这是我Android学习的第一天，第一堂课的作业是写两个button，分别实现点击显示hello world 和图片消息。
实现代码如下：
activity_main.xml:
1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout 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="com.example.zhangqiongwen.homework1.MainActivity" 8 tools:layout_editor_absoluteY="81dp"> 9 10 <include layout="@layout/button"> 11 12 </include> 13 </RelativeLayout>
button.xml:
1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout 3 xmlns:android="http://schemas.android.com/apk/res/android" 4 android:layout_width="match_parent" 5 android:layout_height="match_parent"> 6 7 8 <RelativeLayout 9 android:id="@+id/button_layout" 10 android:layout_width="380dp" 11 android:layout_height="wrap_content" 12 android:layout_alignParentStart="true" 13 android:layout_alignParentTop="true"> 14 15 <Button 16 android:id="@+id/button1" 17 android:layout_width="120dp" 18 android:layout_height="40dp" 19 android:layout_alignParentTop="true" 20 android:layout_alignParentLeft="true" 21 android:onClick="click" 22 android:text="button1" /> 23 24 <Button 25 android:id="@+id/button2" 26 android:layout_width="120dp" 27 android:layout_height="40dp" 28 android:onClick="click" 29 android:layout_alignParentTop="true" 30 android:layout_alignParentRight="true" 31 android:text="button2" /> 32 </RelativeLayout> 33 34 35 </RelativeLayout>
page1.xml:
1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout 3 xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" 4 android:layout_height="match_parent"> 5 6 <include 7 layout="@layout/button"> 8 </include> 9 10 <TextView 11 android:layout_width="wrap_content" 12 android:layout_height="wrap_content" 13 android:layout_centerVertical="true" 14 android:layout_centerHorizontal="true" 15 android:text="Hello world!!" 16 android:textColor="#FF79BC" 17 /> 18 19 </RelativeLayout>
page2.xml:
1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout 3 xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" 4 android:layout_height="match_parent"> 5 6 <include layout="@layout/button"/> 7 8 <LinearLayout 9 android:layout_width="match_parent" 10 android:layout_height="300dp" 11 android:layout_marginTop="40dp" 12 > 13 14 <ImageView 15 android:id="@+id/picture1" 16 android:layout_width="match_parent" 17 android:layout_height="match_parent" 18 android:layout_alignParentStart="true" 19 android:layout_alignParentTop="true" 20 android:src="@drawable/pictur1" /> 21 22 </LinearLayout> 23 24 </RelativeLayout>
activity.java:
1 package com.example.zhangqiongwen.homework1;
2
3 import android.app.Activity;
4 import android.content.Intent;
5 import android.os.Bundle;
6 import android.support.annotation.Nullable;
7 import android.view.View;
8 import android.widget.Button;
9
10
11 public class MainActivity extends Activity{
12 @Override
13 protected void onCreate(@Nullable Bundle savedInstanceState) {
14 super.onCreate(savedInstanceState);
15 this.setContentView(R.layout.activity_main);
16
17 Button btn1 = (Button)findViewById(R.id.button1);
18 Button btn2 = (Button)findViewById(R.id.button2);
19
20
21 btn1.setOnClickListener(new View.OnClickListener() {
22 @Override
23 public void onClick(View view) {
24 Intent i = new Intent(MainActivity.this , page1.class);
25 startActivity(i);
26 }
27 });
28
29 btn2.setOnClickListener(new View.OnClickListener() {
30 @Override
31 public void onClick(View view) {
32 Intent b = new Intent(MainActivity.this , page2.class);
33 startActivity(b);
34 }
35 });
36
37 }
38 }
page1.java
1 import android.app.Activity;
2 import android.content.Intent;
3 import android.os.Bundle;
4 import android.support.annotation.Nullable;
5 import android.view.ContextMenu;
6 import android.view.View;
7 import android.widget.Button;
8 import android.widget.RelativeLayout;
9
10 /**
11 * Created by zhang.qiongwen on 2019/8/10.
12 */
13
14 public class page1 extends Activity {
15
16 @Override
17 protected void onCreate(@Nullable Bundle savedInstanceState) {
18 super.onCreate(savedInstanceState);
19
20 setContentView(R.layout.page1);
21
22
23 Button btn1 = (Button)findViewById(R.id.button1);
24 Button btn2 = (Button)findViewById(R.id.button2);
25
26 btn1.setOnClickListener(new View.OnClickListener() {
27 @Override
28 public void onClick(View view) {
29 Intent i = new Intent(page1.this , page1.class);
30 startActivity(i);
31 }
32 });
33
34 btn2.setOnClickListener(new View.OnClickListener() {
35 @Override
36 public void onClick(View view) {
37 Intent b = new Intent(page1.this , page2.class);
38 startActivity(b);
39 }
40 });
41
42
43 }
44 }
page2.java
1 package com.example.zhangqiongwen.homework1;
2
3 import android.app.Activity;
4 import android.content.Intent;
5 import android.os.Bundle;
6 import android.support.annotation.Nullable;
7 import android.view.View;
8 import android.widget.Button;
9
10 /**
11 * Created by zhang.qiongwen on 2019/8/10.
12 */
13
14 public class page2 extends Activity {
15
16 @Override
17 protected void onCreate(@Nullable Bundle savedInstanceState) {
18 super.onCreate(savedInstanceState);
19
20 setContentView(R.layout.page2);
21
22 Button btn1 = (Button)findViewById(R.id.button1);
23 Button btn2 = (Button)findViewById(R.id.button2);
24
25 btn1.setOnClickListener(new View.OnClickListener() {
26 @Override
27 public void onClick(View view) {
28 Intent i = new Intent(page2.this , page1.class);
29 startActivity(i);
30 }
31 });
32
33 btn2.setOnClickListener(new View.OnClickListener() {
34 @Override
35 public void onClick(View view) {
36 Intent b = new Intent(page2.this , page2.class);
37 startActivity(b);
38 }
39 });
40
41
42 }
43 }
其中使用了intent来连接page1、page2、activity三个事件，分别展示page1.xml和page2.xml，其中page1.java和page2.java都需要来绑定button的点击事件，否则在跳转到page1和page2事件之后无法响应另一个button的点击事件，程序直接关闭，关于intent用法可以参考以下链接https://blog.csdn.net/weixin_38199770/article/details/79391259
另外也可以通过直接判断发生点击事件的Button来响应点击事件，代码如下：
MainActivity.java:
1 package com.example.zhangqiongwen.homework1;
2
3 import android.app.Activity;
4 import android.content.Intent;
5 import android.os.Bundle;
6 import android.support.annotation.Nullable;
7 import android.view.View;
8 import android.view.ViewStructure;
9 import android.widget.Button;
10
11
12 public class MainActivity extends Activity{
13 @Override
14 protected void onCreate(@Nullable Bundle savedInstanceState) {
15 super.onCreate(savedInstanceState);
16 this.setContentView(R.layout.activity_main);
17
18
19
20 }
21
22 public void click(View view){
23 int i = view.getId();
24
25 switch (i){
26
27 case R.id.button1:
28 this.setContentView(R.layout.page1);
29 break;
30
31 case R.id.button2:
32 this.setContentView(R.layout.page2);
33 break;
34
35 }
36 }
37
38 }
另外还有同事给我讲了另外一种思路，将图片和Hellow World文字放在同一个布局文件下，然后按钮点击的作用分别是隐藏TextView、显示ImageView和显示TextView、隐藏ImageView，我在网上进行查找发现似乎要使用ConstrainLayout的布局方式，我现在勉强能够使用Relativelayout布局和Linerlayout布局，问题留存，等待解决。