我的安卓手機到哪去了..一拖動那個十字架就報空指針null java.lang.NullPointerException at?com.android.tools.idea.uibuilder.surface.CanvasResizeInteraction.<init>(CanvasResizeInteraction.java:103) at?com.android.tools.idea.uibuilder.surface.InteractionManager$Listener.mousePressed(InteractionManager.java:446) at?java.awt.Component.processMouseEvent(Component.java:6530) at?javax.swing.JComponent.processMouseEvent(JComponent.java:3324) at?java.awt.Component.processEvent(Component.java:6298) at?java.awt.Container.processEvent(Container.java:2236) at?java.awt.Component.dispatchEventImpl(Component.java:4889) at?java.awt.Container.dispatchEventImpl(Container.java:2294) at?java.awt.Component.dispatchEvent(Component.java:4711) at?java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888) at?java.awt.LightweightDispatcher.processMouseEvent(Container.java:4522) at?java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466) at?java.awt.Container.dispatchEventImpl(Container.java:2280) at?java.awt.Window.dispatchEventImpl(Window.java:2746) at?java.awt.Component.dispatchEvent(Component.java:4711) at?java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758) at?java.awt.EventQueue.access$500(EventQueue.java:97) at?java.awt.EventQueue$3.run(EventQueue.java:709) at?java.awt.EventQueue$3.run(EventQueue.java:703) at?java.security.AccessController.doPrivileged(Native?Method) at?java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80) at?java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90) at?java.awt.EventQueue$4.run(EventQueue.java:731) at?java.awt.EventQueue$4.run(EventQueue.java:729) at?java.security.AccessController.doPrivileged(Native?Method) at?java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80) at?java.awt.EventQueue.dispatchEvent(EventQueue.java:728) at?com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:795) at?com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:627) at?com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:387) at?java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) at?java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at?java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) at?java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) at?java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) at?java.awt.EventDispatchThread.run(EventDispatchThread.java:82)Gradle?sync?failed:?Could?not?find?method?android()?for?arguments?[build_f2uiel5fv19yxv4mzot8n06jd$_run_closure3@6d1da161]?on?root?project?'HelloWorld'?of?type?org.gradle.api.Project. Consult?IDE?log?for?more?details?(Help?|?Show?Log)這是buider.gradle文件//?Top-level?build?file?where?you?can?add?configuration?options?common?to?all?sub-projects/modules. buildscript?{ ????repositories?{ ????????jcenter() ????} ????dependencies?{ ????????classpath?'com.android.tools.build:gradle:2.3.3' ????????//?NOTE:?Do?not?place?your?application?dependencies?here;?they?belong ????????//?in?the?individual?module?build.gradle?files ????} } allprojects?{ ????repositories?{ ????????jcenter() ????} } task?clean(type:?Delete)?{ ????delete?rootProject.buildDir } android?{ ????signingConfigs?{ ????} ????compileSdkVersion?23 ????buildToolsVersion?'26.0.0' ????dexOptions?{ ????????incremental?true ????} ????compileOptions?{ ????????sourceCompatibility?JavaVersion.VERSION_1_7 ????????targetCompatibility?JavaVersion.VERSION_1_7 ????} ????defaultConfig?{ ????????minSdkVersion?25 ????} ????productFlavors?{ ????} } dependencies?{ }