Android 界面设计 java.lang.NullPointerException 异常的解决方法

如果升级到最新的SDK 19后 ，有可能在界面设计那，出现这些异常。

java.lang.NullPointerException
	at com.android.layoutlib.bridge.impl.RenderSessionImpl.getDefaultProperties(RenderSessionImpl.java:1476)
	at com.android.layoutlib.bridge.BridgeRenderSession.getDefaultProperties(BridgeRenderSession.java:68)
	at com.android.ide.eclipse.adt.internal.editors.layout.gle2.ViewHierarchy.getDefaultProperties(ViewHierarchy.java:710)
	at com.android.ide.eclipse.adt.internal.editors.layout.properties.XmlProperty.getStringValue(XmlProperty.java:209)
	at com.android.ide.eclipse.adt.internal.editors.layout.properties.XmlProperty.getValue(XmlProperty.java:221)
	at com.android.ide.eclipse.adt.internal.editors.layout.properties.XmlPropertyEditor.getText(XmlPropertyEditor.java:116)
	at com.android.ide.eclipse.adt.internal.editors.layout.properties.XmlPropertyEditor.paint(XmlPropertyEditor.java:131)
	at org.eclipse.wb.internal.core.model.property.table.PropertyTable.drawProperty(PropertyTable.java:1309)
	at org.eclipse.wb.internal.core.model.property.table.PropertyTable.drawContent(PropertyTable.java:1151)
	at org.eclipse.wb.internal.core.model.property.table.PropertyTable.handlePaint(PropertyTable.java:1094)
	at org.eclipse.wb.internal.core.model.property.table.PropertyTable.access$200(PropertyTable.java:64)
	at org.eclipse.wb.internal.core.model.property.table.PropertyTable$3.handleEvent(PropertyTable.java:187)
	at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1077)
	at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1062)
	at org.eclipse.swt.widgets.Composite.WM_PRINTCLIENT(Composite.java:1639)
	at org.eclipse.swt.widgets.Control.windowProc(Control.java:4590)
	at org.eclipse.swt.widgets.Canvas.windowProc(Canvas.java:341)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:4976)
	at org.eclipse.swt.internal.win32.OS.CallWindowProcW(Native Method)
	at org.eclipse.swt.internal.win32.OS.CallWindowProc(OS.java:2440)
	at org.eclipse.swt.widgets.Button.callWindowProc(Button.java:343)
	at org.eclipse.swt.widgets.Control.windowProc(Control.java:4623)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:4989)
	at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)
	at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:2546)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3756)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1029)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:923)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:86)
	at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:588)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:543)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:353)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:601)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1438)


解决的办法 就是 把 版本 降回 18 ，就好了 ，估计是19的兼容性还有点问题。

选中你要修改的项目-〉 属性 -〉Android -> Project Build Target  改成 Android 4.3 apply  然后确定 就可以了。