Android 作业

package com.example.myhomework2;
import androidx.appcompat.app.AppCompatActivity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity{
    double num1 = 0 , num2 = 0 , result = 0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public void click(View v){
        EditText et1 = findViewById(R.id.et1);
        EditText et2 = findViewById(R.id.et2);
        num1 = Double.parseDouble(et1.getText().toString());
        num2 = Double.parseDouble(et2.getText().toString());
        switch (v.getId())
        {
            case R.id.btn1:
                result = num1 + num2;
                break;
            case R.id.btn2:
                result = num1 - num2;
                break;
            case R.id.btn3:
                result = num1 * num2;
                break;
            case R.id.btn4:
                result = num1 / num2;
                break;
        }
    }
    public void click1(View v){
        TextView tv1 = findViewById(R.id.tv);
            /* @setProgress 设置初始进度
             * @setProgressStyle 设置样式（水平进度条）
     

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#789878">
    <EditText
        android:id="@+id/et1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <EditText
        android:id="@+id/et2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/et1" />
    <Button
        android:id="@+id/btn1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/et2"
        android:onClick="click"
        android:text="+" />
    <Button
        android:id="@+id/btn2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/et2"
        android:layout_toRightOf="@id/btn1"
        android:onClick="click"
        android:text="-" />
    <Button
        android:id="@+id/btn3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/et2"
        android:layout_toRightOf="@id/btn2"
        android:onClick="click"
        android:text="*" />
    <Button
        android:id="@+id/btn4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/et2"
        android:layout_toRightOf="@id/btn3"
        android:onClick="click"
        android:text="/" />
    <Button
        android:id="@+id/btn5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="计算"
        android:textColor="#025588"
        android:background="#895865"
        android:layout_below="@id/btn1"
        android:layout_marginLeft="20dp"
        android:onClick="click1"
        />
    <Button
        android:id="@+id/btn6"
        android:layout_width="wrap_content"

　　

        * @setMax 设置进度最大值              */             final int Max = 100;             final ProgressDialog progressDialog = new ProgressDialog(MainActivity.this);             progressDialog.setProgress(0);             progressDialog.setTitle("正在计算,请稍等...");             progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);             progressDialog.setMax(Max);             progressDialog.show();             /**              * 开个线程              */             new Thread(new Runnable() {                 @Override                 public void run() {                     int p = 0;                     while (p <= Max){                         try {                             Thread.sleep(10);