logcat的：
09-05 19:18:35.166: E/AndroidRuntime(25586): FATAL EXCEPTION: main
09-05 19:18:35.166: E/AndroidRuntime(25586): java.lang.NullPointerException
09-05 19:18:35.166: E/AndroidRuntime(25586): at com.example.eveminingcalculator.UpdatePrices$2.run(UpdatePrices.java:215)
09-05 19:18:35.166: E/AndroidRuntime(25586): at android.os.Handler.handleCallback(Handler.java:615)
09-05 19:18:35.166: E/AndroidRuntime(25586): at android.os.Handler.dispatchMessage(Handler.java:92)
09-05 19:18:35.166: E/AndroidRuntime(25586): at android.os.Looper.loop(Looper.java:137)
09-05 19:18:35.166: E/AndroidRuntime(25586): at android.app.ActivityThread.main(ActivityThread.java:4961)
09-05 19:18:35.166: E/AndroidRuntime(25586): at java.lang.reflect.Method.invokeNative(Native Method) 09-05 19:18:35.166: E/AndroidRuntime(25586): at java.lang.reflect.Method.invoke(Method.java:511)
09-05 19:18:35.166: E/AndroidRuntime(25586): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1004)
09-05 19:18:35.166: E/AndroidRuntime(25586): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:771)
09-05 19:18:35.166: E/AndroidRuntime(25586): at dalvik.system.NativeStart.main(Native Method)
的AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.eveminingcalculator"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="16"
android:targetSdkVersion="18" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".UpdatePrices"
android:configChanges="orientation|keyboardHidden|screenSize"
android:screenOrientation="portrait"
android:label="@string/app_name"
android:theme="@style/FullscreenTheme" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
UpdatePrices.java
package com.example.eveminingcalculator;
import com.example.eveminingcalculator.util.SystemUiHider;
import android.annotation.TargetApi;
import android.app.Activity;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
/**
* An example full-screen activity that shows and hides the system UI (i.e.
* status bar and navigation/system bar) with user interaction.
*
* @see SystemUiHider
*/
public class UpdatePrices extends Activity {
/**
* Whether or not the system UI should be auto-hidden after
* {@link #AUTO_HIDE_DELAY_MILLIS} milliseconds.
*/
private static final boolean AUTO_HIDE = true;
/**
* If {@link #AUTO_HIDE} is set, the number of milliseconds to wait after
* user interaction before hiding the system UI.
*/
private static final int AUTO_HIDE_DELAY_MILLIS = 3000;
/**
* If set, will toggle the system UI visibility upon interaction. Otherwise,
* will show the system UI visibility upon interaction.
*/
private static final boolean TOGGLE_ON_CLICK = true;
/**
* The flags to pass to {@link SystemUiHider#getInstance}.
*/
private static final int HIDER_FLAGS = SystemUiHider.FLAG_HIDE_NAVIGATION;
/**
* The instance of the {@link SystemUiHider} for this activity.
*/
private SystemUiHider mSystemUiHider;
protected void onCreate(Bundle savedInstanceState, ArrayAdapter<CharSequence> Adapter) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_update_prices);
final View controlsView = findViewById(R.id.SaveButtonLayout);
final View contentView = findViewById(R.id.Background);
Spinner ShipSpinner = (Spinner) findViewById(R.id.spinnerShips);
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
R.array.Ships, R.layout.spinner_layout);
adapter.setDropDownViewResource(R.layout.spinner_layout);
ShipSpinner.setAdapter(adapter);
Spinner TurretSpinner = (Spinner) findViewById(R.id.spinnerTurrets);
ArrayAdapter<CharSequence> adapter2 = ArrayAdapter.createFromResource(this,
R.array.Turrets, R.layout.spinner_layout);
adapter2.setDropDownViewResource(R.layout.spinner_layout);
TurretSpinner.setAdapter(adapter2);
Spinner TurretNumSpinner = (Spinner) findViewById(R.id.spinnerTurretNumber);
ArrayAdapter<CharSequence> adapter3 = ArrayAdapter.createFromResource(this,
R.array.NumTurrets, R.layout.spinner_layout);
adapter3.setDropDownViewResource(R.layout.spinner_layout);
TurretNumSpinner.setAdapter(adapter3);
Spinner UpgradesSpinner = (Spinner) findViewById(R.id.spinnerUpgrades);
ArrayAdapter<CharSequence> adapter4 = ArrayAdapter.createFromResource(this,
R.array.Upgrades, R.layout.spinner_layout);
adapter4.setDropDownViewResource(R.layout.spinner_layout);
UpgradesSpinner.setAdapter(adapter4);
Spinner UpgradesNumSpinner = (Spinner) findViewById(R.id.spinnerUpgradesNum);
ArrayAdapter<CharSequence> adapter5 = ArrayAdapter.createFromResource(this,
R.array.NumUpgrades, R.layout.spinner_layout);
adapter5.setDropDownViewResource(R.layout.spinner_layout);
UpgradesNumSpinner.setAdapter(adapter5);
Spinner ImplantSpinner = (Spinner) findViewById(R.id.spinnerImplant);
ArrayAdapter<CharSequence> adapter6 = ArrayAdapter.createFromResource(this,
R.array.Implants, R.layout.spinner_layout);
