Android获取状态栏高度给出java.lang.ExceptionInInitializerError

Question

其他信息（下面的原始问题）

在评论部分中关注@ρяσѕρєяK建议后，我在另一个文件（SizeNotifierRelativeLayout.java）上收到相同的错误，错误发生在第44行，即super.onLayout(changed, l, t, r, b);。该文件和logcat的代码如下：

SizeNotifierRelativeLayout.java

package com.app.name.widgets;

import android.content.Context;
import android.graphics.Rect;
import android.view.View;
import android.widget.RelativeLayout;

import com.app.name.AndroidUtilities;


public class SizeNotifierRelativeLayout extends RelativeLayout {

    private Rect rect = new Rect();
    public SizeNotifierRelativeLayoutDelegate delegate;

    public abstract interface SizeNotifierRelativeLayoutDelegate {
        public abstract void onSizeChanged(int keyboardHeight);
    }

    public SizeNotifierRelativeLayout(Context context) {
        super(context);
    }

    public SizeNotifierRelativeLayout(Context context, android.util.AttributeSet attrs) {
        super(context, attrs);
    }

    public SizeNotifierRelativeLayout(Context context, android.util.AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);
        if (delegate != null) {
            View rootView = this.getRootView();
            int usableViewHeight = rootView.getHeight() - AndroidUtilities.statusBarHeight - AndroidUtilities.getViewInset(rootView);
            this.getWindowVisibleDisplayFrame(rect);
            int keyboardHeight = usableViewHeight - (rect.bottom - rect.top);
            delegate.onSizeChanged(keyboardHeight);
        }
    }
}

logcat的

10-15 09:09:57.918  23530-23530/? W/System.err﹕ at     com.app.name.widgets.SizeNotifierRelativeLayout.onLayout(SizeNotifierRelativeLayout.java:44)
10-15 09:09:57.927  23530-23530/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.NullPointerException
        at android.widget.AbsListView.obtainView(AbsListView.java:2247)
        at android.widget.ListView.makeAndAddView(ListView.java:1849)
        at android.widget.ListView.fillDown(ListView.java:678)
        at android.widget.ListView.fillFromTop(ListView.java:739)
        at android.widget.ListView.layoutChildren(ListView.java:1664)
        at android.widget.AbsListView.onLayout(AbsListView.java:2050)
        at android.view.View.layout(View.java:14243)
        at android.view.ViewGroup.layout(ViewGroup.java:4490)
        at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1021)
        at com.app.name.widgets.SizeNotifierRelativeLayout.onLayout(SizeNotifierRelativeLayout.java:44)
        at android.view.View.layout(View.java:14243)
        at android.view.ViewGroup.layout(ViewGroup.java:4490)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
        at android.view.View.layout(View.java:14243)
        at android.view.ViewGroup.layout(ViewGroup.java:4490)
        at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1670)
        at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1528)
        at android.widget.LinearLayout.onLayout(LinearLayout.java:1441)
        at android.view.View.layout(View.java:14243)
        at android.view.ViewGroup.layout(ViewGroup.java:4490)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
        at android.view.View.layout(View.java:14243)
        at android.view.ViewGroup.layout(ViewGroup.java:4490)
        at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1670)
        at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1528)
        at android.widget.LinearLayout.onLayout(LinearLayout.java:1441)
        at android.view.View.layout(View.java:14243)
        at android.view.ViewGroup.layout(ViewGroup.java:4490)
        at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
        at android.view.View.layout(View.java:14243)
        at android.view.ViewGroup.layout(ViewGroup.java:4490)
        at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2230)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1994)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1181)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4942)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:776)
        at android.view.Choreographer.doCallbacks(Choreographer.java:579)
        at android.view.Choreographer.doFrame(Choreographer.java:548)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:762)
        at android.os.Handler.handleCallback(Handler.java:800)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:194)
        at android.app.ActivityThread.main(ActivityThread.java:5370)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:525)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
        at dalvik.system.NativeStart.main(Native Method)

