no response to setVisibility

Question

Я пытаюсь написать приложение с кнопками, которые вызывают звук, и хотите, чтобы кнопки были видны только при нажатии. Я добавляю метод setVisibility, но когда я нажимаю кнопку, ответа нет.

Мой код:

import android.app.Activity; 
import android.media.MediaPlayer; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Button; 
import android.widget.ImageButton; 
import android.widget.RelativeLayout; 

import static android.view.View.INVISIBLE; 
import static android.view.View.VISIBLE; 

public class MainActivity extends Activity { 

RelativeLayout background; 
ImageButton btn; 
MediaPlayer sound; 

@Override 
protected void onPause() { 
    super.onPause(); 
    sound.release(); 
} 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    sound = MediaPlayer.create(this, R.raw.kick); 
    btn = (ImageButton) findViewById(R.id.btn1); 
    btn.setVisibility(INVISIBLE); 
    btn.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      MediaPlayer mp = MediaPlayer.create(getApplicationContext(), R.raw.kick); 
       btn.setVisibility(VISIBLE); 
      mp.start(); 

     } 
    }); 




} 

} 

XML

<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" 
android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" 
android:paddingBottom="@dimen/activity_vertical_margin" 
tools:context=".MainActivity" 
android:id="@+id/background" 
android:background="@drawable/fuckyou" 
android:orientation="horizontal"> 


<ImageButton 
    android:id="@+id/btn1" 
    android:layout_width="109dp" 
    android:layout_height="89dp" 
    android:scaleType="fitXY" 
    android:layout_marginTop="26dp" 
    android:src="@mipmap/oneeee" 
    android:background="@null" 
    android:contentDescription="@null" 
    android:layout_alignParentTop="true" 
    android:layout_alignParentLeft="true" 
    android:layout_alignParentStart="true" 
    android:layout_marginLeft="1dp" /> 

LogCat показывает следующее:

06-20 02:02:57.249 28473-28473/sp.umavibe.com.sp404 I/art﹕ Not late- enabling -Xcheck:jni (already on) 
06-20 02:02:57.249 28473-28473/sp.umavibe.com.sp404 I/art﹕ Late-enabling JIT 
06-20 02:02:57.251 28473-28473/sp.umavibe.com.sp404 I/art﹕ JIT created with code_cache_capacity=2MB compile_threshold=1000 
06-20 02:02:57.673 28473-28484/sp.umavibe.com.sp404 I/art﹕ Background sticky concurrent mark sweep GC freed 8726(388KB) AllocSpace objects, 0(0B) LOS objects, 0% free, 10MB/10MB, paused 6.293ms total 56.655ms 
06-20 02:02:57.695 28473-28473/sp.umavibe.com.sp404 E/MediaPlayer﹕ Should have subtitle controller already set 
06-20 02:02:57.710 28473-28489/sp.umavibe.com.sp404 D/OpenGLRenderer﹕ Use EGL_SWAP_BEHAVIOR_PRESERVED: true 
06-20 02:02:57.714 28473-28473/sp.umavibe.com.sp404 D/﹕ HostConnection::get() New Host Connection established 0xab1704a0, tid 28473 
06-20 02:02:57.728 28473-28473/sp.umavibe.com.sp404 E/MediaPlayer﹕ Should have subtitle controller already set 
06-20 02:02:57.775 28473-28489/sp.umavibe.com.sp404 D/﹕ HostConnection::get() New Host Connection established 0xab170540, tid 28489 
06-20 02:02:57.804 28473-28489/sp.umavibe.com.sp404 I/OpenGLRenderer﹕ Initialized EGL, version 1.4 
06-20 02:02:57.857 28473-28489/sp.umavibe.com.sp404 W/EGL_emulation﹕ eglSurfaceAttrib not implemented 
06-20 02:02:57.857 28473-28489/sp.umavibe.com.sp404 W/OpenGLRenderer﹕ Failed to set EGL_SWAP_BEHAVIOR on surface 0xab163c00, error=EGL_SUCCESS 

Answer 1

Try - v.setVisibility(View.VISIBLE);

Вы создаете кнопку INVISIBLE, а затем, как она собирается получить событие click. вы должны сделать его видимым для выполнения события щелчка. код -

btn.setVisibilty(View.VISIBLE); 
btn.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      Toast.makeText(MyAndroidAppActivity.this, 
      "ImageButton is clicked!", Toast.LENGTH_SHORT).show(); 
       v.setVisibility(View.INVISIBLE); 

       MediaPlayer mp = MediaPlayer.create(getApplicationContext(), R.raw.kick); 
       mp.start(); 

     } 
}); 

и добавьте следующие строки в layout-

android:clickable="true"