第三次作业

<?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">    <LinearLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_marginTop="60dp"        android:orientation="vertical"        android:padding="30dp">        <TextView            android:id="@+id/text1"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_marginLeft="100dp"            android:drawableLeft="@drawable/bg"            android:text="QQ"            android:textSize="50sp" />        <EditText            android:id="@+id/edt1"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:layout_marginTop="35dp"            android:textSize="30sp"            android:hint="QQ号/邮箱/手机号" />        <EditText            android:id="@+id/edt2"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:textSize="30sp"            android:hint="密码"            android:password="true"/>        <RelativeLayout            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:layout_marginTop="10dp">        </RelativeLayout>        <Button            android:id="@+id/btn1"            android:layout_width="match_parent"            android:layout_marginTop="10dp"            android:layout_height="60dp"            android:text="登录"            android:textSize="30sp"            android:background="#55EEAA"            android:onClick="click"            />    </LinearLayout></RelativeLayout>

package com.example.qq;        import androidx.appcompat.app.AppCompatActivity;        import android.os.Bundle;        import android.view.View.OnClickListener;        import android.view.View;        import android.widget.EditText;        import android.widget.LinearLayout;        import android.widget.TextView;        import android.widget.Button;        import android.widget.Toast;public class MainActivity extends AppCompatActivity {    private Button btn1;    EditText account = null;    EditText code = null;    EditText t1;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        t1=(EditText) findViewById(R.id.edt1);        account = (EditText) findViewById(R.id.edt1);        code = (EditText) findViewById(R.id.edt2);        btn1=(Button) findViewById(R.id.btn1);        btn1.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View view) {                String username = ((EditText) findViewById(R.id.edt1)).getText().toString();                String pwd = ((EditText) findViewById(R.id.edt2)).getText().toString();                if (username.equals("123456") && pwd.equals("abc123")) {                    Toast.makeText(MainActivity.this,"登陆成功",Toast.LENGTH_SHORT).show();                } else {                    t1.setText("账号或密码错误请重新输入");                    Toast.makeText(MainActivity.this,"登陆失败",Toast.LENGTH_SHORT).show();                }            }        });    }}

来源：https://www.cnblogs.com/xiaohusha/p/11493116.html