4.安卓练习

import androidx.appcompat.app.AppCompatActivity;

 

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

 

import org.w3c.dom.Text;

 

public class MainActivity extends Activity {

 

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.login);

    }

 

       public void login(View view){

           EditText id = (EditText) findViewById(R.id.edit1);

           String s = id.getText().toString();

           Intent intent=new Intent();

           intent.setClass(MainActivity.this, TestActivity.class);

           intent.putExtra("id",s);

           startActivity(intent);

       }

 

}

　　

?

import androidx.appcompat.app.AppCompatActivity;   import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.TextView;   public class TestActivity extends AppCompatActivity {       @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_test);         TextView t = (TextView)findViewById(R.id.text);         Intent intent = this.getIntent();           String id = intent.getStringExtra("id");         System.out.println(intent.getStringExtra("id"));         t.setText(id);     } }

　　

?

<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context=".MainActivity">       <TextView         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="Hello World!"         app:layout_constraintBottom_toBottomOf="parent"         app:layout_constraintLeft_toLeftOf="parent"         app:layout_constraintRight_toRightOf="parent"         app:layout_constraintTop_toTopOf="parent" />   </androidx.constraintlayout.widget.ConstraintLayout>

　　

?

<?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context=".MainActivity">       <TextView         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="Hello World!"         app:layout_constraintBottom_toBottomOf="parent"         app:layout_constraintLeft_toLeftOf="parent"         app:layout_constraintRight_toRightOf="parent"         app:layout_constraintTop_toTopOf="parent" />   </androidx.constraintlayout.widget.ConstraintLayout>

　　

?

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:orientation="vertical" android:layout_width="match_parent"     android:layout_height="match_parent"> <TextView     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:text=""></TextView>     <ImageView         android:id="@+id/photo"         android:layout_width="80dp"         android:layout_height="80dp"         android:src="@drawable/ic_launcher_background"         android:layout_centerHorizontal="true"         android:layout_marginTop="200dp"         android:layout_marginBottom="30dp"></ImageView>     <TextView         android:id="@+id/textView1"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_below="@id/photo"         android:maxLength="15"         android:layout_marginTop="13dp"         android:text="账号："/>     <EditText         android:id="@+id/edit1"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:layout_below="@id/photo"         android:layout_toRightOf="@id/textView1"         android:hint="请输入您的账号"></EditText>     <TextView         android:id="@+id/textView2"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_below="@id/textView1"         android:maxLength="20"         android:layout_marginTop="25dp"         android:text="密码：" />     <EditText         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:layout_below="@id/textView1"         android:layout_toRightOf="@id/textView2"         android:layout_marginTop="10dp"         android:hint="请输入您的密码"/>     <Button         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:id="@+id/button"         android:text="登录"         android:textColor="#478595"         android:layout_below="@id/textView2"         android:layout_marginTop="20dp"         android:layout_marginLeft="120dp"         android:layout_centerHorizontal="true"         android:onClick="login">     </Button>   </RelativeLayout>