我遇到了这篇文章中描述的类似问题。那里没有答案 - android intro screen error when add to 8 screen, but not error if 4 screen
但是，我的中有 4 张欢迎幻灯片，应用程序只显示其中 2 张。第三个只是有一个错误。我的代码:
public class WelcomeActivity extends AppCompatActivity {
private ViewPager viewPager;
private MyViewPagerAdapter myViewPagerAdapter;
private LinearLayout dotsLayout;
private TextView[] dots;
private int[] layouts;
private Button btnSkip, btnNext;
private PrefManager prefManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Checking for first time launch - before calling setContentView()
prefManager = new PrefManager(this);
if (!prefManager.isFirstTimeLaunch()) {
launchHomeScreen();
finish();
}
// Making notification bar transparent
if (Build.VERSION.SDK_INT >= 21) {
getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
}
setContentView(R.layout.activity_welcome);
viewPager = (ViewPager) findViewById(R.id.view_pager);
dotsLayout = (LinearLayout) findViewById(R.id.layoutDots);
btnSkip = (Button) findViewById(R.id.btn_skip);
btnNext = (Button) findViewById(R.id.btn_next);
// layouts of all welcome sliders
// add few more layouts if you want
layouts = new int[]{
R.layout.welcome_slide1,
R.layout.welcome_slide2,
R.layout.welcome_slide3,
R.layout.welcome_slide4};
// adding bottom dots
addBottomDots(0);
// making notification bar transparent
changeStatusBarColor();
myViewPagerAdapter = new MyViewPagerAdapter();
viewPager.setAdapter(myViewPagerAdapter);
viewPager.addOnPageChangeListener(viewPagerPageChangeListener);
btnSkip.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
launchHomeScreen();
}
});
btnNext.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// checking for last page
// if last page home screen will be launched
int current = getItem(+1);
if (current < layouts.length) {
// move to next screen
viewPager.setCurrentItem(current);
} else {
launchHomeScreen();
}
}
});
}
private void addBottomDots(int currentPage) {
dots = new TextView[layouts.length];
int[] colorsActive = getResources().getIntArray(R.array.array_dot_active);
int[] colorsInactive = getResources().getIntArray(R.array.array_dot_inactive);
dotsLayout.removeAllViews();
for (int i = 0; i < dots.length; i++) {
dots[i] = new TextView(this);
dots[i].setText(Html.fromHtml("•"));
dots[i].setTextSize(35);
dots[i].setTextColor(colorsInactive[currentPage]);
dotsLayout.addView(dots[i]);
}
if (dots.length > 0)
dots[currentPage].setTextColor(colorsActive[currentPage]);
}
private int getItem(int i) {
return viewPager.getCurrentItem() + i;
}
private void launchHomeScreen() {
prefManager.setFirstTimeLaunch(false);
startActivity(new Intent(WelcomeActivity.this, MainActivity.class));
finish();
}
// viewpager change listener
ViewPager.OnPageChangeListener viewPagerPageChangeListener = new ViewPager.OnPageChangeListener() {
@Override
public void onPageSelected(int position) {
addBottomDots(position);
// changing the next button text 'NEXT' / 'GOT IT'
if (position == layouts.length - 1) {
// last page. make button text to GOT IT
btnNext.setText(getString(R.string.start));
btnSkip.setVisibility(View.GONE);
} else {
// still pages are left
btnNext.setText(getString(R.string.next));
btnSkip.setVisibility(View.VISIBLE);
}
}
@Override
public void onPageScrolled(int arg0, float arg1, int arg2) {
}
@Override
public void onPageScrollStateChanged(int arg0) {
}
};
/**
* Making notification bar transparent
*/
private void changeStatusBarColor() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
Window window = getWindow();
window.addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
window.setStatusBarColor(Color.TRANSPARENT);
}
}
/**
* View pager adapter
*/
public class MyViewPagerAdapter extends PagerAdapter {
private LayoutInflater layoutInflater;
public MyViewPagerAdapter() {
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View view = layoutInflater.inflate(layouts[position], container, false);
container.addView(view);
return view;
}
@Override
public int getCount() {
return layouts.length;
}
@Override
public boolean isViewFromObject(View view, Object obj) {
return view == obj;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
View view = (View) object;
container.removeView(view);
}
}
}
错误:
07-01 11:17:24.961 10911-10911/com.google.android.gms.samples.vision.ocrreader E/InputEventReceiver: Exception dispatching input event.
07-01 11:17:24.961 10911-10911/com.google.android.gms.samples.vision.ocrreader E/MessageQueue-JNI: Exception in MessageQueue callback: handleReceiveCallback
07-01 11:17:24.967 10911-10911/com.google.android.gms.samples.vision.ocrreader E/MessageQueue-JNI: java.lang.ArrayIndexOutOfBoundsException: length=2; index=2
at com.google.android.gms.samples.vision.ocrreader.WelcomeActivity.addBottomDots(WelcomeActivity.java:107)
at com.google.android.gms.samples.vision.ocrreader.WelcomeActivity.access$300(WelcomeActivity.java:21)
at com.google.android.gms.samples.vision.ocrreader.WelcomeActivity$3.onPageSelected(WelcomeActivity.java:130)
at android.support.v4.view.ViewPager.dispatchOnPageSelected(ViewPager.java:1941)
at android.support.v4.view.ViewPager.scrollToItem(ViewPager.java:680)
at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:664)
at android.support.v4.view.ViewPager.onTouchEvent(ViewPager.java:2257)
at android.view.View.dispatchTouchEvent(View.java:9314)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2592)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2283)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2598)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2297)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2598)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2297)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2598)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2297)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2598)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2297)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2598)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2297)
at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2598)
at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2297)
at com.android.internal.policy.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2430)
at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent_aroundBody0(PhoneWindow.java:1762)
at com.android.internal.policy.PhoneWindow$AjcClosure1.run(PhoneWindow.java:1)
at android.view.PhoneWindowAO.ajc$around$android_view_PhoneWindowAO$4$99ce526bproceed(PhoneWindowAO.aj:149)
at android.view.PhoneWindowAO.ajc$around$android_view_PhoneWindowAO$4$99ce526b(PhoneWindowAO.aj:153)
at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1762)
at android.app.Activity.dispatchTouchEvent(Activity.java:2807)
at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:68)
at com.android.internal.policy.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2391)
at android.view.View.dispatchPointerEvent(View.java:9534)
at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4422)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4288)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3739)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3792)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3758)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3766)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3739)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3792)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3758)
at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3885)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3766)
at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3942)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3739)
at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3792)
at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3758)
at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3766)
at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3739)
at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6146)
at android.view
最佳答案
关于您的问题
dots[i].setTextColor(colorsInactive[currentPage]);
您从资源中获取colorsInactive
int[] colorsInactive = getResources().getIntArray(R.array.array_dot_inactive);
您可以在src/main/res/arrays.xml或类似名称的文件中找到它们。此处定义的数组的名称为 array_dot_[in]active，并且仅包含两个元素。为了使您的代码正常工作，您需要向这些数组添加两种以上的颜色，或者更改代码本身以反射(reflect)只有两种颜色的事实。
一种方法是使用 %2 或 &1 产生相同的值(如果是偶数则为 0，如果为奇数则为 1) :
dots[i].setTextColor(colorsInactive[currentPage & 1]);
关于java - 介绍屏幕中的 ArrayIndexOutOfBoundsException，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/51121701/