android studio開(kāi)發(fā)流程,并寫(xiě)一個(gè)抽獎(jiǎng)機(jī)Demo
1、面向?qū)ο蠛兔嫦蜻^(guò)程的區(qū)別:
面向過(guò)程的編程是步驟化的,流程化的,復(fù)用性低;
面向?qū)ο蟮木幊淌前鍓K功能化的,封裝保密性高,一個(gè)類能反復(fù)使用。
2、抽獎(jiǎng)機(jī)Demo
package luckdog.luckydog;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import java.util.Random;
import java.util.Timer;
import java.util.TimerTask;
public class Luckydog extends ActionBarActivity {
String[] names =new String[]{"炫灬月影蕭夢(mèng)","絕情人","靈韻飛舞","淺夏詩(shī)韻","嗜血的靈魂","北沐城歌","鯰汐如妳","逆轉(zhuǎn)的時(shí)光","水墨"};
Timer timer;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_luckydog);
}
//按鈕點(diǎn)擊事件
public void start(View view){
//將View轉(zhuǎn)化為Button
Button btn =(Button)view;
//獲取當(dāng)前的標(biāo)題
String title = btn.getText().toString();
//判斷按鈕的標(biāo)題
if (title.equals("開(kāi)始抽獎(jiǎng)")) {
//設(shè)置為暫停
btn.setText("暫停");
//創(chuàng)建定時(shí)器
timer =new Timer();
//每隔一段時(shí)間執(zhí)行一個(gè)任務(wù)
timer.schedule(new TimerTask() {
@Override
public void run() {
produceluckydog();
}
},0,200);
}else {
//設(shè)置為開(kāi)始抽獎(jiǎng)
btn.setText("開(kāi)始抽獎(jiǎng)");
//關(guān)閉定時(shí)器
timer.cancel();
}
}
//產(chǎn)生幸運(yùn)者顯示到文本上
public void produceluckydog(){
//產(chǎn)生一個(gè)隨機(jī)數(shù)
Random random = new Random();
int index = Math.abs(random.nextInt())%names.length;
//從數(shù)組里面取出這個(gè)名字
String name =names[index];
//將名字顯示到文本框上
TextView tv =(TextView)findViewById(R.id.tv_name);
tv.setText(name);
}
}
成果展示:

QQ圖片20200316182019.gif
存在問(wèn)題:
1、隨機(jī)產(chǎn)生的數(shù)可能為負(fù)導(dǎo)致應(yīng)用崩潰.
解決辦法:用Math.abs()取絕對(duì)值。
2、將名字顯示到文本框上時(shí)提示View無(wú)法轉(zhuǎn)化為T(mén)extView.
解決辦法在findViewById()前加(TextView)強(qiáng)制轉(zhuǎn)換。