原始问题 - ＆gt; 我有一个状态栏获取高度函数，它给了我一个

  

FATAL EXCEPTION：main java.lang.ExceptionInInitializerError

MyActivity调用

时设置错误

AndroidUtilities.statusBarHeight = getStatusBarHeight();

功能对应错误：

  

at com.app.name.AndroidUtilities。（AndroidUtilities.java:31）

是

density = App.getInstance().getResources().getDisplayMetrics().density;

由于我对Android和Java相对较新，我希望能指出我所缺少的内容。谢谢！

MyActivity.java

package com.app.name;

import com.app.name.widgets.SizeNotifierRelativeLayout;

public class MyActivity extends ActionBarActivity implements ISideNavigationCallback, SizeNotifierRelativeLayout.SizeNotifierRelativeLayoutDelegate, NotificationCenter.NotificationCenterDelegate {

    private SizeNotifierRelativeLayout sizeNotifierRelativeLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.my_layout);

        AndroidUtilities.statusBarHeight = getStatusBarHeight();

        sizeNotifierRelativeLayout = (SizeNotifierRelativeLayout) findViewById(R.id.chat_layout);
        sizeNotifierRelativeLayout.delegate = this;

        NotificationCenter.getInstance().addObserver(this, NotificationCenter.emojiDidLoaded);
    }

    /**
     * Get the system status bar height
     * @return
     */
    public int getStatusBarHeight() {
        int result = 0;
        int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
        if (resourceId > 0) {
            result = getResources().getDimensionPixelSize(resourceId);
        }
        return result;
    }
}

App.java

package com.app.name;

import android.app.Application;
import android.os.Handler;

public class App extends Application {

    private static App Instance;
    public static volatile Handler applicationHandler = null;

    @Override
    public void onCreate() {
        super.onCreate();

        Instance=this;

        applicationHandler = new Handler(getInstance().getMainLooper());

        NativeLoader.initNativeLibs(App.getInstance());

    }

    public static App getInstance()
    {
        return Instance;
    }
}

AndroidUtilities.java

package com.app.name;

public class AndroidUtilities {

    public static float density = 1;
    public static int statusBarHeight = 0;
    public static Point displaySize = new Point();

    static {
        density = App.getInstance().getResources().getDisplayMetrics().density;
        checkDisplaySize();
    }
}

logcat的

10-15 07:57:41.119  15076-15076/? W/System.err? at com.app.name.MyActivity.onCreate(MyActivity.java:197)
10-15 07:57:41.130  15076-15076/? W/System.err? at com.app.name.AndroidUtilities.<clinit>(AndroidUtilities.java:31)
10-15 07:57:41.145  15076-15076/? E/AndroidRuntime? FATAL EXCEPTION: main
    java.lang.ExceptionInInitializerError
            at com.app.name.MyActivity.onCreate(MyActivity.java:197)
            at android.app.Activity.performCreate(Activity.java:5122)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1150)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2315)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2403)
            at android.app.ActivityThread.access$600(ActivityThread.java:165)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1373)
            at android.os.Handler.dispatchMessage(Handler.java:107)
            at android.os.Looper.loop(Looper.java:194)
            at android.app.ActivityThread.main(ActivityThread.java:5370)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:525)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at com.app.name.AndroidUtilities.<clinit>(AndroidUtilities.java:31)
            at com.app.name.MyActivity.onCreate(MyActivity.java:197)
            at android.app.Activity.performCreate(Activity.java:5122)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1150)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2315)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2403)
            at android.app.ActivityThread.access$600(ActivityThread.java:165)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1373)
            at android.os.Handler.dispatchMessage(Handler.java:107)
            at android.os.Looper.loop(Looper.java:194)
            at android.app.ActivityThread.main(ActivityThread.java:5370)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:525)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
            at dalvik.system.NativeStart.main(Native Method)