title: Android to set/change/remove Lock Screen PIN, Password or Unlock Pattern programatically
body: <p>I'm working in an android project which is used to secure android device with password.  For that i have to set password programatically. used reference<a href="http://developer.android.com/guide/topics/admin/device-admin.html" rel="nofollow noreferrer">user device administration api</a> and this <a href="https://stackoverflow.com/questions/9724428/how-can-i-set-up-screen-lock-with-a-password-programmatically">example</a> But it throws error(below) :</p>
  
  <pre><code>08-18 02:12:26.888: W/dalvikvm(2600): threadid=1: thread exiting with uncaught       exception (group=0x40a401f8)
  08-18 02:12:26.888: E/AndroidRuntime(2600): FATAL EXCEPTION: main
  08-18 02:12:26.888: E/AndroidRuntime(2600): java.lang.RuntimeException: Unable to start activity ComponentInfo{dilli.passwordtest/dilli.passwordtest.MainActivity}: java.lang.SecurityException: No active admin ComponentInfo{dilli.passwordtest/dilli.passwordtest.MainActivity}
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.app.ActivityThread.access$600(ActivityThread.java:123)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.os.Handler.dispatchMessage(Handler.java:99)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.os.Looper.loop(Looper.java:137)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.app.ActivityThread.main(ActivityThread.java:4429)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at java.lang.reflect.Method.invokeNative(Native Method)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at java.lang.reflect.Method.invoke(Method.java:511)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at dalvik.system.NativeStart.main(Native Method)
  08-18 02:12:26.888: E/AndroidRuntime(2600): Caused by: java.lang.SecurityException: No active admin ComponentInfo{dilli.passwordtest/dilli.passwordtest.MainActivity}
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.os.Parcel.readException(Parcel.java:1327)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.os.Parcel.readException(Parcel.java:1281)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.app.admin.IDevicePolicyManager$Stub$Proxy.setPasswordQuality(IDevicePolicyManager.java:761)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.app.admin.DevicePolicyManager.setPasswordQuality(DevicePolicyManager.java:292)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at dilli.passwordtest.MainActivity.onCreate(MainActivity.java:24)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.app.Activity.performCreate(Activity.java:4465)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     at     android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
  08-18 02:12:26.888: E/AndroidRuntime(2600):     ... 11 more
  </code></pre>
  
  <p>I don't have clear clarification in that. So, Could some buddy please help me. Thanks in advance.</p>