所有这些都无济于事，我的日志猫功能失常。

After a lot of angry searching I found a solution that seems to work: 1. Make sure logcat itself is working (use DDMS from Tools->Android) and if it does close DDMS window again 2. Now go to Tab 5 (Debug), there select Logcat (this is not the same logcat as in Window 6!) 3. The window is empty just like Window 6, but now start a debugging run. For me logcat in the Debug window now started to show all the stuff again! Also when normally running the application the Debug->logcat view is still functional while the Tool Window #6 "logcat" is disfunctional as before

这是一个黑客，但是它会导致正常的logcat行为，突出显示您调试和开发所需的行和语法。 从现在开始，您需要通过调试窗口访问它。

检查log标记中是否有空格。如果标签由空格组成，则删除空格，然后运行。您将能够查看日志。

今天也遇到了同样的问题。

显然，我也运行了eclipse，所有的logcat输出都被重定向到eclipse。由于日志只能在一个地方显示，请确保您没有运行多个调试器。

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!!

在我的例子中，它通过TCP连接断开，即使设备出现了。

调用

adb connect <device ip>

重启logcat OK。

确保您导入了正确的类

import android.util.Log;