Question

背景

我遇到了这个错误：

java.lang.NullPointerException
    at android.content.res.Resources_Delegate.getValue(Resources_Delegate.java:788)
    at android.content.res.Resources.getValue(Resources.java:1286)
    at android.support.v4.content.res.ResourcesCompat.loadFont(ResourcesCompat.java:212)
    at android.support.v4.content.res.ResourcesCompat.getFont(ResourcesCompat.java:206)
    at android.support.v7.widget.TintTypedArray.getFont(TintTypedArray.java:119)
    at android.support.v7.widget.AppCompatTextHelper.updateTypefaceAndStyle(AppCompatTextHelper.java:208)
    at android.support.v7.widget.AppCompatTextHelper.loadFromAttributes(AppCompatTextHelper.java:152)
    at android.support.v7.widget.AppCompatTextHelperV17.loadFromAttributes(AppCompatTextHelperV17.java:38)
    at android.support.v7.widget.AppCompatTextView.<init>(AppCompatTextView.java:81)
    at android.support.v7.widget.AppCompatTextView.<init>(AppCompatTextView.java:71)
    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:475)
    at org.jetbrains.android.uipreview.ViewLoader.loadClass(ViewLoader.java:250)
    at org.jetbrains.android.uipreview.ViewLoader.loadClass(ViewLoader.java:213)
    at com.android.tools.idea.rendering.LayoutlibCallbackImpl.loadClass(LayoutlibCallbackImpl.java:193)
    at android.view.BridgeInflater.loadCustomView(BridgeInflater.java:333)
    at android.view.BridgeInflater.onCreateView(BridgeInflater.java:152)
    at android.view.LayoutInflater.onCreateView(LayoutInflater.java:717)
    at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:785)
    at android.view.BridgeInflater.createViewFromTag(BridgeInflater.java:222)
    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.inflate(LayoutInflater.java:492)
    at com.android.layoutlib.bridge.bars.CustomBar.<init>(CustomBar.java:95)
    at com.android.layoutlib.bridge.bars.StatusBar.<init>(StatusBar.java:67)
    at com.android.layoutlib.bridge.impl.Layout.createStatusBar(Layout.java:224)
    at com.android.layoutlib.bridge.impl.Layout.<init>(Layout.java:146)
    at com.android.layoutlib.bridge.impl.RenderSessionImpl.inflate(RenderSessionImpl.java:301)
    at com.android.layoutlib.bridge.Bridge.createSession(Bridge.java:429)
    at com.android.ide.common.rendering.LayoutLibrary.createSession(LayoutLibrary.java:368)
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:567)
    at com.android.tools.idea.rendering.RenderTask$2.compute(RenderTask.java:549)
    at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:863)
    at com.android.tools.idea.rendering.RenderTask.createRenderSession(RenderTask.java:549)
    at com.android.tools.idea.rendering.RenderTask.lambda$inflate$1(RenderTask.java:680)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

适用于应用中的每个布局（.xml）。

我试过这个solution。上面的xml错误消失但视图无法正确呈现。几天前，我的应用程序正常工作，没有添加Base。我正在使用版本控制，所以我确信Base不是问题。我正在测试Universal Image Loader库。仅在测试后，我恢复了所有更改。之后，每个xml都会弹出此错误。（每个，事情都很好，直到最后一次提交）。我不知道什么坏了？我也尝试了其他解决方案（无效的缓存和内容。但都是徒劳的。）

Gradle build（app）：

 compile 'com.android.support:support-v4:26.+'
    compile 'com.android.support:appcompat-v7:26.+'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    compile 'com.android.support:design:26.+'
    compile 'com.android.support:recyclerview-v7:26.+'
    compile 'com.android.support:cardview-v7:26.+'
    compile 'com.android.support:palette-v7:26.+'
    compile 'com.squareup.picasso:picasso:2.5.2'
    compile 'com.squareup.okhttp3:okhttp:3.8.1'
    compile 'uk.co.chrisjenx:calligraphy:2.2.0'
    compile 'com.github.bluejamesbond:textjustify-android:2.1.6'
    testCompile 'junit:junit:4.12'
    compile 'com.google.android.gms:play-services-ads:11.0.0'

Answer 1

你试过重建/清理项目吗？有时这种类型的错误是通过那个或无效的缓存和重启来解决的？尝试一下，可能有所帮助。

Answer 2

对我有用的解决方案：

打开 - ＆＃34; styles.xml＆＃34;

更改 - 父=＆＃34; Base.Theme.AppCompact。（您首选的风格）＆＃34;

无法实例化一个或多个calsses（android.support.v7.widget.AppCompatTextView）

背景

2 个答案: