Easy fix that worked for me (after trying some of these other suggestion). My logcat was sitting blank in a separate window (on my second screen). Just had to drag the Logcat tab back to it's original place in the debug panel next to the Debugger and Console tabs, and VOILA... it began immediately updating and showing all processes verbose. So (If your logcat is anywhere outside of the debugger panel (i.e. the logcat tab isn't sitting nested alongside the debugger and console tab) then it won't receive updates and will sit there blankly. Don't know if this is an issue with older versions of Android Studio. But again, easy to try and if it works... it works!!

在android Studio应用程序中，您需要单击调试应用程序选项(Shift+f9)以调试模式运行并启用LogCat。

全核解决方案。只有在尝试了所有其他方法后才使用这个方法，因为这将删除您所有的设置和首选项，以及存储的图像和所有使您的模拟器运行的东西，直到您重新安装和重新配置。以我为例，这两个步骤都花了大约20分钟，因为除了使用Darcula外，我没有进行太多自定义。

删除你的。androidstudiobeta配置文件目录

对于linux用户，这可以在/home/[username]/下找到。AndroidStudioBeta 对于windows用户，我不确定。在我看来，关于它的文件相当模糊。可能在C:\Users[你的用户]\Application Data下面

检查它是否工作，如果不能，然后重新安装SDK。

相当激烈，但我尝试了这个页面上的所有其他东西，连接设备，没有过滤器，重新启动服务，这个页面上的所有东西，它就是不工作。

我刚把它修好了。在DDMS显示的最右边寻找恢复Devices Logcat视图和ADB视图的小图标。

When the DDMS first came up with both the "ADB Logs" and the "Devices | logcat" tab showing. The "Devices | logcat" is the one that should be showing the device output, but was blank. Somehow I managed to hide one or the other of those tabs, I forget exactly how. But, off to the right there was a tiny icon that said "Restore ADB" view, and I clicked it and it came up. Then there was another tiny icon that said "Restore Devices logcat view". I clicked that, and all of a sudden it appeared and was showing the device output again.

如果同时使用多个版本的adb, Logcat可能会失败。一个在Android Studio，一个在终端。

你可能有不同版本的adb: sudo apt-get install android-tools-adb将创建/usr/bin/adb Android SDK包含{Android - SDK}/platform-tools/adb， 或者从创建/host/linux-x86/bin/adb的AOSP构建的输出

要查看这个问题是否影响到你，使用“Help -> Show Log in Files”打开idea.log，并寻找类似于“Initializing adb using:/home/repkap11/android-sdk/platform-tools/adb”的行。将此路径与终端中的“which adb”进行比较。如果它们不匹配，这个问题就会影响到您。

Android studio寻找{Android -sdk}/platform-tools/adb，并不关心你的PATH。我用符号链接替换了android-sdk中的adb版本，但简单地“sudo apt-get remove android-tools-adb”也可以。

需要连续两次按“Alt+6”重新启动logcat窗口。这样它就会显示日志输出。

问题主要发生在调试模式。