Screen Lock password in android

I am develop开发者_运维百科ing an application where I have to change the screen lock password on a button click,can anybody tell me how can I do this.

If you are talking about the unlock pass word set in the device settings by the user then the answer is you can't.

If an application could change the unlock password/pattern without user interaction then these security features would be mostly useless. A rogue application could in theory lock the user out of their own device if this were possible.

Edit: if your aim is not to change this value without interaction but just to send them to the correct settings page. You might be able to do that some how. You'd want to look into what intents you can use to start the Settings Activities. But if you are developing this application for use by the general public I would strongly recommend you rethink having try to do anything with the users security settings. As a user if an application prompted and then sent me to the security settings page with the intention of having me change something in there I would immediately uninstall it.

Edit 2: I've never seen it until just now so I don't know for sure what they used to achieve that. Since it states that must be android 2.2+ though I would assume they are using the Device Administration APIs The docs seem to indicate that it can "Prompt user to set a new password." Which I would think means that it is just going to start the settings activity for them. It is not actually changing the password value by itself. This whole API is subject to user activation also. So even if you get installed on a device the user must explicitly "activate" your app before it is able to make use of any of the admin APIs

I am sure the only way this is possible is if you signed your APK with the device key. This way it could access API's that are limited to system applications. This isn't possible for a normal app, only one that is baked into a custom ROM or device manufacturer ROM when building Android from source.

I do not exactly understand what you are trying to do. If you wish to change the lock screen password programmatically, and your'e application is A device administration than you can call: resetPassword method of DevicePolicyManager like this for example:

m_policyManager.resetPassword("bla bla", DevicePolicyManager.PASSWORD_QUALITY_SOMETHING);