不工作带有空指针异常错误的Butterknife

Question

我正在尝试在我的Android项目中使用butternike。

这是我的简单代码。

分级依赖关系

compile 'com.jakewharton:butterknife:8.8.1'

布局

 <?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.rao.myapplication.LoginActivity">

    <EditText
        android:id="@+id/etUseName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <EditText
        android:id="@+id/etPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:layout_constraintTop_toBottomOf="@+id/etUseName"/>
    <Button
        android:id="@+id/btnLogin"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Login"
        android:onClick="loginClick"
        app:layout_constraintTop_toBottomOf="@+id/etPassword"/>

</android.support.constraint.ConstraintLayout>

 package com.example.rao.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.example.rao.myapplication.Presenter.LoginActivityPresenter;
import com.example.rao.myapplication.View.LoginActivityView;

import butterknife.BindView;
import butterknife.ButterKnife;

public class LoginActivity extends AppCompatActivity implements LoginActivityView {

    @BindView(R.id.etUseName)
    EditText userNameET;

    @BindView(R.id.etPassword)
    EditText passwordET;

    @BindView(R.id.btnLogin)
    Button loginBtn;

    private LoginActivityPresenter presenter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);

        ButterKnife.bind(this);
        passwordET.setText("abcd"); // Fails here as well
        presenter = new LoginActivityPresenter(this);
    }

    @Override
    public void navigateToListActivity() {

    }

    @Override
    public void loginFailed() {

    }

    public void loginClick(View view) {
        Toast.makeText(this, userNameET.getText().toString(), Toast.LENGTH_SHORT ).show(); // Fails here
        Toast.makeText(this, "test", Toast.LENGTH_SHORT ).show();
    }
}

Answer 1

在您的分级文件中添加以下行....

compile 'com.jakewharton:butterknife:8.8.1'
annotationProcessor 'com.jakewharton:butterknife-compiler:8.+'//add this line also

希望它能解决你的问题....