所以我想创建的是一个显示图像按钮的活动。图像按钮的背景指向可绘制文件夹中的xml,以显示用于聚焦和点击的不同图片。这一切都很好。我的主要活动中有音乐,可以循环播放。默认情况下,图像按钮被设置为说音乐开。我想要发生的是当按钮被点击时,主要声音将暂停,按钮背景将改变为不同的xml可绘制布局,即音乐关闭。当再次点击时,音乐将从停止的位置恢复,并再次切换回音乐开启。媒体播放器和如果语句
我遇到的一个问题是暂停主要声音。因为我是Android新手,可以在我的主要活动中引用的媒体播放器变量在不同的活动中进行更改?另外,在我的选项活动中,我有两个if语句,点击图像按钮以检查声音是否正在播放或不在,然后根据声音是哪一个来暂停或恢复音乐。我不知道如何做第二条陈述,但我认为第一条我认为可能是对的。
对不起,我尝试做很多不同的事情,但我试图分解它。此外,当我开始选择活动时,我正在关闭力量,并且我会将所有内容包括在主要活动中,因为这是我建立mainSound的地方。感谢你给与我的帮助。
MainActivity:
package com.crazycastles;
import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.WindowManager;
import android.widget.ImageButton;
public class MainActivity extends Activity implements OnClickListener {
/** Called when the activity is first created. */
private MediaPlayer mainSound;
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) { if ((keyCode == KeyEvent.KEYCODE_BACK)) { //Back key pressed //Things to Do
if(mainSound!= null) { mainSound.pause(); mainSound=null; } finish(); return true; } return super.onKeyDown(keyCode, event); }
public void onCreate(Bundle savedInstanceState) {
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mainSound = MediaPlayer.create(MainActivity.this, R.raw.mainscreen);
mainSound.setLooping(true);
mainSound.start();
//CREATE BUTTON 1 & SOUND
final MediaPlayer buttonSound = MediaPlayer.create(
MainActivity.this, R.raw.swords);
ImageButton button1 = (ImageButton) findViewById(R.id.button1);
button1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
buttonSound.start();
startActivity(new Intent(MainActivity.this,
button1Activity.class));
}
});
ImageButton multiplayerbutton = (ImageButton) findViewById(R.id.multiplayerbutton);
multiplayerbutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
buttonSound.start();
startActivity(new Intent(MainActivity.this,
multiplayerbuttonActivity.class));
}
});
ImageButton optionsbutton = (ImageButton) findViewById(R.id.optionsbutton);
optionsbutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
buttonSound.start();
startActivity(new Intent(MainActivity.this,
optionsActivity.class));
}
});
ImageButton creditbutton = (ImageButton) findViewById(R.id.creditbutton);
creditbutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
buttonSound.start();
startActivity(new Intent(MainActivity.this,
creditsActivity.class));
}
});
ImageButton exitbutton = (ImageButton) findViewById(R.id.exitbutton);
exitbutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
buttonSound.start();
finish();
mainSound.stop();
System.exit(0);
}
});
//END OF BUTTON1 & SOUND
}
public void onClick(View v) {
// TODO Auto-generated method stub
}
}
optionsActivity:
package com.crazycastles;
import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.ImageButton;
public class optionsActivity extends Activity {
/** Called when the activity is first created. */
ImageButton musicbutton, musicbutton2;
private MediaPlayer mainSound;
final MediaPlayer buttonSound = MediaPlayer.create(
optionsActivity.this, R.raw.swords);
@Override
public void onCreate(Bundle savedInstanceState) {
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
super.onCreate(savedInstanceState);
setContentView(R.layout.options);
final ImageButton musicbutton = (ImageButton) findViewById(R.id.musicbutton);
musicbutton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if(mainSound.isPlaying()) {
musicbutton.setBackgroundResource(R.drawable.musicbutton2);
buttonSound.start();
mainSound.pause();
}
}
});
}
}
的logcat:
01-15 16:10:55.059: E/AndroidRuntime(7319): FATAL EXCEPTION: main
01-15 16:10:55.059: E/AndroidRuntime(7319): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.crazycastles/com.crazycastles.optionsActivity}: java.lang.NullPointerException
01-15 16:10:55.059: E/AndroidRuntime(7319): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2659)
01-15 16:10:55.059: E/AndroidRuntime(7319): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2753)
01-15 16:10:55.059: E/AndroidRuntime(7319): at android.app.ActivityThread.access$2500(ActivityThread.java:129)
01-15 16:10:55.059: E/AndroidRuntime(7319): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2107)
01-15 16:10:55.059: E/AndroidRuntime(7319): at android.os.Handler.dispatchMessage(Handler.java:99)
01-15 16:10:55.059: E/AndroidRuntime(7319): at android.os.Looper.loop(Looper.java:143)
01-15 16:10:55.059: E/AndroidRuntime(7319): at android.app.ActivityThread.main(ActivityThread.java:4701)
01-15 16:10:55.059: E/AndroidRuntime(7319): at java.lang.reflect.Method.invokeNative(Native Method)
01-15 16:10:55.059: E/AndroidRuntime(7319): at java.lang.reflect.Method.invoke(Method.java:521)
01-15 16:10:55.059: E/AndroidRuntime(7319): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
01-15 16:10:55.059: E/AndroidRuntime(7319): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
01-15 16:10:55.059: E/AndroidRuntime(7319): at dalvik.system.NativeStart.main(Native Method)
01-15 16:10:55.059: E/AndroidRuntime(7319): Caused by: java.lang.NullPointerException
01-15 16:10:55.059: E/AndroidRuntime(7319): at android.content.ContextWrapper.getResources(ContextWrapper.java:80)
01-15 16:10:55.059: E/AndroidRuntime(7319): at android.media.MediaPlayer.create(MediaPlayer.java:641)
01-15 16:10:55.059: E/AndroidRuntime(7319): at com.crazycastles.optionsActivity.<init>(optionsActivity.java:17)
01-15 16:10:55.059: E/AndroidRuntime(7319): at java.lang.Class.newInstanceImpl(Native Method)
01-15 16:10:55.059: E/AndroidRuntime(7319): at java.lang.Class.newInstance(Class.java:1429)
01-15 16:10:55.059: E/AndroidRuntime(7319): at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
01-15 16:10:55.059: E/AndroidRuntime(7319): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2651)
谢谢,我会看看。 – 2012-01-16 19:18:07
@Zach J.祝你好运 – arufian 2012-01-16 19:32:24