diff --git a/.gitignore b/.gitignore
index 09b993d06..5f0e23e18 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,5 @@
 /build
 /captures
 .externalNativeBuild
+/release
+/tmp
\ No newline at end of file
diff --git a/app/src/main/java/io/legado/app/utils/ContextExtensions.kt b/app/src/main/java/io/legado/app/utils/ContextExtensions.kt
new file mode 100644
index 000000000..a94267fda
--- /dev/null
+++ b/app/src/main/java/io/legado/app/utils/ContextExtensions.kt
@@ -0,0 +1,42 @@
+package io.legado.app.utils
+
+import android.content.Context
+import androidx.core.content.edit
+import org.jetbrains.anko.connectivityManager
+import org.jetbrains.anko.defaultSharedPreferences
+
+fun Context.isOnline() = connectivityManager.activeNetworkInfo?.isConnected == true
+
+fun Context.getPrefBoolean(key: String, defValue: Boolean) =
+    defaultSharedPreferences.getBoolean(key, defValue)
+
+fun Context.putPrefBoolean(key: String, value: Boolean) =
+    defaultSharedPreferences.edit { putBoolean(key, value) }
+
+
+fun Context.getPrefInt(key: String, defValue: Int) =
+    defaultSharedPreferences.getInt(key, defValue)
+
+fun Context.putPrefInt(key: String, value: Int) =
+    defaultSharedPreferences.edit { putInt(key, value) }
+
+fun Context.getPrefLong(key: String, defValue: Long) =
+    defaultSharedPreferences.getLong(key, defValue)
+
+fun Context.putPrefLong(key: String, value: Long) =
+    defaultSharedPreferences.edit { putLong(key, value) }
+
+fun Context.getPrefString(key: String, defValue: String) =
+    defaultSharedPreferences.getString(key, defValue)
+
+fun Context.putPrefString(key: String, value: String) =
+    defaultSharedPreferences.edit { putString(key, value) }
+
+fun Context.getPrefStringSet(key: String, defValue: MutableSet<String>) =
+    defaultSharedPreferences.getStringSet(key, defValue)
+
+fun Context.putPrefStringSet(key: String, value: MutableSet<String>) =
+    defaultSharedPreferences.edit { putStringSet(key, value) }
+
+fun Context.removePref(key: String) =
+    defaultSharedPreferences.edit { remove(key) }