[英]Android E/Trace(627): error opening trace file: No such file or directory (2)
[英]Android - error opening trace file: No such file or directory
我得到一個奇怪的錯誤列表,有些看似斷開連接,但我無法分辨,因為我甚至無法將我的應用程序加載到調試。 這是一個非常簡單的應用程序,一個廣播組中的3個單選按鈕,每個按鈕都會觸發一首不同的歌曲。
我將首先發布我的Manifest,我的活動文件和布局,然后發布錯誤日志。
表現:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.cis298.lab2"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:label = "@string/app_name"
android:name = ".LayoutActivity">
<intent-filter >
<action android:name = "android.intent.action.MAIN" />
<category android:name = "android.intent.category.LAUNCHER" />
</intent-filter>
></activity>
</application>
</manifest>
LayoutActivity:
package com.cis298.lab2;
import java.io.IOException;
import com.cis298.lab2.R;
import android.app.Activity;
import android.os.Bundle;
import android.media.MediaPlayer;
import android.widget.RadioGroup;
public class LayoutActivity extends Activity {
int song;
MediaPlayer mediaplayer = MediaPlayer.create(this, song);
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.layout);
try {
mediaplayer.prepare();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
RadioGroup radgrp = (RadioGroup) findViewById(R.id.radiogroup);
radgrp.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
switch (checkedId){
case R.id.dance:
song = R.raw.redalert;
mediaplayer.start();
break;
case R.id.rap:
song = R.raw.cannedheat;
break;
case R.id.rock:
song = R.raw.movmou8105;
break;}
}
});
}
}
布局:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<RadioGroup
android:id="@+id/radiogroup"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:orientation="vertical" >
<RadioButton
android:id="@+id/rock"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Play Rock" />
<RadioButton
android:id="@+id/rap"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Play Rap"
android:checked="true"/>
<RadioButton
android:id="@+id/dance"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Play Dance"
android:textAlignment="center" />
</RadioGroup>
</RelativeLayout>
日志:
02-21 20:34:05.044:D / AndroidRuntime(322):關閉VM 02-21 20:34:05.044:W / dalvikvm(322):threadid = 1:線程退出未捕獲異常(組= 0x4001d800)02 -21 20:34:05.094:E / AndroidRuntime(322):FATAL EXCEPTION:main 02-21 20:34:05.094:E / AndroidRuntime(322):java.lang.RuntimeException:無法實例化活動ComponentInfo {com.cis298 .lab2 / com.cis298.lab2.LayoutActivity}:java.lang.NullPointerException 02-21 20:34:05.094:E / AndroidRuntime(322):at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585)02- 21 20:34:05.094:E / AndroidRuntime(322):在android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)02-21 20:34:05.094:E / AndroidRuntime(322):在android.app。 ActivityThread.access $ 2300(ActivityThread.java:125)02-21 20:34:05.094:E / AndroidRuntime(322):at android.app.ActivityThread $ H.handleMessage(ActivityThread.java:2033)02-21 20:34 :05.094:E / AndroidRuntime(322):在android.os.Handler.dispatchMessage(Handler.java:99)02-21 20 :34:05.094:E / AndroidRuntime(322):在android.os.Looper.loop(Looper.java:123)02-21 20:34:05.094:E / AndroidRuntime(322):在android.app.ActivityThread。 main(ActivityThread.java:4627)02-21 20:34:05.094:E / AndroidRuntime(322):at java.lang.reflect.Method.invokeNative(Native Method)02-21 20:34:05.094:E / AndroidRuntime (322):at java.lang.reflect.Method.invoke(Method.java:521)02-21 20:34:05.094:E / AndroidRuntime(322):at com.android.internal.os.ZygoteInit $ MethodAndArgsCaller。 run(ZygoteInit.java:868)02-21 20:34:05.094:E / AndroidRuntime(322):at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)02-21 20:34: 05.094:E / AndroidRuntime(322):at dalvik.system.NativeStart.main(Native Method)02-21 20:34:05.094:E / AndroidRuntime(322):引起:java.lang.NullPointerException 02-21 20: 34:05.094:E / AndroidRuntime(322):在android.content.ContextWrapper.getResources(ContextWrapper.java:80)02-21 20:34:05.094:E / AndroidRuntime(322):在android.media.MediaPlayer.create (MediaPlayer.java:641) 02-21 20:34:05.094:E / AndroidRuntime(322):at com.cis298.lab2.LayoutActivity。(LayoutActivity.java:15)02-21 20:34:05.094:E / AndroidRuntime(322):at java .lang.Class.newInstanceImpl(Native Method)02-21 20:34:05.094:E / AndroidRuntime(322):at java.lang.Class.newInstance(Class.java:1429)02-21 20:34:05.094: E / AndroidRuntime(322):在android.app.Instrumentation.newActivity(Instrumentation.java:1021)02-21 20:34:05.094:E / AndroidRuntime(322):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java) :2577)02-21 20:34:05.094:E / AndroidRuntime(322):... 11更多
任何幫助將不勝感激。
嘗試移動mediaplayer = MediaPlayer.create(this, song);
到onCreate()
里面。
由於活動在onCreate()
之前沒有完全初始化,這可能是NPE的原因。
但是 ,下一個問題是您創建的MediaPlayer的歌曲最初為0
(當它是實例變量時,int的默認值為0
)。 因此,如果移動MediaPlayer.create
解決此 NPE,則下一個錯誤將是無法找到資源。 因此,一旦song
保持有用的東西,就調用MediaPlayer.create
。
也許這樣的事情會起作用。
public class LayoutActivity extends Activity {
int song;
MediaPlayer mediaPlayer;
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.layout);
RadioGroup radgrp = (RadioGroup) findViewById(R.id.radiogroup);
radgrp.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(RadioGroup group, int checkedId) {
switch (checkedId){
case R.id.dance:
song = R.raw.redalert;
break;
case R.id.rap:
song = R.raw.cannedheat;
break;
case R.id.rock:
song = R.raw.movmou8105;
break;
}
mediaplayer = MediaPlayer.create(LayoutActivity.this, song);
try {
mediaplayer.prepare();
mediaplayer.start();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
}
}
如果歌曲沒有在其他任何地方使用,你可以將它保持在onCheckedChanged()
的范圍內。
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