Question

    TextView drawerName = (TextView) findViewById(R.id.drawerName);
    TextView drawerEmail = (TextView) findViewById(R.id.drawerEmail);
    CircleImageView drawerAvatar = (CircleImageView) findViewById(R.id.drawerAvatar);

    drawerName.setText(personName);
    drawerEmail.setText(personEmail);

致命的例外：主要过程：com.mje.dev.liqourstore，PID：1537 java.lang.RuntimeException：无法启动活动ComponentInfo {com.mje.dev.liqourstore / com.mje.dev.liqourstore.MainActivity}：java.lang.NullPointerException：尝试调用虚方法'void android.widget.TextView。 null对象引用上的setText（java.lang.CharSequence）' 在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:3149）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:3248）在android.app.ActivityThread.access $ 1000（ActivityThread.java:197）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1681）在android.os.Handler.dispatchMessage（Handler.java:102）在android.os.Looper.loop（Looper.java:145）在android.app.ActivityThread.main（ActivityThread.java:6872） at java.lang.reflect.Method.invoke（Native Method）在java.lang.reflect.Method.invoke（Method.java:372）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:1404）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:1199）引发者：java.lang.NullPointerException：尝试在空对象引用上调用虚方法'void android.widget.TextView.setText（java.lang.CharSequence）' 在com.mje.dev.liqourstore.MainActivity.onCreate（MainActivity.java:146）在android.app.Activity.performCreate（Activity.java:6550）在android.app.Instrumentation.callActivityOnCreate（Instrumentation.java:1120）在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:3102）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:3248）在android.app.ActivityThread.access $ 1000（ActivityThread.java:197）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1681）在android.os.Handler.dispatchMessage（Handler.java:102）在android.os.Looper.loop（Looper.java:145）在android.app.ActivityThread.main（ActivityThread.java:6872） at java.lang.reflect.Method.invoke（Native Method）在java.lang.reflect.Method.invoke（Method.java:372）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:1404）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:1199）

Answer 1

通过将contentView设置为View，您似乎未设置Activity setContentView。此外，还请检查setContentView布局是否还有您要提取的textview。

希望这会有所帮助。

Answer 2

    TextView drawerName = (TextView) navigationView.getHeaderView(0).findViewById(R.id.navDrawerName);
    TextView drawerEmail = (TextView) navigationView.getHeaderView(0).findViewById(R.id.navDrawerEmail);
    CircleImageView  drawerAvatar = (CircleImageView) navigationView.getHeaderView(0).findViewById(R.id.avatar);

继续收到此错误我不知道

2 个答案: