Android按钮及按钮处理事件

MainActivity.java代码

package com.example.hello;

import androidx.appcompat.app.AppCompatActivity;

import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    private TextView txt;
    private TextView zt;
    private Button button;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        txt = (TextView)findViewById(R.id.pwd1);
        zt = (TextView)findViewById(R.id.zt1);
        button = (Button)findViewById(R.id.button1);
        button.setOnClickListener(new mClick());
    }

    class mClick implements View.OnClickListener {
        public void onClick(View view){
            String pwds;
            pwds = txt.getText().toString();
            if(pwds.equals("123"))
                zt.setText("登录成功");
            else
                zt.setText("登录失败");
        }
    }
}

activity_main.xml代码

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_height="match_parent"
    android:layout_width="match_parent"
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android">
<!--    <TextView
        android:id="@+id/txt1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello"
        android:textColor="#0ff"
        android:gravity="center"
        />-->
    <EditText
        android:id="@+id/acnt1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入账户" />
    <EditText
        android:id="@+id/pwd1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="请输入密码"
        android:inputType="textPassword"/>
    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="登录"
        android:layout_gravity="center" />
    <TextView
        android:id="@+id/zt1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="登录状态:无"/>
</LinearLayout>

程序样式