java - 与声音关联的应用程序飞出模拟器

Question

我需要制作一个应用程序，以便在我点击图片时发出声音。我用 Java (Android Studio) 编写。

package com.example.project_1; 
import android.media.MediaPlayer;
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;

private ImageView img1, img2;
private MediaPlayer sound1, sound2;

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

  img1=(ImageView)findViewById(R.id.image1);
  img2=(ImageView)findViewById(R.id.image2);

  sound1=MediaPlayer.create(this, R.raw.sn1);
  sound2=MediaPlayer.create(this, R.raw.sn2);

  imageClick();
}

public void imageClick() {
  img1.setOnClickListener(
        new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SoundPlay(sound1);
            }
        }
  );

  img2.setOnClickListener(
        new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SoundPlay(sound2);
            }
        }
  );
}

public void SoundPlay(MediaPlayer allsounds) {
  allsounds.start();
}

}

代码已编译，但是当您在模拟器中单击图像时，应用程序崩溃了。在日志中找到它:

2019-06-01 21:15:08.408 13431-13431/? E/ample.project_: Unknown bits set in runtime_flags: 0x8000 
2019-06-01 21:15:08.798 13431-13453/? E/vndksupport: Could not load /vendor/lib/egl/libGLES_emulation.so from sphal namespace: dlopen failed: library "/vendor/lib/egl/libGLES_emulation.so" not found. 
2019-06-01 21:15:08.798 13431-13453/? E/libEGL: load_driver(/vendor/lib/egl/libGLES_emulation.so): unknown
2019-06-01 21:15:09.798 13431-13452/com.example.project_1 E/EGL_emulation: tid 13452: eglQueryString(923): error 0x3008 (EGL_BAD_DISPLAY)
2019-06-01 21:15:17.712 13431-13447/com.example.project_1 E/MediaPlayerNative: error (1, -2147483648) 
2019-06-01 21:15:17.715 13431-13431/com.example.project_1 E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.project_1, PID: 13431 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.media.MediaPlayer.start()' on a null object reference at 
com.example.project_1.MainActivity.SoundPlay(MainActivity.java:51) at 
com.example.project_1.MainActivity$2.onClick(MainActivity.java:43) at 
android.view.View.performClick(View.java:7251) at 
android.view.View.performClickInternal(View.java:7228) at 
android.view.View.access$3500(View.java:802) at 
android.view.View$PerformClick.run(View.java:27843) at 
android.os.Handler.handleCallback(Handler.java:883) at 
android.os.Handler.dispatchMessage(Handler.java:100) at 
android.os.Looper.loop(Looper.java:214) at 
android.app.ActivityThread.main(ActivityThread.java:7116) at 
java.lang.reflect.Method.invoke(Native Method) at
com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) at 
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:925)

Answer 1

我不熟悉Android开发，但在Java中，我们使用ActionListener

格式是这样的。

private variableName = new DataType("params");
variableName.addActionListener(
    new methodName());

然后将该对象添加到 JPanel 或其他东西上...

同样，我不了解 Android，但这就是它在 Java 中的实现方式。所以把它和一小撮盐一起吃。