跳转与数据传递

 1 package com.example.myapplication;
 2 
 3 import androidx.appcompat.app.AppCompatActivity;
 4 
 5 import android.app.Activity;
 6 import android.content.Intent;
 7 import android.os.Bundle;
 8 import android.view.View;
 9 import android.widget.Button;
10 import android.widget.EditText;
11 import android.widget.TextView;
12 
13 import org.w3c.dom.Text;
14 
15 public class MainActivity extends Activity {
16 
17     @Override
18     protected void onCreate(Bundle savedInstanceState) {
19         super.onCreate(savedInstanceState);
20         setContentView(R.layout.login);
21     }
22 
23        public void login(View view){
24            EditText id = (EditText) findViewById(R.id.edit1);
25            String s = id.getText().toString();
26            Intent intent=new Intent();
27            intent.setClass(MainActivity.this, TestActivity.class);
28            intent.putExtra("id",s);
29            startActivity(intent);
30        }
31 
32 }

 1 package com.example.myapplication;
 2 
 3 import androidx.appcompat.app.AppCompatActivity;
 4 
 5 import android.content.Intent;
 6 import android.os.Bundle;
 7 import android.view.View;
 8 import android.widget.TextView;
 9 
10 public class TestActivity extends AppCompatActivity {
11 
12     @Override
13     protected void onCreate(Bundle savedInstanceState) {
14         super.onCreate(savedInstanceState);
15         setContentView(R.layout.activity_test);
16         TextView t = (TextView)findViewById(R.id.text);
17         Intent intent = this.getIntent();
18 
19         String id = intent.getStringExtra("id");
20         System.out.println(intent.getStringExtra("id"));
21         t.setText(id);
22     }
23 }

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     xmlns:app="http://schemas.android.com/apk/res-auto"
 4     xmlns:tools="http://schemas.android.com/tools"
 5     android:layout_width="match_parent"
 6     android:layout_height="match_parent"
 7     tools:context=".MainActivity">
 8 
 9     <TextView
10         android:layout_width="wrap_content"
11         android:layout_height="wrap_content"
12         android:text="Hello World!"
13         app:layout_constraintBottom_toBottomOf="parent"
14         app:layout_constraintLeft_toLeftOf="parent"
15         app:layout_constraintRight_toRightOf="parent"
16         app:layout_constraintTop_toTopOf="parent" />
17 
18 </androidx.constraintlayout.widget.ConstraintLayout>

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:orientation="vertical" android:layout_width="match_parent"
 4     android:layout_height="match_parent">
 5 <TextView
 6     android:layout_width="wrap_content"
 7     android:layout_height="wrap_content"
 8     android:text=""></TextView>
 9     <ImageView
10         android:id="@+id/photo"
11         android:layout_width="80dp"
12         android:layout_height="80dp"
13         android:src="@drawable/ic_launcher_background"
14         android:layout_centerHorizontal="true"
15         android:layout_marginTop="200dp"
16         android:layout_marginBottom="30dp"></ImageView>
17     <TextView
18         android:id="@+id/textView1"
19         android:layout_width="wrap_content"
20         android:layout_height="wrap_content"
21         android:layout_below="@id/photo"
22         android:maxLength="15"
23         android:layout_marginTop="13dp"
24         android:text="账号："/>
25     <EditText
26         android:id="@+id/edit1"
27         android:layout_width="match_parent"
28         android:layout_height="wrap_content"
29         android:layout_below="@id/photo"
30         android:layout_toRightOf="@id/textView1"
31         android:hint="请输入您的账号"></EditText>
32     <TextView
33         android:id="@+id/textView2"
34         android:layout_width="wrap_content"
35         android:layout_height="wrap_content"
36         android:layout_below="@id/textView1"
37         android:maxLength="20"
38         android:layout_marginTop="25dp"
39         android:text="密码：" />
40     <EditText
41         android:layout_width="match_parent"
42         android:layout_height="wrap_content"
43         android:layout_below="@id/textView1"
44         android:layout_toRightOf="@id/textView2"
45         android:layout_marginTop="10dp"
46         android:hint="请输入您的密码"/>
47     <Button
48         android:layout_width="wrap_content"
49         android:layout_height="wrap_content"
50         android:id="@+id/button"
51         android:text="登录"
52         android:textColor="#478595"
53         android:layout_below="@id/textView2"
54         android:layout_marginTop="20dp"
55         android:layout_marginLeft="120dp"
56         android:layout_centerHorizontal="true"
57         android:onClick="login">
58     </Button>
59 
60 </RelativeLayout>