我在布局文件中发现了Null Pointer Exception。
我使用ViewPager因为我发现NullPointerException的原因。
以下是布局的xml代码。
<?xml version="1.0" encoding="utf-8"?>
<com.mindsoulmatter.iaffirmme.ViewPagerParallax xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/viewpager"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#70000000"
android:paddingBottom="2dp"
android:textColor="#D7D6D6" >
<android.support.v4.view.PagerTitleStrip
android:id="@+id/__Weekly_pager_title_strip"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top"
android:background="#70000000"
android:paddingTop="18dp"
android:textColor="#FFFFFF"
android:textSize="26sp" />
<View
android:layout_width="fill_parent"
android:layout_height="1dp"
android:background="#ffffff" />
</com.mindsoulmatter.iaffirmme.ViewPagerParallax>
我在图形布局中遇到以下错误：
java.lang.NullPointerException
Exception details are logged in Window > Show View > Error Log
java.lang.NullPointerException
at android.graphics.Canvas.throwIfCannotDraw(Canvas.java:1083)
at android.graphics.Canvas.drawBitmap(Canvas.java:1201)
at com.mindsoulmatter.iaffirmme.ViewPagerParallax.onDraw(ViewPagerParallax.java:204)
at android.view.View.draw(View.java:14465)
at android.support.v4.view.ViewPager.draw(ViewPager.java:2171)
at android.view.View.draw(View.java:14350)
at android.view.ViewGroup.drawChild(ViewGroup.java:3103)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2940)
at android.view.View.draw(View.java:14348)
at android.view.ViewGroup.drawChild(ViewGroup.java:3103)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2940)
at android.view.View.draw(View.java:14468)
at android.view.View.draw(View.java:14350)
at android.view.ViewGroup.drawChild(ViewGroup.java:3103)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2940)
at android.view.View.draw(View.java:14468)
我可以运行应用程序但是当我打开这个布局时，应用程序会崩溃。
使用以下片段活动调用此布局：
package com.mindsoulmatter.iaffirmme;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.Vector;
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.graphics.Typeface;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.PagerTitleStrip;
import android.support.v4.view.ViewPager;
import android.util.Log;
import android.view.Window;
import android.widget.TextView;
public class Activity_Fragments extends FragmentActivity {
List<Fragment> fragments;
Adapter_ViewPager adapter;
ViewPagerParallax pager;
String restoredText;
private static String[] titles = new String[] { "Custom", "Affirmations",
"Favorites" };
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.adapter_fragment);
RateThisApp.onStart(this);
// Show a dialog if criteria is satisfied
RateThisApp.showRateDialogIfNeeded(this);
overridePendingTransition(R.anim.slide_in_left, R.anim.slide_out_left);
fragments = new Vector<Fragment>();
fragments.add(Fragment.instantiate(this,
Fragment_Affirm_Custom.class.getName()));
fragments.add(Fragment.instantiate(this,
Fragment_Affirm.class.getName()));
fragments.add(Fragment.instantiate(this,
Fragment_Affirm_Favourites.class.getName()));
// registerReceiver(broadcastCoverReceiverpara, new IntentFilter(
// Music_service.BROADCAST_COVERPARALLAX));
SharedPreferences prefs = getApplicationContext().getSharedPreferences(
"udata", MODE_PRIVATE);
this.restoredText = prefs.getString("language", null);
if (restoredText == "english") {
titles = new String[] { "Custom", "Affirmations", "Favorites" };
} else if (restoredText == "spanish") {
titles = new String[] { "Costumbre", "Afirmaciones", "Favoritos " };
} else if (restoredText == "french") {
titles = new String[] { "Coutume", "Affirmations", "Favoris" };
} else {
titles = new String[] { "Custom", "Affirmations", "Favorites" };
}
adapter = new Adapter_ViewPager(super.getSupportFragmentManager(),
fragments, titles);
pager = (ViewPagerParallax) super.findViewById(R.id.viewpager);
pager.set_max_pages(3);
PagerTitleStrip _Title = (PagerTitleStrip) findViewById(R.id.__Weekly_pager_title_strip);
Typeface font = Typeface.createFromAsset(this.getAssets(),
"fonts/julius-sans-one.ttf");
for (int counter = 0; counter < _Title.getChildCount(); counter++) {
if (_Title.getChildAt(counter) instanceof TextView) {
((TextView) _Title.getChildAt(counter)).setTypeface(font);
}
}
/*int arr[] = { R.raw.a1, R.raw.a2, R.raw.a3, R.raw.a4, R.raw.a5,
R.raw.a6, R.raw.a7, R.raw.a8, R.raw.a9, R.raw.a10, R.raw.a11,
R.raw.a12, R.raw.a13, R.raw.a14, R.raw.a15, R.raw.a16,
R.raw.a17, R.raw.a18, R.raw.a19, R.raw.a20, R.raw.a21,
R.raw.a22, R.raw.a23, R.raw.a24, R.raw.a25, R.raw.a26,
R.raw.a27, R.raw.a28, R.raw.a29, R.raw.a30, R.raw.a31,
R.raw.a32, R.raw.a33, R.raw.a34, R.raw.a35, R.raw.a36,
R.raw.a37, R.raw.a38, R.raw.a39, R.raw.a40, R.raw.a41 };*/
int arr[] = { R.raw.a1, R.raw.a2, R.raw.a3, R.raw.a4,R.raw.a5};
int x = (int) (Math.random() * ((4) + 1));
pager.setBackgroundAsset(arr[x]);
// pager.setPageTransformer(true, new ZoomOutPageTransformer());
pager.setAdapter(adapter);
pager.setOffscreenPageLimit(1);
pager.setCurrentItem(1);
}
// private BroadcastReceiver broadcastCoverReceiverpara = new
// BroadcastReceiver() {
// @Override
// public void onReceive(Context context, Intent serviceIntent) {
// pager.setBackgroundAsset(serviceIntent.getStringExtra( "coverpara"));
// }
// };
@Override
public void finish() {
super.finish();
overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_right);
}
}
调用pager.setBackgroundAsset(arr[x])时出错。
任何人都可以帮帮我吗？
答案 0 :(得分：2)
我找到了解决方案。
图像本身存在问题。
有些图像本身已经破碎。
谢谢你们的时间。
答案 1 :(得分：0)
看起来像
int x = (int) (Math.random() * ((4) + 1));
给你错误的数组ID
答案 2 :(得分：0)
自定义View可以使用此方法检测它们是否在布局编辑器（在开发人员工具中）内运行：
View.isInEditMode()
显然，ViewPagerParallax视图不是，因此在布局编辑器中使用非法方法。