adapter6.setDropDownViewResource(R.layout.spinner_layout);
ImplantSpinner.setAdapter(adapter6);
Spinner ShipSkillSpinner = (Spinner) findViewById(R.id.spinnerShipSkill);
ArrayAdapter<CharSequence> adapter7 = ArrayAdapter.createFromResource(this,
R.array.SkillLevel, R.layout.spinner_layout);
adapter7.setDropDownViewResource(R.layout.spinner_layout);
ShipSkillSpinner.setAdapter(adapter7);
Spinner MiningSkillSpinner = (Spinner) findViewById(R.id.spinnerMiningSkill);
ArrayAdapter<CharSequence> adapter8 = ArrayAdapter.createFromResource(this,
R.array.SkillLevel, R.layout.spinner_layout);
adapter8.setDropDownViewResource(R.layout.spinner_layout);
MiningSkillSpinner.setAdapter(adapter8);
Spinner AstroSkillSpinner = (Spinner) findViewById(R.id.spinnerAstroSkill);
ArrayAdapter<CharSequence> adapter9 = ArrayAdapter.createFromResource(this,
R.array.SkillLevel, R.layout.spinner_layout);
adapter9.setDropDownViewResource(R.layout.spinner_layout);
AstroSkillSpinner.setAdapter(adapter9);
Spinner IceSkillSpinner = (Spinner) findViewById(R.id.spinnerIceHarvSkill);
ArrayAdapter<CharSequence> adapter10 = ArrayAdapter.createFromResource(this,
R.array.SkillLevel, R.layout.spinner_layout);
adapter10.setDropDownViewResource(R.layout.spinner_layout);
IceSkillSpinner.setAdapter(adapter10);
Spinner DeepCoreSkillSpinner = (Spinner) findViewById(R.id.spinnerDeepCoreSkill);
ArrayAdapter<CharSequence> adapter11 = ArrayAdapter.createFromResource(this,
R.array.SkillLevel, R.layout.spinner_layout);
adapter11.setDropDownViewResource(R.layout.spinner_layout);
DeepCoreSkillSpinner.setAdapter(adapter11);
// Set up an instance of SystemUiHider to control the system UI for
// this activity.
mSystemUiHider = SystemUiHider.getInstance(this, contentView, HIDER_FLAGS);
mSystemUiHider.setup();
mSystemUiHider
.setOnVisibilityChangeListener(new SystemUiHider.OnVisibilityChangeListener() {
// Cached values.
int mControlsHeight;
int mShortAnimTime;
@Override
@TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
public void onVisibilityChange(boolean visible) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
// If the ViewPropertyAnimator API is available
// (Honeycomb MR2 and later), use it to animate the
// in-layout UI controls at the bottom of the
// screen.
if (mControlsHeight == 0) {
mControlsHeight = controlsView.getHeight();
}
if (mShortAnimTime == 0) {
mShortAnimTime = getResources().getInteger(
android.R.integer.config_shortAnimTime);
}
controlsView.animate()
.translationY(visible ? 0 : mControlsHeight)
.setDuration(mShortAnimTime);
} else {
// If the ViewPropertyAnimator APIs aren't
// available, simply show or hide the in-layout UI
// controls.
controlsView.setVisibility(visible ? View.VISIBLE : View.GONE);
}
if (visible && AUTO_HIDE) {
// Schedule a hide().
delayedHide(AUTO_HIDE_DELAY_MILLIS);
}
}
});
// Set up the user interaction to manually show or hide the system UI.
contentView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (TOGGLE_ON_CLICK) {
mSystemUiHider.toggle();
} else {
mSystemUiHider.show();
}
}
});
// Upon interacting with UI controls, delay any scheduled hide()
// operations to prevent the jarring behavior of controls going away
// while interacting with the UI.
findViewById(R.id.buttonCalculateIPH).setOnTouchListener(mDelayHideTouchListener);
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Trigger the initial hide() shortly after the activity has been
// created, to briefly hint to the user that UI controls
// are available.
delayedHide(100);
}
/**
* Touch listener to use for in-layout UI controls to delay hiding the
* system UI. This is to prevent the jarring behavior of controls going away
* while interacting with activity UI.
*/
View.OnTouchListener mDelayHideTouchListener = new View.OnTouchListener() {
@Override
public boolean onTouch(View view, MotionEvent motionEvent) {
if (AUTO_HIDE) {
delayedHide(AUTO_HIDE_DELAY_MILLIS);
}
return false;
}
};
Handler mHideHandler = new Handler();
Runnable mHideRunnable = new Runnable() {
@Override
public void run() {
mSystemUiHider.hide();
}
};
/**
* Schedules a call to hide() in [delay] milliseconds, canceling any
* previously scheduled calls.
*/
private void delayedHide(int delayMillis) {
mHideHandler.removeCallbacks(mHideRunnable);
mHideHandler.postDelayed(mHideRunnable, delayMillis);
}
}
答案 0 :(得分：1)
这就是我正在发生的事情。
您正在致电
super.onCreate(savedInstanceState);，
在你打电话之前调用
mSystemUiHider = SystemUiHider.getInstance(this, contentView, HIDER_FLAGS);
这意味着，机器人OnCreate会调用您OnPostCreate();的电话delayedHide(100);，然后此代码将调用您mSystemUiHider使用的其他方法。请注意，此时，您的mSystemUiHider仍然为空。由于您的onCreate()代码尚未运行。 （我们仍然使用您自己的super.onCreate()方法onCreate()。
而不是让OnPostExecute运行delayedHide(100)或许将其放在onCreate方法的末尾，这样您就知道mSystemUiHider已初始化。