ANR：输入调度超时 - 从 URL 创建位图答案

【问题标题】：ANR: Input dispatching timed out - Creating a Bitmap from an URLANR：输入调度超时 - 从 URL 创建位图
【发布时间】：2018-10-16 21:26:47
【问题描述】：

在我的 Android 应用程序中，我正在从图像 URL 创建位图。下面是我编写的从图像 URL 创建位图的代码--

 public static Bitmap getBitmapFromURL(String src)
    {
        try
        {
            StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
            StrictMode.setThreadPolicy(policy);

            URL url = new URL(src);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true);
            connection.connect();
            InputStream input = connection.getInputStream();
            Bitmap myBitmap = BitmapFactory.decodeStream(input);
            return myBitmap;
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }

我的应用程序在 Play-store 上，并且此代码影响了少数设备，因为它们出现“输入调度超时”ANR。以下是我从 Google Play 控制台的“ANR 和崩溃”部分获得的 ANR 详细信息--

"输入调度超时（等待发送非按键事件，因为触摸的窗口尚未完成对 500.0 毫秒前交付给它的某些输入事件的处理。等待队列长度：60。等待队列头年龄：10502.8ms。）“

以下是来自 Google Play 控制台的完整日志--

"main" prio=5 tid=1 Native
  | group="main" sCount=1 dsCount=0 obj=0x75a2c598 self=0xa4e84400
  | sysTid=522 nice=0 cgrp=default sched=0/0 handle=0xa7d13534
  | state=S schedstat=( 0 0 0 ) utm=114 stm=42 core=1 HZ=100
  | stack=0xbe467000-0xbe469000 stackSize=8MB
  | held mutexes=
  #00  pc 0000000000048cb4  /system/lib/libc.so (__ppoll+20)
  #01  pc 000000000001cf3f  /system/lib/libc.so (poll+46)
  #02  pc 0000000000012cb7  /system/lib/libjavacrypto.so (???)
  #03  pc 000000000000f24b  /system/lib/libjavacrypto.so (???)
  #04  pc 000000000000e5cd  /system/framework/arm/boot-conscrypt.oat (Java_com_android_org_conscrypt_NativeCrypto_SSL_1read__JLjava_io_FileDescriptor_2Lcom_android_org_conscrypt_NativeCrypto_00024SSLHandshakeCallbacks_2_3BIII+192)
  at com.android.org.conscrypt.NativeCrypto.SSL_read (Native method)
  at com.android.org.conscrypt.OpenSSLSocketImpl$SSLInputStream.read (OpenSSLSocketImpl.java:761)
- locked <0x06eb358f> (a java.lang.Object)
  at com.android.okhttp.okio.Okio$2.read (Okio.java:142)
  at com.android.okhttp.okio.AsyncTimeout$2.read (AsyncTimeout.java:218)
  at com.android.okhttp.okio.RealBufferedSource.indexOf (RealBufferedSource.java:312)
  at com.android.okhttp.okio.RealBufferedSource.indexOf (RealBufferedSource.java:306)
  at com.android.okhttp.okio.RealBufferedSource.readUtf8LineStrict (RealBufferedSource.java:202)
  at com.android.okhttp.internal.http.HttpConnection.readResponse (HttpConnection.java:210)
  at com.android.okhttp.internal.http.HttpTransport.readResponseHeaders (HttpTransport.java:81)
  at com.android.okhttp.internal.http.HttpEngine.readNetworkResponse (HttpEngine.java:960)
  at com.android.okhttp.internal.http.HttpEngine.readResponse (HttpEngine.java:836)
  at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute (HttpURLConnectionImpl.java:480)
  at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponse (HttpURLConnectionImpl.java:422)
  at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getInputStream (HttpURLConnectionImpl.java:256)
  at com.android.okhttp.internal.huc.DelegatingHttpsURLConnection.getInputStream (DelegatingHttpsURLConnection.java:210)
  at com.android.okhttp.internal.huc.HttpsURLConnectionImpl.getInputStream (HttpsURLConnectionImpl.java)
  at come.xyz.myapp.util.AppHelper.getBitmapFromURL (AppHelper.java:66)
  at come.xyz.myapp.Adapters.ScratchersAdapter.instantiateItem (ScratchersAdapter.java:706)
  at android.support.v4.view.ViewPager.addNewItem (ViewPager.java:1004)
  at android.support.v4.view.ViewPager.populate (ViewPager.java:1218)
  at android.support.v4.view.ViewPager.populate (ViewPager.java:1086)
  at android.support.v4.view.ViewPager.setAdapter (ViewPager.java:534)
  at come.xyz.myapp.widgets.InfiniteViewPager.setAdapter (InfiniteViewPager.java:40)
  at come.xyz.myapp.Fragments.DailyScratchersFragment.updateAdapter (DailyScratchersFragment.java:965)
  at come.xyz.myapp.Fragments.DailyScratchersFragment.onCaughtContent (DailyScratchersFragment.java:750)
  at come.xyz.coresdk.CoreLibrary.onCaughtContent (CoreLibrary.java:591)
  at come.xyz.coresdk.asynctasks.CatchScratcherSetTask.onPostExecute (CatchScratcherSetTask.java:82)
  at come.xyz.coresdk.asynctasks.CatchScratcherSetTask.onPostExecute (CatchScratcherSetTask.java:22)
  at android.os.AsyncTask.finish (AsyncTask.java:660)
  at android.os.AsyncTask.-wrap1 (AsyncTask.java)
  at android.os.AsyncTask$InternalHandler.handleMessage (AsyncTask.java:677)
  at android.os.Handler.dispatchMessage (Handler.java:102)
  at android.os.Looper.loop (Looper.java:154)
  at android.app.ActivityThread.main (ActivityThread.java:6317)
  at java.lang.reflect.Method.invoke! (Native method)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run (ZygoteInit.java:872)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:762)

