重新运行应用程序后，Butterknife 8.4.0找不到视图.它得到一个NullPointerException [英] Butterknife 8.4.0 does not find views after re-running the app. It gets a NullPointerException

问题描述

在Android Studio中重新运行应用程序后，Butterknife.bind(this)不再找到视图.到目前为止，我找到的唯一可靠的解决方案是使用Cleaning/Rebuilding Project并再次运行它.然后它将再次查找视图，直到下一次重新运行.到目前为止，这令人难以置信，而且至少需要两分钟才能进行重建.

After re-running the app in Android Studio Butterknife.bind(this) does not find the views anymore. The only reliable solution I found so far is by Cleaning/Rebuilding Project and run it again. Then it finds the views again until the next re-run. This is incredibly annoying so far and takes a minimum of two minutes for a rebuild.

我有以下build.gradle

android {

compileSdkVersion 24
buildToolsVersion "25.0.0"
defaultConfig {
    applicationId "xx"
    minSdkVersion 21
    targetSdkVersion 24
    versionCode x
    versionName "xxx"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    jackOptions {
        enabled true
    }
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

    }
}
packagingOptions {
    exclude 'META-INF/NOTICE' 
    exclude 'META-INF/LICENSE' 
}
compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}
}

dependencies {
    annotationProcessor 'com.jakewharton:butterknife-compiler:8.4.0'
    compile 'com.jakewharton:butterknife:8.4.0'
    androidTestCompile 'com.android.support.test.espresso:espresso-core:2.2.2'
    androidTestCompile 'com.android.support.test:runner:0.5'
    androidTestCompile 'com.android.support:support-annotations:24.2.1'
    compile 'com.android.support:appcompat-v7:24.2.1'
    compile 'com.android.support:design:24.2.1'
    compile 'com.android.support:support-v13:24.2.1'
    compile 'com.android.support:support-v4:24.2.1'
    compile 'com.android.support.test.espresso:espresso-idling-resource:2.2.2'

}

我也在使用构建工具com.android.tools.build:gradle:2.2.2

使用Butterknife.setDebug(true)，我得到以下信息:

With Butterknife.setDebug(true) I get the following:

D/ButterKnife: Looking up binding for xx.LoginFragment
D/ButterKnife: Not found. Trying superclass xx.BaseFragment
D/ButterKnife: Not found. Trying superclass android.app.Fragment
D/ButterKnife: MISS: Reached framework class. Abandoning search.

BaseFragment进行绑定，而LoginFragment对其进行扩展. 看起来像这样

The BaseFragment does the binding and LoginFragment extends it. It looks like this

BaseFragment import android.app.Fragment;

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v = inflater.inflate(getLayoutResourceId(), container, false);
        ButterKnife.setDebug(true);
        unbinder = ButterKnife.bind(this, v);
        initViews(v);
        return v;
    }

---

LoginFragment

@BindView(R.id.inputEmail)
    protected EditText inputEmail;

@Override
    protected void initViews(View v) {
        EditTextFocusListener focusListener = new EditTextFocusListener();
        inputEmail.setOnFocusChangeListener(focusListener);
    }

还有堆栈跟踪

  Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.EditText.setOnFocusChangeListener(android.view.View$OnFocusChangeListener)' on a null object reference
            at xx.LoginFragment.initViews(LoginFragment.java:51)
            at xx.BaseFragment.onCreateView(BaseFragment.java:53)

正如我之前所说，目前唯一可靠的解决方案是对整个项目进行完整的clean/rebuild.在使用jackCompiler之前，这种精确的结构可以正常工作，我无法再将其禁用.代码的主要部分取决于它.

As I said before the only solution which is reliable at the moment is to do a full clean/rebuild of the whole project. This exact structure worked fine before using the jackCompiler and I can not disable it anymore. Major part of the code depends on it.

推荐答案

这是一个临时解决方案，直到有人有更好的答案或在稳定的频道上发布它为止.

This is a temporary solution until someone has a better answer or it's released on the stable channel.

我转到Canary频道，并将Android Studio升级到2.3 Canary和com.android.tools.build:gradle:2.3.0-alpha1.其他所有内容均与开篇文章相同.

I changed to the canary channel and upgraded Android Studio to 2.3 Canary and com.android.tools.build:gradle:2.3.0-alpha1. Everything else stays the same as in the opening post.

我最终决定禁用jackCompiler并回滚到Java 1.7.现在很稳定.

I ultimately decided to disable the jackCompiler and roll back to Java 1.7. It's stable now.

jackOptions {
        enabled false
    } 

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