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【安卓开发】【Android】做一个简单的钢琴模拟器

news 2025/10/18 23:44:44

说明

仅作为学习用途。

一、效果展示

从豪华别墅进入钢琴房，点击钢琴，呼出键盘（约1个八度），点击相应的键位，即可弹奏。效果如下：

piano

图片效果：

在这里插入图片描述

二、活动代码

// 颐居·沙发房
package com.lycbuaacs.my_hg;import static android.view.View.INVISIBLE;
import static android.view.View.VISIBLE;import android.annotation.SuppressLint;
import android.content.Intent;
import android.graphics.Typeface;
import android.media.AudioAttributes;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioTrack;
import android.os.Bundle;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;public class MainActivity23 extends AppCompatActivity {public static class ToneGenerator {private static final int SAMPLE_RATE = 44100; // 采样率public void playTone(double frequencyHz, int durationMs) {// 1. 计算所需样本数int numSamples = (int)(durationMs * SAMPLE_RATE / 1000.0);short[] buffer = new short[numSamples];double angularFrequency = 2 * Math.PI * frequencyHz / SAMPLE_RATE;// 2. 生成正弦波样本for (int i = 0; i < numSamples; i++) {double sample = Math.sin(i * angularFrequency);buffer[i] = (short)(sample * Short.MAX_VALUE); // 16位PCM}// 3. 配置AudioTrackAudioTrack audioTrack = new AudioTrack(new AudioAttributes.Builder().setUsage(AudioAttributes.USAGE_MEDIA).setContentType(AudioAttributes.CONTENT_TYPE_MUSIC).build(),new AudioFormat.Builder().setSampleRate(SAMPLE_RATE).setEncoding(AudioFormat.ENCODING_PCM_16BIT).setChannelMask(AudioFormat.CHANNEL_OUT_MONO).build(),buffer.length * 2, // 缓冲区大小（字节）AudioTrack.MODE_STATIC,AudioManager.AUDIO_SESSION_ID_GENERATE);// 4. 播放音频audioTrack.write(buffer, 0, buffer.length);audioTrack.play();// 5. 释放资源（实际使用需异步处理）new Thread(() -> {try {Thread.sleep(durationMs);} catch (InterruptedException e) {e.printStackTrace();}audioTrack.stop();audioTrack.release();}).start();}}int play = 0;@SuppressLint("ClickableViewAccessibility")@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);EdgeToEdge.enable(this);setContentView(R.layout.activity_main23);ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);return insets;});ToneGenerator ge = new ToneGenerator();ImageView image = findViewById(R.id.ins_1);// 羽毛图片（拖拽效果）
//        ImageView feather = findViewById(R.id.fea);ImageView clear = findViewById(R.id.clear);SingleTouchView pic1 = findViewById(R.id.pic1);ImageView pic2 = findViewById(R.id.pic2);TextView text = findViewById(R.id.pal_1);Typeface type = Typeface.createFromAsset(getAssets(), "kaishu.TTF");text.setTypeface(type);EditText ed_ = findViewById(R.id.reply);
//        image_2.setImageResource(R.drawable.b_s_5);
//        image_2.setVisibility(VISIBLE);clear.setOnClickListener(v -> {pic1.setVisibility(INVISIBLE);pic2.setVisibility(INVISIBLE);text.setVisibility(INVISIBLE);});image.setOnTouchListener((v1, event) -> {String x = new String(String.valueOf(event.getX()));String y = new String(String.valueOf(event.getY()));Toast.makeText(getApplicationContext(), x, Toast.LENGTH_SHORT).show();Toast.makeText(getApplicationContext(), y, Toast.LENGTH_SHORT).show();//        1、测试：(471,594) +- 25if ((event.getX() > 446) && (event.getX() < 496) && (event.getY() > 569) && (event.getY() < 619)) {text.setText(R.string.line_132);text.setVisibility(VISIBLE);pic1.setImageDrawable(R.drawable.mi_1);pic1.setVisibility(VISIBLE);}
