Android Studio编程第二篇：电机筛查任务（MOT）

目标

彩色的十字架出现在屏幕上的不同位置，一次一个。参与者必须尽可能快速和准确地选择屏幕上的十字架。

代码

MainActivity

package com.example.mot;

import androidx.appcompat.app.AppCompatActivity;

import android.content.res.Resources;
import android.os.Bundle;
import android.os.Handler;
import android.util.DisplayMetrics;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import org.w3c.dom.Text;

import java.util.Random;
import java.util.concurrent.TimeUnit;

public class MainActivity extends AppCompatActivity {
    Integer randomX = 0;
    Integer randomY = 0;
    Integer screenWidth = 0;
    Integer screenHeight = 0;
    Integer round = 0;
    long startTime = 0;
    long endTime = 0;
    long allTime = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        getScreen();

        genRandomButton();

        Button button = findViewById(R.id.button);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                button.setVisibility(View.INVISIBLE);
                endTime = System.currentTimeMillis();
                long elapseTime = endTime - startTime;
                allTime = allTime + elapseTime;
                round++;
                TextView textView = findViewById(R.id.textView);
                textView.setText("第" + round + "轮用时：" + elapseTime + "毫秒\n" + "总共用时：" + allTime + "毫秒");
                try {
                    TimeUnit.MILLISECONDS.sleep(genRandomTime());
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                genRandomButton();
            }
        });

    }

    public  void getScreen() {
        Resources resources = this.getResources();
        DisplayMetrics dm = resources.getDisplayMetrics();
        screenWidth = dm.widthPixels;
        screenHeight = dm.heightPixels;
    }

    public void genRandomButton(){
        Random rand = new Random();
        randomX = rand.nextInt(screenWidth - 120) + 60;
        randomY = rand.nextInt(screenWidth - 120) + 60;
        Button button = findViewById(R.id.button);
        button.setX(randomX);
        button.setY(randomY);
        button.setVisibility(View.VISIBLE);
        startTime = System.currentTimeMillis();
    }

    public Integer genRandomTime(){
        Random rand = new Random();
        Integer randomTime = rand.nextInt(3000) + 200;
        return randomTime;
    }
}

xml布局

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_height="match_parent"
    android:layout_width="match_parent"
    tools:context=".MainActivity" >


    <Button
        android:id="@+id/button"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:background="@drawable/ring"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.335"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:visibility="visible"
        app:layout_constraintVertical_bias="0.62" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="200dp"
        android:layout_height="50dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.022" />
</androidx.constraintlayout.widget.ConstraintLayout>

效果

原文地址：http://www.cnblogs.com/z5onk0/p/16852612.html