之前在 stackoverflow 上针对同一问题发布了几个问题，但我发现没有一个问题对我有用。如果我可以提供有关此问题的更多信息，请告诉我。谢谢。

【问题讨论】：

标签： android

【解决方案1】：

我相信您正在主线程上下载图像，这会导致 ANR，我相信您需要在后台线程中进行，如 asynctask 或使用这些 3rd 方之一 https://github.com/bumptech/glide 或 http://square.github.io/picasso/

【讨论】：

【解决方案2】：

可能是下面一行导致问题

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);

不是通过这种方法做网络功能，而是创建一个AsyncTask，同样的，ANR的产生可能是因为过程太长，所以不要启用srickmode，而是使用AsyncTask

【讨论】：

我明白你在说什么，我会尝试同样的方法并让你知道状态。谢谢。
这两行用于记录线程中的所有内容，请查看developer.android.com/reference/android/os/…
我曾经在UI线程中使用StrictMode策略进行网络调用，但有时会导致ANR，所以我将其更改为AsyncTask，对于下载图像最好使用Picasso或Glide ,, 省去了很多代码，效率更高

【解决方案3】：

实际上将“从 URL 创建位图”代码放入 Asynctask 解决了我的问题。下面是我的代码--

public class GetBitmapTask extends AsyncTask<String, Void, Bitmap>
{
    @Override
    protected Bitmap doInBackground(String... urls)
    {
        Bitmap map = null;
        for (String url : urls)
        {
            map = createBitmapFromURL(url);
        }
        return map;
    }

    // Sets the Bitmap returned by doInBackground
    @Override
    protected void onPostExecute(Bitmap resultBitmap)
    {

    }


    public Bitmap createBitmapFromURL(String src)
    {
        try
        {
            URL url = new URL(src);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true);
            connection.connect();
            InputStream input = connection.getInputStream();
            Bitmap myBitmap = BitmapFactory.decodeStream(input);
            return myBitmap;
        }
        catch (Exception e)
        {
            e.printStackTrace();
            return null;
        }
    }
}

下面是我如何称呼这个任务--

Bitmap mBitmap = new GetBitmapTask().execute(strImgUrl).get();

【讨论】：