//        2、钢琴：(809,764) +- 25if ((event.getX() > 784) && (event.getX() < 834) && (event.getY() > 739) && (event.getY() < 789)) {text.setText(R.string.line_167);text.setVisibility(VISIBLE);pic2.setImageResource(R.drawable.piano);pic2.setVisibility(VISIBLE);play = 2;}return false;});pic2.setOnTouchListener((v1, event) -> {String x = new String(String.valueOf(event.getX()));String y = new String(String.valueOf(event.getY()));Toast.makeText(getApplicationContext(), x, Toast.LENGTH_SHORT).show();Toast.makeText(getApplicationContext(), y, Toast.LENGTH_SHORT).show();//        1、do：(838,293) +- x +- 15 y +- 30if ((event.getX() > 823) && (event.getX() < 853) && (event.getY() > 278) && (event.getY() < 338)) {ge.playTone(261.63, 800);  // do}
//        2、#do：(879,112) +- x +- 15 y +- 30if ((event.getX() > 864) && (event.getX() < 894) && (event.getY() > 82) && (event.getY() < 142)) {ge.playTone(277.20, 800);  // #do}
//        3、re：(917,293) +- x +- 15 y +- 30if ((event.getX() > 902) && (event.getX() < 932) && (event.getY() > 263) && (event.getY() < 323)) {ge.playTone(293.69, 800);  // re}
//        4、#re：(963,112) +- x +- 15 y +- 30if ((event.getX() > 948) && (event.getX() < 978) && (event.getY() > 82) && (event.getY() < 142)) {ge.playTone(311.16, 800);  // #re}
//        5、mi：(984,293) +- x +- 15 y +- 30if ((event.getX() > 969) && (event.getX() < 999) && (event.getY() > 263) && (event.getY() < 323)) {ge.playTone(329.68, 800);  // re}
//        6、fa：(1056,293) +- x +- 15 y +- 30if ((event.getX() > 1041) && (event.getX() < 1071) && (event.getY() > 263) && (event.getY() < 323)) {ge.playTone(349.29, 800);  // re}
//        7、#fa：(1094,112) +- x +- 15 y +- 30if ((event.getX() > 1079) && (event.getX() < 1109) && (event.getY() > 82) && (event.getY() < 142)) {ge.playTone(370.08, 800);  // #re}
//        8、sol：(1124,293) +- x +- 15 y +- 30if ((event.getX() > 1109) && (event.getX() < 1139) && (event.getY() > 263) && (event.getY() < 323)) {ge.playTone(392.10, 800);  // re}
//        9、#sol：(1161,112) +- x +- 15 y +- 30if ((event.getX() > 1146) && (event.getX() < 1176) && (event.getY() > 82) && (event.getY() < 142)) {ge.playTone(415.43, 800);  // #re}
//        10、la：(1200,293) +- x +- 15 y +- 30if ((event.getX() > 1185) && (event.getX() < 1215) && (event.getY() > 263) && (event.getY() < 323)) {ge.playTone(440.145, 800);  // re}
//        11、bsi：(1247,112) +- x +- 15 y +- 30if ((event.getX() > 1232) && (event.getX() < 1262) && (event.getY() > 82) && (event.getY() < 142)) {ge.playTone(466.33, 800);  // #re}
//        12、si：(1266,293) +- x +- 15 y +- 30if ((event.getX() > 1251) && (event.getX() < 1281) && (event.getY() > 263) && (event.getY() < 323)) {ge.playTone(494.08, 800);  // re}
//        13、do：(1343,293) +- x +- 15 y +- 30if ((event.getX() > 1328) && (event.getX() < 1358) && (event.getY() > 263) && (event.getY() < 323)) {ge.playTone(523.26, 800);  // re}return false;});}
}

二、音阶原理（高中数学内容）

标准的C大调，中央C（do-4）的频率为261.63赫兹（更标准的参考为la-4，频率为440赫兹）。从中央C上行一个八度，到达do-5，频率翻倍，即为523.26赫兹。从do-4上行至do-5，中间共12个半音（do, #do, re, #re, mi, fa, #fa, sol, #sol, la, bsi, si），呈等比数列递增，公比为2开12次根号。如何求得这个公比值呢？我们利用Python，类似牛顿·拉夫森法，简便地得到近似值。代码如下：

import mathstart = 1
while math.pow(start, 12) <= 1.999999:start += 0.0001print(start)
print(math.pow(1.0594999999999934, 12))
print(math.pow(1.0595, 12))