拥有以下日志：
java.lang.NumberFormatException: Color value 'OK' must start with #
at com.android.layoutlib.bridge.impl.ResourceHelper.getColor(ResourceHelper.java:87)
at com.android.layoutlib.bridge.impl.ResourceHelper.getDrawable(ResourceHelper.java:356)
at android.content.res.BridgeTypedArray.getDrawable(BridgeTypedArray.java:695)
at android.widget.LinearLayout.<init>(LinearLayout.java:238)
at android.widget.LinearLayout.<init>(LinearLayout.java:207)
at android.widget.LinearLayout.<init>(LinearLayout.java:203)
at android.support.design.widget.TextInputLayout.<init>(TextInputLayout.java:134)
at android.support.design.widget.TextInputLayout.<init>(TextInputLayout.java:129)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.jetbrains.android.uipreview.ViewLoader.createNewInstance(ViewLoader.java:465)
at org.jetbrains.android.uipreview.ViewLoader.loadClass(ViewLoader.java:172)
at org.jetbrains.android.uipreview.ViewLoader.loadView(ViewLoader.java:105)
at com.android.tools.idea.rendering.LayoutlibCallbackImpl.loadView(LayoutlibCallbackImpl.java:186)
at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:334)
at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:345)
at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:245)
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727)
at android.view.LayoutInflater.rInflate_Original(LayoutInflater.java:858)
at android.view.LayoutInflater_Delegate.rInflate(LayoutInflater_Delegate.java:70)
at android.view.LayoutInflater.rInflate(LayoutInflater.java:834)
at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821)
at android.view.LayoutInflater.inflate(LayoutInflater.java:518)
at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:324)
at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:429)
at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:389)
at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:548)
at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:533)
at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:966)
at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:533)
at com.android.tools.idea.rendering.RenderTask.lambda$inflate$53(RenderTask.java:659)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
和以下错误消息
failed to convert OK into a drawable
The graphics preview in the layout may not be accurate
Paint setShadowLayer is not supported
我启动了Android Studio，并在XML上提出了几个观点;除了他们没有出现在预览中！我只能假设这意味着android studio不会绘制XML上的任何内容;任何解释为什么？我能做些什么才能让android studio＆＃39;画出＆＃39;它？