Android source code when running on eclipse error

            
Learning to develop Android, when running in eclipse download the source code when prompted following error, it is not know how to do, please help

[2013-12-11 21:38:04 - MediaPlayerProject] Unable to resolve target 'android-4'
[2013-12-11 21:38:24 - MediaPlayerProject] ------------------------------
[2013-12-11 21:38:24 - MediaPlayerProject]! Android Launch
[2013-12-11 21:38:24 - MediaPlayerProject] The connection to adb is down, and a severe error has occured
.[2013-12-11 21:38:24 - MediaPlayerProject] You must restart adb and Eclipse
.[2013-12-11 21:38:24 - MediaPlayerProject] Please ensure that adb is correctly located at 'C: \ Users \ 571864 \ android-sdks \ platform-tools \ adb.exe' and can be executed

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Virtual machine is not connected to it.
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Seems to be, how to solve ah?
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Why is it always being given, depressed dead, the enthusiasm for the program are slowly weakening, why eclipse running on the source, not the wrong, is that wrong, depressed!
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The workaround is to restart the adb and eclipse and android virtual machine
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You must restart adb and Eclipse.
Please ensure that adb is correctly located at 'C: \ Users \ 571864 \ android-sdks \ platform-tools \ adb.exe' and can be executed
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The landlord, note the error message ah!
Make sure you have the sdk and jdk environment variable configuration to
Once configured, open the Task Manager to see if there adb.exe process, any kill, then restart Eclipse
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references, 5th Floor ncepu307 reply:

You must restart adb and Eclipse
.Please ensure that adb is correctly located at 'C: \ Users \ 571864 \ android-sdks \ platform-tools \ adb.exe' and can be executed
.
The landlord, note the error message ah!
Make sure you have the sdk and jdk environment variable configuration to
Once configured, open the Task Manager to see if there adb.exe process, any kill, then restart Eclipse

Right - generally kill abd can be a ~
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Agreed to the fifth floor, or look adb 5037 port has not been occupied
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SDK is not a failure, there is no 'android-4', 1.6 for SDK
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Without this version of the emulator or device
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Today, the beginning rerun tips Could not find ChinaWeather.apk!
How is this going to rebuild it? But I follow online, could not find how rebuild the
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I have often encountered this problem, so I generally solved:
1 restart eclipse
2 Double-click adb.exe
3 confirmed with 360 mobile phone connections intact assistant
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[2013-12-12 11:31:12 - ChinaWeather] ------------------------------
[2013-12-12 11:31:12 - ChinaWeather]! Android Launch
[2013-12-12 11:31:12 - ChinaWeather] adb is running normally
.[2013-12-12 11:31:12 - ChinaWeather] Could not find ChinaWeather.apk
!
This prompted many online methods do not work, how to do. .