How to provision my iOS device for development?

I have the following files with me.

aps_d开发者_运维百科ev_cert_key.p12 aps_developer_identity.cer and apxxx_dev.mobileprovision

Same set exists for distribution too. Now, I went to Keychain access, dragged key file onto "Keys" and cer file onto "Certificates". I followed the instruction in this post How to install the iPhone application on my iPod touch

But Build & Run is not working for me, as I get "The Identity xxxxyyyyzzzzzxxxxx doesn't match any valid certificate/private key pair in default keychain"

1. Double click the "aps_dev_cert_key.p12", it should be password protected. Enter password, it will automatically install the cert and key to KeyChain.

2. Double click the "apxxx_dev.mobileprovision", it should be automatically installed to xCode, which can be viewed in Organizer.

3. Open Settings for your project>> Code sign: select the cert that was just added.

4. Build to Device should install it to your iphone, provided the Iphone's UDID was added in the "apxxx_dev.mobileprovision".

hope that helps.