在Android上，如果你的 应用程序有一段时间响应不够灵敏，系统会向用户显示一个对话框，这个对话框称作应用程序无响应(ANR：Application Not Responding)对话框。那么，anr 使用方法是什么?

anr如何定位

如果开发机器上出现问题，我们可以通过查看/data/anr/traces.txt即可，最新的ANR信息在最开始部分。我们从stacktrace中即可找到出问题的具体行数。本例中问题出现在MainActivity.java 27行，因为这里调用了Thread.sleep方法。

root@htc_m8tl:/ # cat /data/anr/traces.txt | more

----- pid 30307 at 2015-05-30 14:51:14 -----

Cmd line: com.example.androidyue.bitmapdemo

JNI: CheckJNI is off; workarounds are off; pins=0; globals=272

DALVIK THREADS:

(mutexes: tll=0 tsl=0 tscl=0 ghl=0)

"main" prio=5 tid=1 TIMED_WAIT

| group="main" sCount=1 dsCount=0 obj=0x416eaf18 self=0x416d8650

| sysTid=30307 nice=0 sched=0/0 cgrp=apps handle=1074565528

| state=S schedstat=( 0 0 0 ) utm=5 stm=4 core=3

at java.lang.VMThread.sleep(Native Method)

at java.lang.Thread.sleep(Thread.java:1044)

at java.lang.Thread.sleep(Thread.java:1026)

at com.example.androidyue.bitmapdemo.MainActivity$1.run(MainActivity.java:27)

at android.app.Activity.runOnUiThread(Activity.java:4794)

at com.example.androidyue.bitmapdemo.MainActivity.onResume(MainActivity.java:33)

at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1282)

at android.app.Activity.performResume(Activity.java:5405)

如果是线上版本引起的，Google Play后台有相关的数据可以帮助查看分析并解决问题。

anr细致分析

提问: BroadcastReceiver过了60秒居然没有ANR? 现场代码如下

public class NetworkReceiver extends BroadcastReceiver{

private static final String LOGTAG = "NetworkReceiver";

@Override

public void onReceive(Context context, Intent intent) {

Log.i(LOGTAG, "onReceive intent=" + intent);

try {

Thread.sleep(60000);

} catch (InterruptedException e) {

e.printStackTrace();

}

Log.i(LOGTAG, "onReceive end");

}

}

回答：实际上已经发生了ANR，只是没有进行对话框弹出而已。这种ANR就是background ANR，即后台程序的ANR，我们可以通过过滤日志验证

adb logcat | grep "NetworkReceiver|ActivityManager|WindowManager"

I/NetworkReceiver( 4109): onReceive intent=Intent { act=android.net.conn.CONNECTIVITY_CHANGE flg=0x8000010 cmp=com.example.androidyue.bitmapdemo/.NetworkReceiver (has extras) }

I/ActivityManager( 462): No longer want com.android.exchange (pid 1054): empty #17

I/NetworkReceiver( 4109): onReceive end

W/BroadcastQueue( 462): Receiver during timeout: ResolveInfo{5342dde4 com.example.androidyue.bitmapdemo.NetworkReceiver p=0 o=0 m=0x108000}

E/ActivityManager( 462): ANR in com.example.androidyue.bitmapdemo

E/ActivityManager( 462): Reason: Broadcast of Intent { act=android.net.conn.CONNECTIVITY_CHANGE flg=0x8000010 cmp=com.example.androidyue.bitmapdemo/.NetworkReceiver (has extras) }

E/ActivityManager( 462): Load: 0.37 / 0.2 / 0.14

E/ActivityManager( 462): CPU usage from 26047ms to 0ms ago:

E/ActivityManager( 462): 0.4% 58/adbd: 0% user + 0.4% kernel / faults: 1501 minor

E/ActivityManager( 462): 0.3% 462/system_server: 0.1% user + 0.1% kernel

E/ActivityManager( 462): 0% 4109/com.example.androidyue.bitmapdemo: 0% user + 0% kernel / faults: 6 minor

E/ActivityManager( 462): 1.5% TOTAL: 0.5% user + 0.9% kernel + 0% softirq

E/ActivityManager( 462): CPU usage from 87ms to 589ms later:

E/ActivityManager( 462): 1.8% 58/adbd: 0% user + 1.8% kernel / faults: 30 minor

E/ActivityManager( 462): 1.8% 58/adbd: 0% user + 1.8% kernel

E/ActivityManager( 462): 4% TOTAL: 0% user + 4% kernel

W/ActivityManager( 462): Killing ProcessRecord{5326d418 4109:com.example.androidyue.bitmapdemo/u0a10063}: background ANR

I/ActivityManager( 462): Process com.example.androidyue.bitmapdemo (pid 4109) has died.

除了日志，我们还可以根据前面提到的查看traces.txt文件。