私はアプリに5つのボタンが含まれており、各ボタンが異なるビデオビューを開きます.コードを作成すると、下に赤いマークがあります:(new MediaController(this))
それから抜け出すためのアドバイスをお願いします、私はアンドロイド開発の初心者です、
ありがとう
適用後の UPDATE が : (new MediaController(this)) に変更され、別のエラーが発生する
私のコード:
複数ボタン クラス :
public class MultipleButton extends Activity {
String night;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void handleClick(View v){
//Create an intent to start the new activity.
Intent intent = new Intent();
intent.setClass(this,My_videos.class);
intent.putExtra("video",night);
startActivity(intent);
}
}
My_videos CLASS :ストロング テキスト
public class My_videos extends Activity {
private Button button;
private VideoView vid;
String night;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.video);
initializeVideoViews(); }
private void initializeVideoViews() {
String night = getIntent().getStringExtra("video");
if(night.equalsIgnoreCase("button1")){
button = (Button) findViewById(R.id.button1);
button.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
vid =(VideoView) findViewById(R.id.videoView1);
vid.setVideoURI(Uri.parse("android.resource://" +
getPackageName() +"/"+R.raw.a));
vid.setMediaController(new MediaController(My_videos.this));
vid.requestFocus();
vid.start();
}
}); }
else if(night.equalsIgnoreCase("button2")){
button = (Button) findViewById(R.id.button2);
button.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
vid = (VideoView) findViewById(R.id.videoView1);
vid.setVideoURI(Uri.parse("android.resource://" +
getPackageName() +"/"+R.raw.b));
vid.setMediaController(new MediaController(My_videos.this));
vid.requestFocus();
}
});}
else if(night.equalsIgnoreCase("button3")){
button = (Button) findViewById(R.id.button3);
button.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
vid = (VideoView) findViewById(R.id.videoView1);
vid.setVideoURI(Uri.parse("android.resource://" +
getPackageName() +"/"+R.raw.c));
vid.setMediaController(new MediaController(My_videos.this));
vid.requestFocus();
}
});}
else if(night.equalsIgnoreCase("button4")){
button = (Button) findViewById(R.id.button4);
button.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
vid = (VideoView) findViewById(R.id.videoView1);
vid.setVideoURI(Uri.parse("android.resource://" +
getPackageName() +"/"+R.raw.d));
vid.setMediaController(new MediaController(My_videos.this));
vid.requestFocus();
}
});}
else if(night.equalsIgnoreCase("button5")){
button = (Button) findViewById(R.id.button5);
button.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
vid = (VideoView) findViewById(R.id.videoView1);
vid.setVideoURI(Uri.parse("android.resource://" +
getPackageName() +"/"+R.raw.e));
vid.setMediaController(new MediaController(My_videos.this));
vid.requestFocus();
}
});
}}}
更新: 強いテキスト
ログキャット:
I/Process(25196): Sending signal. PID: 25196 SIG: 9
D/AndroidRuntime(25447): Shutting down VM
W/dalvikvm(25447): threadid=1: thread exiting with uncaught exception (group=0x40015578)
E/AndroidRuntime(25447): FATAL EXCEPTION: main
E/AndroidRuntime(25447): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tsn.dr/com.tsn.dr.My_videos}: java.lang.NullPointerException
E/AndroidRuntime(25447):at android.app.ActivityThread.performLaunchActivity (ActivityThread.java:1651)
E/AndroidRuntime(25447):at android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:1667)
E/AndroidRuntime(25447):at android.app.ActivityThread.access$1500 (ActivityThread.java:117)
E/AndroidRuntime(25447):at android.app.ActivityThread$H.handleMessage (ActivityThread.java:935)
E/AndroidRuntime(25447):at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime(25447):at android.os.Looper.loop(Looper.java:123)
E/AndroidRuntime(25447):at android.app.ActivityThread.main(ActivityThread.java:3687)
E/AndroidRuntime(25447):at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(25447):at java.lang.reflect.Method.invoke(Method.java:507)
E/AndroidRuntime(25447):at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:842)
E/AndroidRuntime(25447):at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:600)
E/AndroidRuntime(25447):at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime(25447): Caused by: java.lang.NullPointerException
E/AndroidRuntime(25447):at com.tsn.dr.My_videos.initializeVideoViews (My_videos.java:31)
E/AndroidRuntime(25447):at com.tsn.dr.My_videos.onCreate(My_videos.java:24)
E/AndroidRuntime(25447):at android.app.Instrumentation.callActivityOnCreate (Instrumentation.java:1047)
E/AndroidRuntime(25447):at android.app.ActivityThread.performLaunchActivity (ActivityThread.java:1615)
E/AndroidRuntime(25447): ... 11 more
マニフェスト.xml:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.tsn.dr"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="8" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:name=".MultipleButton"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".My_videos"
android:label="@string/app_name">
</activity>
</application>
main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:onClick="handleClick"
android:text="Button" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:onClick="handleClick"
android:text="Button" />
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:onClick="handleClick"
android:text="Button" />
<Button
android:id="@+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:onClick="handleClick"
android:text="Button" />
<Button
android:id="@+id/button5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:onClick="handleClick"
android:text="Button" />
</LinearLayout>
video.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<VideoView
android:id="@+id/videoView1"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</LinearLayout>