StrictMode Class

Reference

Definition

Namespace:: Android.OS

Assembly:: Mono.Android.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

StrictMode is a developer tool which detects things you might be doing by accident and brings them to your attention so you can fix them.

[Android.Runtime.Register("android/os/StrictMode", DoNotGenerateAcw=true)]
public sealed class StrictMode : Java.Lang.Object

[<Android.Runtime.Register("android/os/StrictMode", DoNotGenerateAcw=true)>]
type StrictMode = class
    inherit Object

Inheritance: Object

Object
StrictMode

Attributes: RegisterAttribute

Remarks

StrictMode is a developer tool which detects things you might be doing by accident and brings them to your attention so you can fix them.

StrictMode is most commonly used to catch accidental disk or network access on the application's main thread, where UI operations are received and animations take place. Keeping disk and network operations off the main thread makes for much smoother, more responsive applications. By keeping your application's main thread responsive, you also prevent ANR dialogs from being shown to users.

<p class="note">Note that even though an Android device's disk is often on flash memory, many devices run a filesystem on top of that memory with very limited concurrency. It's often the case that almost all disk accesses are fast, but may in individual cases be dramatically slower when certain I/O is happening in the background from other processes. If possible, it's best to assume that such things are not fast.

Example code to enable from early in your android.app.Application, android.app.Activity, or other application component's android.app.Application#onCreate method:

public void onCreate() {
                StrictMode.setThreadPolicy(new {@link ThreadPolicy.Builder StrictMode.ThreadPolicy.Builder}()
                        .detectDiskReads()
                        .detectDiskWrites()
                        .detectNetwork()   // or .detectAll() for all detectable problems
                        .penaltyLog()
                        .build());
                StrictMode.setVmPolicy(new {@link VmPolicy.Builder StrictMode.VmPolicy.Builder}()
                        .detectLeakedSqlLiteObjects()
                        .detectLeakedClosableObjects()
                        .penaltyLog()
                        .penaltyDeath()
                        .build());
                super.onCreate();
            }

You can decide what should happen when a violation is detected. For example, using ThreadPolicy.Builder#penaltyLog you can watch the output of adb logcat while you use your application to see the violations as they happen.

If you find violations that you feel are problematic, there are a variety of tools to help solve them: threads, android.os.Handler, android.os.AsyncTask, android.app.IntentService, etc. But don't feel compelled to fix everything that StrictMode finds. In particular, many cases of disk access are often necessary during the normal activity lifecycle. Use StrictMode to find things you did by accident. Network requests on the UI thread are almost always a problem, though.

<p class="note">StrictMode is not a security mechanism and is not guaranteed to find all disk or network accesses. While it does propagate its state across process boundaries when doing android.os.Binder calls, it's still ultimately a best effort mechanism. Notably, disk or network access from JNI calls won't necessarily trigger it.

Java documentation for android.os.StrictMode.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Properties

Class	Returns the runtime class of this `Object`. (Inherited from Object)
Handle	The handle to the underlying Android instance. (Inherited from Object)
JniIdentityHashCode	(Inherited from Object)
JniPeerMembers
PeerReference	(Inherited from Object)
ThresholdClass	This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. (Inherited from Object)
ThresholdType	This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. (Inherited from Object)

Methods

AllowThreadDiskReads()	A convenience wrapper that takes the current `ThreadPolicy` from `#getThreadPolicy`, modifies it to permit disk reads, and sets the new policy with `#setThreadPolicy`, returning the old policy so you can restore it at the end of a block.
AllowThreadDiskWrites()	A convenience wrapper that takes the current `ThreadPolicy` from `#getThreadPolicy`, modifies it to permit both disk reads & writes, and sets the new policy with `#setThreadPolicy`, returning the old policy so you can restore it at the end of a block.
Clone()	Creates and returns a copy of this object. (Inherited from Object)
Dispose()	(Inherited from Object)
Dispose(Boolean)	(Inherited from Object)
EnableDefaults()	Enable the recommended StrictMode defaults, with violations just being logged.
Equals(Object)	Indicates whether some other object is "equal to" this one. (Inherited from Object)
GetHashCode()	Returns a hash code value for the object. (Inherited from Object)
GetThreadPolicy()	Returns the current thread's policy.
GetVmPolicy()	Gets the current VM policy.
JavaFinalize()	Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. (Inherited from Object)
NoteSlowCall(String)	For code to note that it's slow.
Notify()	Wakes up a single thread that is waiting on this object's monitor. (Inherited from Object)
NotifyAll()	Wakes up all threads that are waiting on this object's monitor. (Inherited from Object)
SetHandle(IntPtr, JniHandleOwnership)	Sets the Handle property. (Inherited from Object)
SetThreadPolicy(StrictMode+ThreadPolicy)	Sets the policy for what actions on the current thread should be detected, as well as the penalty if such actions occur.
SetVmPolicy(StrictMode+VmPolicy)	Sets the policy for what actions in the VM process (on any thread) should be detected, as well as the penalty if such actions occur.
ToArray<T>()	(Inherited from Object)
ToString()	Returns a string representation of the object. (Inherited from Object)
UnregisterFromRuntime()	(Inherited from Object)
Wait()	Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>. (Inherited from Object)
Wait(Int64)	Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object)
Wait(Int64, Int32)	Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object)

Explicit Interface Implementations

IJavaPeerable.Disposed()	(Inherited from Object)
IJavaPeerable.DisposeUnlessReferenced()	(Inherited from Object)
IJavaPeerable.Finalized()	(Inherited from Object)
IJavaPeerable.JniManagedPeerState	(Inherited from Object)
IJavaPeerable.SetJniIdentityHashCode(Int32)	(Inherited from Object)
IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates)	(Inherited from Object)
IJavaPeerable.SetPeerReference(JniObjectReference)	(Inherited from Object)

Extension Methods

JavaCast<TResult>(IJavaObject)	Performs an Android runtime-checked type conversion.
JavaCast<TResult>(IJavaObject)
GetJniTypeName(IJavaPeerable)

Applies to