ViewPager快速滑动导致IndexOutOfBoundsException错误

Question

我有一个带有Fragment的ViewPager。当我尝试移动ViewPager时，它能够正常工作。但是，如果我快速滑动，它会给我以下异常。

03-25 11:01:44.901: E/AndroidRuntime(20880): FATAL EXCEPTION: main
03-25 11:01:44.901: E/AndroidRuntime(20880): Process: com.sph.wanbaoandroid, PID: 20880
03-25 11:01:44.901: E/AndroidRuntime(20880): java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
03-25 11:01:44.901: E/AndroidRuntime(20880):    at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at java.util.ArrayList.get(ArrayList.java:308)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.support.v4.view.ViewPager.performDrag(ViewPager.java:2076)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.support.v4.view.ViewPager.onTouchEvent(ViewPager.java:1999)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at com.sph.wb.pdf.controller.ViewPagerWithTapGestreDetection.onTouchEvent(ViewPagerWithTapGestreDetection.java:42)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.View.dispatchTouchEvent(View.java:8281)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2471)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2194)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2477)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2209)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2477)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2209)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2477)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2209)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2477)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2209)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2477)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2209)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2332)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1616)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.app.Activity.dispatchTouchEvent(Activity.java:2665)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2280)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.View.dispatchPointerEvent(View.java:8489)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4890)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:4741)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4295)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4349)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4318)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:4429)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4326)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:4486)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4295)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:4349)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:4318)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:4326)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:4295)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:6705)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:6584)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6555)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:6520)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:6785)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.java:176)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl.doConsumeBatchedInput(ViewRootImpl.java:6758)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(ViewRootImpl.java:6804)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:813)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.Choreographer.doCallbacks(Choreographer.java:613)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.Choreographer.doFrame(Choreographer.java:581)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:799)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.os.Handler.handleCallback(Handler.java:733)
03-25 11:01:44.901: E/AndroidRuntime(20880):    at android.os.Handler.dispatchMessage(Han

- Komali perera

---

你尝试过添加 viewPager.setOffscreenPageLimit(x); 吗？其中 x 是您在 pager 中拥有的总页面数。 - Gary Bak

看起来你的适配器没有页面。你有将项目设置到适配器中吗？请粘贴代码。 - Bharatesh

Answer 1

扩展ViewPager并覆盖onTouchEvent和onInterceptTouchEvent，以忽略当前项目和ViewPager的子项计数均为0的情况。

@Override
public boolean onTouchEvent(MotionEvent ev) {
    if (getCurrentItem() == 0 && getChildCount() == 0) {
        return false;
    }

    return super.onTouchEvent(ev);
}

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    if (getCurrentItem() == 0 && getChildCount() == 0) {
        return false;
    }

    return super.onInterceptTouchEvent(ev);
}

- mojochicken

Answer 2

根据上面的答案，获取完整的SafeViewPager类：

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.viewpager.widget.ViewPager;

public class SafeViewPager extends ViewPager {

    public SafeViewPager(@NonNull Context context) {
        super(context);
    }

    public SafeViewPager(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    public boolean performClick() {
        return super.performClick();
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (getCurrentItem() <= 0 && getChildCount() <= 0) {
            return false;
        }
        if (event.getAction() == MotionEvent.ACTION_UP) {
            performClick();
        }
        return super.onTouchEvent(event);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent event) {
        if (getCurrentItem() <= 0 && getChildCount() <= 0) {
            return false;
        }
        return super.onInterceptTouchEvent(event);
    }
}

- Sergio