Android studio实现加法软件

<LinearLayout 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=".jiafa_2_28Activity"
 android:orientation="vertical"
 android:gravity="center_horizontal">

 <TextView
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="30以内的加法"
  android:textSize="30sp"
  android:textColor="#000"/>
 <EditText
  android:id="@+id/et_1"
  android:layout_width="200dp"
  android:layout_height="wrap_content"
  android:textSize="25sp"
  android:layout_marginTop="10dp"
  android:enabled="false"
  android:textColor="#000"
  android:gravity="center"/>
 <EditText
  android:id="@+id/et_2"
  android:layout_width="200dp"
  android:layout_height="wrap_content"
  android:textSize="25sp"
  android:enabled="false"
  android:layout_marginTop="10dp"
  android:textColor="#000"
  android:gravity="center"/>
 <EditText
  android:id="@+id/et_3"
  android:layout_width="150dp"
  android:layout_height="wrap_content"
  android:textSize="25sp"
  android:textColor="#000"
  android:text=""
  android:gravity="center"/>
 <LinearLayout
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="horizontal"
  android:gravity="center_horizontal">
 <Button
  android:id="@+id/btn_1"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="运算结果"
  android:textSize="30sp"/>
  <Button
   android:id="@+id/btn_2"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:text="下一题"
   android:textSize="30sp"
   android:layout_marginLeft="30dp"/>
 </LinearLayout>
</LinearLayout>

public class jiafa_2_28Activity extends AppCompatActivity implements View.OnClickListener {

 private Button mBtn1,mBtn2;
 private EditText mEdit1,mEdit2,mEdit3;
 private Random mRandom;
 private int x,y;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_jiafa_2_28);
  mBtn1=findViewById(R.id.btn_1);
  mBtn2=findViewById(R.id.btn_2);
  mEdit1=findViewById(R.id.et_1);
  mEdit2=findViewById(R.id.et_2);
  mEdit3=findViewById(R.id.et_3);

  mBtn1.setOnClickListener(this);
  mBtn2.setOnClickListener(this);
  mRandom=new Random();
  myRandom();
  mEdit3.requestFocus();
 }

 private void myRandom(){
  x=mRandom.nextInt(30)+1;
  y=mRandom.nextInt(30)+1;
  mEdit1.setText(String.valueOf(x));
  mEdit2.setText(String.valueOf(y));
 }
 @Override
 public void onClick(View v) {
  String dite3=mEdit3.getText().toString();
  Pattern pattern=Pattern.compile("[0-9]*");
  Matcher matcher=pattern.matcher(dite3);
   switch (v.getId()) {
    case R.id.btn_1:
     if(matcher.matches()){
      if("".equals(dite3)){
        Toast.makeText(jiafa_2_28Activity.this,"请输入答案",Toast.LENGTH_SHORT).show();
        mEdit3.requestFocus();
      }else {
       int result = Integer.parseInt(dite3);
       if (result == x + y) {
        Toast.makeText(jiafa_2_28Activity.this, "恭喜你，回答正确", Toast.LENGTH_SHORT).show();
       } else {
        Toast.makeText(jiafa_2_28Activity.this, "回答错误", Toast.LENGTH_SHORT).show();
        mEdit3.setText("");
       }
      }
     }else{
      Toast.makeText(jiafa_2_28Activity.this,"输入的是非整数",Toast.LENGTH_SHORT).show();
      mEdit3.requestFocus();
     }
     break;
    case R.id.btn_2:
     mEdit3.setText("");
     myRandom();
     break;
   }
 }
}

private Button mBtn1,mBtn2;
private EditText mEdit1,mEdit2,mEdit3;
private Random mRandom;
private int x,y;
@Override
protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_jiafa_2_28);
 mBtn1=findViewById(R.id.btn_1);
 mBtn2=findViewById(R.id.btn_2);
 mEdit1=findViewById(R.id.et_1);
 mEdit2=findViewById(R.id.et_2);
 mEdit3=findViewById(R.id.et_3);
//通过View.OnClickListener接口来实现给按钮添加监听事件
 mBtn1.setOnClickListener(this);
 mBtn2.setOnClickListener(this);
 mRandom=new Random();
 myRandom();
 // 默认让焦点定位到mEdit3空间上
 mEdit3.requestFocus();
}

private void myRandom(){
 x=mRandom.nextInt(30)+1;
 y=mRandom.nextInt(30)+1;
 mEdit1.setText(String.valueOf(x));
 mEdit2.setText(String.valueOf(y));
}

//重写View.OnClickListener中的onClick方法
@Override
public void onClick(View v) {
//定义一个String属性的变量来接收mEdit3文本框中输入的元素
 String dite3=mEdit3.getText().toString();
 //通过正则表达式来判断输入的数值是否为数值类型
 Pattern pattern=Pattern.compile("[0-9]*");
 Matcher matcher=pattern.matcher(dite3);
 //通过switch方法判断点击的时哪个按钮
  switch (v.getId()) {
   case R.id.btn_1:
   //用equals方法来判断mEdit3中的内容是否为空，若为空则弹出Toast
   if(matcher.matches()){
    if("".equals(dite3)){
     Toast.makeText(jiafa_2_28Activity.this,"请输入答案",Toast.LENGTH_SHORT).show();
     mEdit3.requestFocus();
    }else {
    //将dite3获取到的mEdit3的值qiang'zhu强转为int型
     int result = Integer.parseInt(dite3);
     if (result == x + y) {
      Toast.makeText(jiafa_2_28Activity.this, "恭喜你，回答正确", Toast.LENGTH_SHORT).show();
     } else {
      Toast.makeText(jiafa_2_28Activity.this, "回答错误", Toast.LENGTH_SHORT).show();
      mEdit3.setText("");
     }
    }
   }else{
    Toast.makeText(jiafa_2_28Activity.this,"输入的是非整数",Toast.LENGTH_SHORT).show();
 mEdit3.requestFocus();
   }
    break;
   case R.id.btn_2:
   //若点击下一题则清空mEdit3中的内容，并再调用myRandom获取随机数
    mEdit3.setText("");
    myRandom();
    break;
  }
}