java.lang.ClassCastException:android.widget.LinearLayout无法强制转换为android.support.v7.widget.Toolbar [英]java.lang.ClassCastException: android.widget.LinearLayout cannot be cast to android.support.v7.widget.Toolbar
java.lang.ClassCastException:android.support.design.widget.AppBarLayout无法转换为android.support.v7.widget.Toolbar [英]java.lang.ClassCastException: android.support.design.widget.AppBarLayout cannot be cast to android.support.v7.widget.Toolbar
在空对象引用上使 android.support.v7.widget.Toolbar.setTitle(java.lang.CharSequence)'无效 [英]Void android.support.v7.widget.Toolbar.setTitle(java.lang.CharSequence)' on a null object reference
android.support.v7.widget.toolbar 在使用 android studio 的 java 文件中找不到? [英]android.support.v7.widget.toolbar is not found in java file using android studio?
如何修复 Java 中的“找不到以下类:-android.support.v7.widget.Toolbar”错误 [英]How to fix 'The following classes could not be found: - android.support.v7.widget.Toolbar' error in Java