问题描述
我每次打电话getResources在我的主要活动是导致错误和应用程序被强制退出。这也发生如果我叫getApplicationContext()。getResources(),甚至在ECLIPS一个全新的项目。我是否需要在调用之前做什么?在AVD错误与Android 2.1和LG GW620与OpenEtna(2.1)
every time I call getResources in my main activity it results in an error and the app is forced to quit. This also happens if I call getApplicationContext().getResources() and even in a totally new project in Eclips. Do I need to do anything before the call? Error on AVD with Android 2.1 and LG GW620 with OpenEtna (2.1)
MainActivity.java:
MainActivity.java:
package com.robin.blatest;
import android.app.Activity;
import android.content.res.Resources;
import android.os.Bundle;
public class MainActivity extends Activity {
Resources res = this.getResources();
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
的Manifest.xml:
Manifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.robin.blatest"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="7" />
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".MainActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
LogCat中:
LogCat:
W/dalvikvm( 229): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
E/AndroidRuntime( 229): Uncaught handler: thread main exiting due to uncaught exception
E/AndroidRuntime( 229): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.robin.blatest/com.robin.blatest.MainActivity}: java.lang.NullPointerException
E/AndroidRuntime( 229): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2417)
E/AndroidRuntime( 229): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
E/AndroidRuntime( 229): at android.app.ActivityThread.access$2200(ActivityThread.java:119)
E/AndroidRuntime( 229): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
E/AndroidRuntime( 229): at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime( 229): at android.os.Looper.loop(Looper.java:123)
E/AndroidRuntime( 229): at android.app.ActivityThread.main(ActivityThread.java:4363)
E/AndroidRuntime( 229): at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime( 229): at java.lang.reflect.Method.invoke(Method.java:521)
E/AndroidRuntime( 229): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
E/AndroidRuntime( 229): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
E/AndroidRuntime( 229): at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime( 229): Caused by: java.lang.NullPointerException
E/AndroidRuntime( 229): at android.content.ContextWrapper.getResources(ContextWrapper.java:80)
E/AndroidRuntime( 229): at com.robin.blatest.MainActivity.<init>(MainActivity.java:9)
E/AndroidRuntime( 229): at java.lang.Class.newInstanceImpl(Native Method)
E/AndroidRuntime( 229): at java.lang.Class.newInstance(Class.java:1479)
E/AndroidRuntime( 229): at android.app.Instrumentation.newActivity(Instrumentation.java:1021)
E/AndroidRuntime( 229): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2409)
E/AndroidRuntime( 229): ... 11 more
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修改:加code
推荐答案
您不能做
Resources res = this.getResources();
在字段声明。这是空在这一点!
in the field declaration. It's null at that point!
放入的onCreate
代替。
您会做这样的事情:
private Resources res = null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
res = this.getResources();
}
如果你想要一个包含数据的字段。
If you wanted a field containing that data.
但它只是那么容易做到 this.getResources()
当您需要它。
But it's just as easy to do this.getResources()
whenever you need it.
这篇关于的getResource错误的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!