package com.example.test3;
 
import android.app.AliasActivity;
import android.app.ProgressDialog;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
  
  
  
public class MainActivity extends AliasActivity{
  
    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 = (EditText) findViewById(R.id.et1);
        EditText et2 = (EditText) 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 = (TextView) findViewById(R.id.tv);
  
            /* @setProgress 设置初始进度
             * @setProgressStyle 设置样式（水平进度条）
             * @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);
                            p++;
                            progressDialog.setProgress(p);
                        }catch (Exception e){
                            e.printStackTrace();
                        }
                    }
                    progressDialog.cancel();//达到最大就消失
                }
  
            }).start();
  
        tv1.setText("计算结果:" + result + "");
  
    }
  
    public void click2(View v){
        EditText et1 = (EditText) findViewById(R.id.et1);
        EditText et2 = (EditText) findViewById(R.id.et2);
        TextView tv = (TextView) findViewById(R.id.tv);
        et1.setText("");
        et2.setText("");
        tv.setText("");
    }
  
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#786678" >
 
    <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:layout_below="@id/btn1"
        android:layout_marginLeft="20dp"
        android:background="#895865"
        android:onClick="click1"
        android:text="计算"
        android:textColor="#024488" />
 
    <Button
        android:id="@+id/btn6"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/btn4"
        android:layout_marginLeft="135dp"
        android:layout_toRightOf="@id/btn5"
        android:background="#895865"
        android:onClick="click2"
        android:text="清空"
        android:textColor="#024488" />
 
    <TextView
        android:id="@+id/tv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/btn5"
        android:layout_marginLeft="20dp"
        android:layout_marginTop="20dp"
        android:text="计算结果:" />
 
</RelativeLayout>