package com.grassroots.booktracker.activity; import androidx.appcompat.app.AppCompatActivity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import com.grassroots.booktracker.R; public class MainActivity extends AppCompatActivity { private Button homeButton; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //初始化 homeButton= (Button) findViewById(R.id.button); //注册事件 homeButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { //创建Intent 对象 Intent intent=new Intent(MainActivity.this,LoginActivity.class); //启动Activity startActivity(intent); } }); } }