第一次提交代码

MainActivity.java

@@ -0,0 +1,45 @@
+package com.example.myapplication;
+
+import android.content.ComponentName;
+import android.content.Intent;
+import android.os.Bundle;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.Toast;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+public class MainActivity extends AppCompatActivity {
+    Button loginB, newUser;
+    EditText usernameET, passwordET;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_main);
+        initView();
+        loginB.setOnClickListener(v -> {
+            Toast.makeText(MainActivity.this, "登录成功", Toast.LENGTH_LONG).show();
+            Intent intent = new Intent();
+            ComponentName componentName = new ComponentName(MainActivity.this, InfoActivity.class);
+            intent.setComponent(componentName);
+            startActivity(intent);
+        });
+        newUser.setOnClickListener(v -> {
+            Intent intent = new Intent();
+            ComponentName componentName = new ComponentName(MainActivity.this, MainActivity2.class);
+            intent.setComponent(componentName);
+            startActivity(intent);
+        });
+    }
+
+    /**
+     * 初始化视图绑定
+     */
+    void initView() {
+        loginB = findViewById(R.id.login);
+        usernameET = findViewById(R.id.username);
+        passwordET = findViewById(R.id.password);
+        newUser = findViewById(R.id.newUser);
+    }
+}