Android学习笔记|Android开发一个简单的交互式App Android学习笔记|android

1、功能分析

2、开发视图布局

activity_main.xml

android:id="@+id/feature" android:layout_width="match_parent" android:layout_height="wrap_content" android:entries="@array/feature" android:minHeight="32dp" />
strings.xml

name="app_name">ProgramAdviser name="find_language">Find Language name="language">Select and Click name="feature"> fast easy new OO
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3、按钮事件响应

MainActivity类

public class MainActivity extends AppCompatActivity {@Override protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); }public void onClickButton(View button){//获得Spinner引用 Spinner spinner = findViewById(R.id.feature); //获得Spinner选项 String feature = spinner.getSelectedItem().toString(); //获得TextView引用 TextView textView = findViewById(R.id.language); //设置TextView文字 textView.setText(feature); } }

4、开发模型层

ProgramExpert类，和MainActivity同级

public class ProgramExpert {public String getLangunage(String feature){String result; switch (feature){case "fast": result = "C/C++"; break; case "easy": result = "Python"; break; case "new": result = "Kotlin"; break; case "OO" : result = "Java"; break; default: result = "You got me"; } return result; } }
修改MainActivity类

package szst.it.ping.programadviser; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Spinner; import android.widget.TextView; public class MainActivity extends AppCompatActivity {//private封装实例变量，final保证expert被初始化 //final的实例变量赋值后无法改变，声明后必须立即初始化 private final ProgramExpert expert = new ProgramExpert(); @Override protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); }public void onClickButton(View button){//获得Spinner引用 Spinner spinner = findViewById(R.id.feature); //获得Spinner选项 String feature = spinner.getSelectedItem().toString(); //查询模型层 String langunage = expert.getLangunage(feature); //获得TextView引用 TextView textView = findViewById(R.id.language); //设置TextView文字 //textView.setText(feature); textView.setText(langunage); } }

5、测试结果 【Android学习笔记|Android开发一个简单的交互式App】