1 <LinearLayout android:layout_width="fill_parent"
2 android:layout_height="fill_parent"
3 android:orientation="vertical"
4 xmlns:android="http://schemas.android.com/apk/res/android" >
5 <LinearLayout
6 android:layout_width="wrap_content"
7 android:layout_height="wrap_content"
8 android:layout_gravity="center">
9 <EditText
10 android:id="@+id/edit1"
11 android:layout_width="wrap_content"
12 android:layout_height="wrap_content"
13 android:hint="number1"
14 />
15 <TextView
16 android:id="@+id/txt"
17 android:layout_width="wrap_content"
18 android:layout_height="wrap_content"
19 android:text="+"
20 android:textSize="100px"
21 />
22 <EditText
23 android:id="@+id/edit2"
24 android:layout_width="wrap_content"
25 android:layout_height="wrap_content"
26 android:hint="number2"
27 />
28 <Button
29 android:id="@+id/bt"
30 android:layout_width="wrap_content"
31 android:layout_height="wrap_content"
32 android:text="="
33 android:textSize="50px"
34 />
35 <TextView
36 android:id="@+id/txt2"
37 android:layout_width="wrap_content"
38 android:layout_height="wrap_content"/>
39 </LinearLayout>
40 </LinearLayout>
1 package com.android.myapplication;
2
3 import androidx.appcompat.app.AppCompatActivity;
4
5 import android.annotation.SuppressLint;
6 import android.os.Bundle;
7 import android.view.View;
8 import android.widget.Button;
9 import android.widget.EditText;
10 import android.widget.TextView;
11
12 public class MainActivity extends AppCompatActivity {
13
14 public String txt;
15
16 @Override
17 protected void onCreate(Bundle savedInstanceState) {
18 super.onCreate(savedInstanceState);
19 setContentView(R.layout.activity_main);
20 final EditText editText1=findViewById(R.id.edit1);
21 final EditText editText2=findViewById(R.id.edit2);
22 final Button button=findViewById(R.id.bt);
23 final TextView textView=findViewById(R.id.txt2);
24 button.setOnClickListener(new View.OnClickListener() {
25 @Override
26 public void onClick(View v) {
27 int a,b;
28 a=Integer.parseInt(editText1.getText().toString());//String通过Interger转换成int
29 b=Integer.parseInt(editText2.getText().toString());
30 textView.setText(""+(a+b)); //这里很关键 int型需要这样操作：int+""
31 }
32 });
33 }
34 }
