11

1、Activity中报异常之后导致应用崩溃吗？

A: 肯定会发生崩溃啊，自己上手一实验，惊奇的发现ActivityA启动ActivityB后，ActivityB抛异常后，ActivityA居然还活着？这是什么情况？
经过一番百度发现，这是Activity的崩溃恢复
首先要知道ActivityB报错之后，该App的进程绝壁会被Kill掉的,这是默认的异常处理器，看finally

  private static class UncaughtHandler implements Thread.UncaughtExceptionHandler {
        public void uncaughtException(Thread t, Throwable e) {
            try {
                // Don't re-enter -- avoid infinite loops if crash-reporting crashes.
                if (mCrashing) return;
                mCrashing = true;

                if (mApplicationObject == null) {
                    Clog_e(TAG, "*** FATAL EXCEPTION IN SYSTEM PROCESS: " + t.getName(), e);
                } else {
                    StringBuilder message = new StringBuilder();
                    message.append("FATAL EXCEPTION: ").append(t.getName()).append("\n");
                    final String processName = ActivityThread.currentProcessName();
                    if (processName != null) {
                        message.append("Process: ").append(processName).append(", ");
                    }
                    message.append("PID: ").append(Process.myPid());
                    Clog_e(TAG, message.toString(), e);
                }

                // Try to end profiling. If a profiler is running at this point, and we kill the
                // process (below), the in-memory buffer will be lost. So try to stop, which will
                // flush the buffer. (This makes method trace profiling useful to debug crashes.)
                if (ActivityThread.currentActivityThread() != null) {
                    ActivityThread.currentActivityThread().stopProfiling();
                }

                // Bring up crash dialog, wait for it to be dismissed
                ActivityManagerNative.getDefault().handleApplicationCrash(
                        mApplicationObject, new ApplicationErrorReport.CrashInfo(e));
            } catch (Throwable t2) {
                if (t2 instanceof DeadObjectException) {
                    // System process is dead; ignore
                } else {
                    try {
                        Clog_e(TAG, "Error reporting crash", t2);
                    } catch (Throwable t3) {
                        // Even Clog_e() fails!  Oh well.
                    }
                }
            } finally {
                // Try everything to make sure this process goes away.
                Process.killProcess(Process.myPid());
                System.exit(10);
            }
        }
    }

系统会重新新建一个进程，仅将栈顶的Activity进行恢复，调用onCreate（），onRestoreSavaInstance()等等一系列操作。

PS:如果Activity运行在其他进程当中，发生崩溃，并不会导致主进程的崩溃。还是见finally中代码。。。。

2、为什么要用Glide，Glide的优势

我TM只会用啊。。。。
Glide支持三级缓存，支持加载Gif，bitmap为RGB_565,占用内存较小
三级缓存：

• 内存缓存
  使用LRUCache算法，底层实现使用LinkedHashMap，LinkedHashMap在HashMap的基础上扩展了一个双向链表来记录顺序，顺序可选择是插入顺序还是访问顺序。
• 硬盘缓存
• 网络获取