until recently my logcat has been fine but all of the sudden whenever i try to view it in eclipse it just keeps clearing itself whenever anything is displayed making it impossible to read. viewing it in the adb works but I never bother with that since it is just such a pain to read and find anything you are looking for.
is there a way to fix this problem?
It will show one line before erasing it to show the next one? Just click the verbose button again.
The Logcat messages were simple getting cleared because the buffer had run out of space (receiving too many new messages), which is a simple setting change in Eclipse.
To fix, go to Window > Preferences > Android > LogCat
and increase the limit for "Maximum number of LogCat messages to buffer". Set it to 0 for unlimited size, or a really big number. But keep in mind, anything below 10000 fills up real fast.
Been answered already: Eclipse Android - Logcat Clearing too Fast
There's a workaround for this bug. Click active mode button (usually verbose), choose another device from device list and choose previous device again. It will restore all logcat messages.
LogCat is really annoying for this. In Ubuntu, I found the following works really well:
Open a terminal and type adb logcat | grep MYINFO
This will only show adb messages filtered by the MYINFO string.
So, you can code something like:
Log.v("MYINFO", "x" + x_value + ", etc...");
This is such a relief to use. A life saver! See this for more info.
You may find sometimes the logcat buffer repeats previous logs on starting again. To overcome this, type
adb logcat -c
来源：https://stackoverflow.com/questions/5794796/logcat-in-eclipse-keeps-auto-clearing