java.lang.RuntimeException：使用不同版本的库和 sdk 时无法启动活动 ComponentInfo

问：

问题出在下面的日志上。它实际上运行良好，但是当我使用相同的代码并在日志以下出现这些错误时运行它。当我尝试打开它时，我的应用程序总是强制关闭，因此我根本无法打开我的应用程序。我需要升级版本，因为 android studio 上的自适应图标仅在或更高版本上可用buildToolsVersion "25.0.3"buildToolsVersion "29.0.2"buildToolsVersion "26.0.0"

我在尝试在空对象引用上调用虚拟方法“void android.widget.Button.setOnClickListener（android.view.View$OnClickListener）”时发现了相同的错误，但仍然没有正确答案，并且由于我使用了butterknife库，因此错误可能是因为库的版本，或者我的代码有问题。

错误日志：

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.aat.simenwa, PID: 23292
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.aat.simenwa/com.aat.simenwa.activity.LoginActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2976)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3113)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:113)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:71)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1858)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:201)
        at android.app.ActivityThread.main(ActivityThread.java:6820)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:922)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at com.aat.simenwa.activity.LoginActivity.onCreate(LoginActivity.java:55)
        at android.app.Activity.performCreate(Activity.java:7224)
        at android.app.Activity.performCreate(Activity.java:7213)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1272)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2956)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3113) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:113) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:71) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1858) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:201) 
        at android.app.ActivityThread.main(ActivityThread.java:6820) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:922) 
I/com.aat.simenw: ProcessProfilingInfo new_methods=0 is saved saved_to_disk=0 resolve_classes_delay=8000
Process 23292 terminated.

LoginActivity 类：

import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.aat.simenwa.R;
import com.aat.simenwa.util.SharedPrefManager;
import com.aat.simenwa.util.api.BaseApiService;
import com.aat.simenwa.util.api.UtilsApi;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;

import butterknife.BindView;
import butterknife.ButterKnife;
import okhttp3.ResponseBody;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;

public class LoginActivity extends AppCompatActivity {

    @BindView(R.id.etEmail) EditText etEmail;
    @BindView(R.id.etPassword) EditText etPassword;
    @BindView(R.id.btnLogin) Button btnLogin;
    @BindView(R.id.btnRegister) Button btnRegister;
    ProgressDialog loading;

    Context mContext;
    BaseApiService mApiService;

    SharedPrefManager sharedPrefManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        getSupportActionBar().hide();

        ButterKnife.bind(this);
        mContext = this;
        mApiService = UtilsApi.getAPIService(); // meng-init yang ada di package apihelper
        sharedPrefManager = new SharedPrefManager(this);

        btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                loading = ProgressDialog.show(mContext, null, "Harap Tunggu...", true, false);
                requestLogin();
            }
        });

        btnRegister.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startActivity(new Intent(mContext, RegisterActivity.class));
            }
        });

        // Code berikut berfungsi untuk mengecek session, Jika session true ( sudah login )
        // maka langsung memulai MainActivity.
        if (sharedPrefManager.getSPSudahLogin()){
            startActivity(new Intent(LoginActivity.this, MainActivity.class)
                    .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK));
            finish();
        }
    }

    private void requestLogin(){
        mApiService.loginRequest(etEmail.getText().toString(), etPassword.getText().toString())
                .enqueue(new Callback<ResponseBody>() {
                    @Override
                    public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
                        if (response.isSuccessful()){
                            loading.dismiss();
                            try {
                                JSONObject jsonRESULTS = new JSONObject(response.body().string());
                                if (jsonRESULTS.getString("error").equals("false")){
                                    // Jika login berhasil maka data nama yang ada di response API
                                    // akan diparsing ke activity selanjutnya.
                                    Toast.makeText(mContext, "BERHASIL LOGIN", Toast.LENGTH_SHORT).show();
                                    String nama = jsonRESULTS.getJSONObject("user").getString("nama");
                                    sharedPrefManager.saveSPString(SharedPrefManager.SP_NAMA, nama);
                                    // Shared Pref ini berfungsi untuk menjadi trigger session login
                                    sharedPrefManager.saveSPBoolean(SharedPrefManager.SP_SUDAH_LOGIN, true);
                                    startActivity(new Intent(mContext, MainActivity.class)
                                            .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK));
                                    finish();
                                } else {
                                    // Jika login gagal
                                    String error_message = jsonRESULTS.getString("error_msg");
                                    Toast.makeText(mContext, error_message, Toast.LENGTH_SHORT).show();
                                }
                            } catch (JSONException e) {
                                e.printStackTrace();
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        } else {
                            loading.dismiss();
                        }
                    }

                    @Override
                    public void onFailure(Call<ResponseBody> call, Throwable t) {
                        Log.e("debug", "onFailure: ERROR > " + t.toString());
                        loading.dismiss();
                    }
                });
    }
}

activity_login布局：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/background_gradient"
    tools:context="com.aat.simenwa.activity.LoginActivity">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:padding="16dp"
        android:orientation="vertical">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:fontFamily="sans-serif-medium"
            android:text="SIMENWA"
            android:textColor="#fff"
            android:textSize="48sp"
            android:textStyle="normal|bold|italic" />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:fontFamily="sans-serif"
            android:text="LOGIN"
            android:textColor="#fff"
            android:textSize="24sp" />

        <EditText
            android:id="@+id/etEmail"
            android:layout_marginTop="8dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="Email"
            android:textColorHint="#80FFFFFF"
            android:padding="8dp"
            android:inputType="textEmailAddress"
            android:background="@drawable/bg_rectangle_edittext"
            android:textColor="#80FFFFFF"/>

        <EditText
            android:id="@+id/etPassword"
            android:layout_marginTop="8dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="Password"
            android:textColorHint="#80FFFFFF"
            android:inputType="textPassword"
            android:padding="8dp"
            android:background="@drawable/bg_rectangle_edittext"
            android:textColor="#80FFFFFF"/>

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:fontFamily="sans-serif"
            android:text="Sekolah Tinggi Ilmu Statistik"
            android:textColor="#fff"
            android:textSize="18sp"/>

        <Button
            android:id="@+id/btnLogin"
            android:layout_marginTop="16dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColor="#FFF"
            android:text="LOG IN"
            android:background="@drawable/bg_rectangle_button"/>

        <TextView
            android:layout_marginTop="8dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="#FFF"
            android:fontFamily="cursive"
            android:text="OR"
            android:layout_gravity="center"/>

        <Button
            android:id="@+id/btnRegister"
            android:layout_marginTop="8dp"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textColor="#FFF"
            android:text="REGISTER"
            android:background="@drawable/bg_rectangle_button"/>
    </LinearLayout>
</RelativeLayout>