求助：Android Studio 3.1及更早版本日志无法正常显示

Hey there, I’ve run into this exact log display issue multiple times across different Android Studio versions, so I feel your pain! Let’s walk through some proven fixes that should get your logs showing up properly again:

• Double-check Logcat Filter Settings
  The most common culprit is a misconfigured filter.

  • Make sure the "Show only selected application" dropdown is actually picking your app’s process (it should display your app’s package name). If it’s set to a different process or a custom filter that’s too strict, your logs will get hidden.
  • Temporarily switch the log level to "Verbose"—sometimes higher levels like Info or Debug might exclude logs you’re expecting.

• Restart Logcat (and Android Studio)
  Don’t underestimate the power of a quick reset:

  • Click the circular arrow Restart button in the Logcat toolbar to refresh the log stream.
  • If that doesn’t work, fully close Android Studio, kill any leftover studio.exe/studio.sh processes in your task manager, and restart the IDE. The Logcat daemon can get stuck and needs a fresh start.

• Invalidate Caches and Restart
  Corrupted cache files often cause weird IDE glitches:

  • Go to File > Invalidate Caches... > Invalidate and Restart. This clears out stale data and forces Android Studio to rebuild its indexes, which frequently resolves log display issues.

• Reset ADB Connection
  A flaky ADB link can block log transmission:

  • Open Android Studio’s Terminal and run these commands:

    adb kill-server
    adb start-server
    

  • Run adb devices to confirm your emulator/device is listed and recognized. If not, reconnect the device or restart the emulator.

• Check Device/Emulator Log Restrictions
  Some devices or emulators limit log output by default:

  • For emulators: Use the latest system image, and try wiping emulator data (AVD Manager > Select your emulator > Wipe Data) to reset its state.
  • For physical devices: Go to Settings > Developer Options > Debugging, ensure your app is selected as the "Select debug app", and enable "Disable adb authorization timeout" if you’re facing connection drops.

• Verify Your App’s Logging Code
  Sometimes the issue isn’t with Android Studio—it’s with your logging implementation:

  • Double-check you’re using Log.d(), Log.i(), etc., with valid tags and messages. Avoid Log.v() if your log level is set higher than Verbose.
  • If you’re using ProGuard/R8, add these rules to proguard-rules.pro to prevent log statements from being stripped:

    -keepclassmembers class * {
        public static android.util.Log *;
    }
    

• Update Android Studio and SDK Tools
  Outdated versions have known Logcat bugs:

  • Go to Help > Check for Updates (Windows/Linux) or Android Studio > Check for Updates (macOS) to install the latest patches.
  • Also, update SDK Platform Tools via the SDK Manager—this fixes compatibility issues with newer devices/emulators.

内容的提问来源于stack exchange，提问作者Imran Hakeem