类似于抽奖活动的小程序

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Random;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationSet;
import android.view.animation.ScaleAnimation;
import android.widget.TextView;
public class MainActivity extends Activity {
	private TextView mTv;
	private ArrayList<String> nameList;
	private Random r;
	private String rname = null;
	int i = 0;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		mTv = (TextView) this.findViewById(R.id.tv_showname);
		nameList = new ArrayList<String>();

		readData();
	}
	private void readData() {
		// 直接从文件里拿到全部人名字，放到集合里
		// 随机为集合长度，那个随机所以人名字显示到mTv
		try {
			InputStream is = this.getAssets().open("name.txt");
			BufferedReader br = new BufferedReader(new InputStreamReader(is,
					"utf-8"));
			String line = null;
			while ((line = br.readLine()) != null) {
				nameList.add(line);// 遍历每一行的名字放入List集合
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	public void rName(View view) {
		final int size = nameList.size();
		r = new Random();
		new Thread() {
			public void run() {
				// 得到一个随机索引
				for (i =0; i < 4; i++) {
					try {
						Thread.sleep(300);
						int index = r.nextInt(size);
						rname = nameList.get(index);

						runOnUiThread(new Runnable() {
							@Override
							public void run() {
								// 显示
								mTv.setText(rname);
								if (i == 4) {
									showAnim();
								}
							}
						});
					
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
				}
			};
		}.start();
	}
	
	/**
	 * 显示缩放动画
	 */
	private void showAnim(){
		AnimationSet set = new AnimationSet(false);
		
		ScaleAnimation anim = new ScaleAnimation(0, 4, 0,4,
				Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
		anim.setDuration(1000);
		
		ScaleAnimation anim1 = new ScaleAnimation(4, 0, 4, 0,
				Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
		anim1.setDuration(1000);
		set.addAnimation(anim);
		set.addAnimation(anim1);
		mTv.startAnimation(set);
	}
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="rName"
        android:text="抽奖活动" />

    <TextView
        android:id="@+id/tv_showname"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:gravity="center"
        android:text="恭喜你！"
        android:textColor="#FF0000"
        android:textSize="33dp" />

</RelativeLayout>

 

 

在assets文件下创建name.text

效果: