Android第五、六周作业

1.返回键实现对话框弹出是否退出应用程序

 1 package com.example.lwk;
 2 
 3 import androidx.appcompat.app.AlertDialog;
 4 import androidx.appcompat.app.AppCompatActivity;
 5 
 6 import android.content.DialogInterface;
 7 import android.os.Bundle;
 8 
 9 public class MainActivity extends AppCompatActivity {
10 
11     @Override
12     protected void onCreate(Bundle savedInstanceState) {
13         super.onCreate(savedInstanceState);
14         setContentView(R.layout.activity_main);
15     }
16     @Override
17     public void onBackPressed() {
18         AlertDialog dialog;
19         AlertDialog.Builder builder=new AlertDialog.Builder(this)
20                 .setTitle("普通对话框")
21                 .setIcon(R.mipmap.ic_launcher)
22                 .setMessage("是否确定退出应用:")
23                 .setPositiveButton("确定", new DialogInterface.OnClickListener() {
24                     @Override
25                     public void onClick(DialogInterface dialog, int which) {
26                         dialog.dismiss();
27                         MainActivity.this.finish();
28                     }
29                 })
30                 .setNegativeButton("取消", new DialogInterface.OnClickListener() {
31                     @Override
32                     public void onClick(DialogInterface dialog, int which) {
33                         dialog.dismiss();
34                     }
35                 });
36         dialog=builder.create();
37         dialog.show();
38 
39     }
40 }

 

2.实现以下场景:从一个activity中点击一个按钮后,弹出一个单选按钮对话框,上面有“男”“女”两个选项,选定后,TOAST弹出 你选择了男,或你选择了女(参考书上改字体)

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout 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     android:orientation="vertical">
 9 
10     <TextView
11         android:id="@+id/tv_1"
12         android:layout_width="match_parent"
13         android:layout_height="wrap_content"
14         android:text="单选对话框"
15         android:gravity="center"
16         android:layout_marginTop="20dp"
17         android:textSize="20sp"
18         android:textColor="#474141"
19         android:textStyle="bold"/>
20     <Button
21         android:id="@+id/bt_1"
22         android:layout_width="wrap_content"
23         android:layout_height="wrap_content"
24         android:text="请选择你的性别"
25         android:layout_marginTop="20dp"
26         android:layout_gravity="center"
27         android:textSize="20sp"
28         android:textStyle="bold"
29         android:textColor="#474141"/>
30 </LinearLayout>
 1 package com.example.homework8;
 2 
 3 import androidx.appcompat.app.AlertDialog;
 4 import androidx.appcompat.app.AppCompatActivity;
 5 
 6 import android.content.DialogInterface;
 7 import android.os.Build;
 8 import android.os.Bundle;
 9 import android.view.View;
10 import android.widget.TextView;
11 import android.widget.Toast;
12 
13 import java.util.Locale;
14 
15 public class MainActivity extends AppCompatActivity implements View.OnClickListener{
16     private TextView textView;
17     final String [] sexs=new String[]{"男","女"};
18     @Override
19     protected void onCreate(Bundle savedInstanceState) {
20         super.onCreate(savedInstanceState);
21         setContentView(R.layout.activity_main);
22         findViewById(R.id.bt_1).setOnClickListener(this);
23         textView=(TextView) findViewById(R.id.tv_1);
24 
25     }
26     public void onClick(View view){
27         AlertDialog dialog;
28         AlertDialog.Builder builder=new AlertDialog.Builder(this);
29         builder.setTitle("请选择你的性别:");
30         builder.setIcon(R.mipmap.ic_launcher);
31         builder.setSingleChoiceItems(sexs, 1, new DialogInterface.OnClickListener() {
32             @Override
33             public void onClick(DialogInterface dialog, int which) {
34                 Toast.makeText(MainActivity.this,"您选择的是:"+sexs[which],Toast.LENGTH_LONG).show();
35                 dialog.dismiss();
36             }
37         });
38         builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
39             @Override
40             public void onClick(DialogInterface dialog, int which) {
41                 Toast.makeText(MainActivity.this,"您选择了"+sexs[which],Toast.LENGTH_LONG).show();
42                 dialog.dismiss();
43             }
44         })
45                 .setNegativeButton("取消", new DialogInterface.OnClickListener() {
46                     @Override
47                     public void onClick(DialogInterface dialog, int which) {
48                         dialog.dismiss();
49                     }
50                 });
51         dialog=builder.create();
52         dialog.show();
53     }
54 }

 

3.布局(详见:Android第五周上机word文档)

 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=".MainActivity"
 8     android:background="#25FA2A"
 9     android:layout_margin="5dp">
10 
11     <TextView
12         android:id="@+id/tv_1"
13         android:layout_width="match_parent"
14         android:layout_height="wrap_content"
15         android:text="1.TextView显示文本信息"
16         android:textColor="#F81606"
17         android:textSize="20sp"
18         android:textStyle="italic"
19         android:gravity="center"
20         android:layout_marginTop="20dp"/>
21     <Button
22         android:id="@+id/bu_1"
23         android:layout_width="360dp"
24         android:layout_height="wrap_content"
25         android:text="2.按钮"
26         android:textColor="#F81606"
27         android:textSize="20sp"
28         android:textStyle="bold"
29         android:layout_centerHorizontal="true"
30         android:layout_below="@id/tv_1"
31         android:padding="10dp"/>
32     <EditText
33         android:id="@+id/et_1"
34         android:layout_width="match_parent"
35         android:layout_height="wrap_content"
36         android:hint="3.编辑框:请输入信息"
37         android:textColorHint="#F81606"
38         android:textSize="20sp"
39         android:layout_below="@id/bu_1"
40         android:layout_alignStart="@id/bu_1"
41         android:layout_margin="5dp"
42         android:padding="10dp"/>
43     <RadioGroup
44         android:id="@+id/rg_1"
45         android:layout_width="wrap_content"
46         android:layout_height="wrap_content"
47         android:layout_below="@id/et_1"
48         android:layout_alignLeft="@id/et_1"
49         android:orientation="horizontal"
50         android:padding="5dp">
51 
52     <RadioButton
53         android:id="@+id/rb_1"
54         android:layout_width="wrap_content"
55         android:layout_height="wrap_content"
56         android:text="4.男"
57         android:textSize="20sp"
58         android:textColor="#F81606" />
59     <RadioButton
60         android:id="@+id/rb_2"
61         android:layout_width="wrap_content"
62         android:layout_height="wrap_content"
63         android:text="女"
64         android:textSize="20sp"
65         android:textColor="#F81606" />
66     </RadioGroup>
67     <LinearLayout
68         android:layout_width="match_parent"
69         android:layout_height="match_parent"
70         android:orientation="vertical"
71         android:layout_below="@id/rg_1"
72         android:layout_alignLeft="@id/rg_1">
73     <CheckBox
74         android:id="@+id/ck_1"
75         android:layout_width="wrap_content"
76         android:layout_height="wrap_content"
77         android:text="电脑"
78         android:textSize="20sp"
79         android:textColor="#F81606"
80         android:padding="5dp" />
81     <CheckBox
82         android:id="@+id/ck_2"
83         android:layout_width="wrap_content"
84         android:layout_height="wrap_content"
85         android:text="手机"
86         android:textSize="20sp"
87         android:textColor="#F81606"
88         android:padding="5dp"/>
89     </LinearLayout>
90 
91 </RelativeLayout>

 

4.教材p76页 图3—17购物商城界面

 

 1 activity_main.xml:<?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout 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     android:orientation="vertical">
 9     <TextView
10         android:id="@+id/tv"
11         android:layout_width="match_parent"
12         android:layout_height="50dp"
13         android:text="购物商城"
14         android:textColor="#E8E3E9"
15         android:background="#C175CE"
16         android:textSize="20sp"
17         android:gravity="center"/>
18     <ListView
19         android:id="@+id/lv"
20         android:layout_width="match_parent"
21         android:layout_height="wrap_content"/>
22 
23 </LinearLayout>

 

 

 1 list_item.xml:<?xml version="1.0" encoding="utf-8"?>
 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:orientation="vertical"
 4     android:layout_width="match_parent"
 5     android:layout_height="match_parent"
 6     android:padding="15dp">
 7 
 8     <ImageView
 9         android:id="@+id/iv"
10         android:layout_width="100dp"
11         android:layout_height="80dp"
12         android:layout_centerVertical="true"/>
13     <RelativeLayout
14         android:layout_width="wrap_content"
15         android:layout_height="wrap_content"
16         android:layout_centerVertical="true"
17         android:layout_marginLeft="10dp"
18         android:layout_toRightOf="@id/iv">
19     <TextView
20         android:id="@+id/title"
21         android:layout_width="wrap_content"
22         android:layout_height="wrap_content"
23         android:text="桌子"
24         android:textSize="20sp"
25         android:textColor="#4B4343"/>
26         <TextView
27             android:id="@+id/tv_p"
28             android:layout_width="wrap_content"
29             android:layout_height="wrap_content"
30             android:text="价格"
31             android:textSize="20sp"
32             android:textColor="#F5A631"
33             android:layout_below="@id/title"
34             android:layout_marginTop="10dp"/>
35         <TextView
36             android:id="@+id/price"
37             android:layout_width="wrap_content"
38             android:layout_height="wrap_content"
39             android:text="1800"
40             android:textSize="20sp"
41             android:textColor="#F5A631"
42            android:layout_below="@id/title"
43             android:layout_toRightOf="@id/tv_p"
44             android:layout_marginTop="10dp"/>
45 
46     </RelativeLayout>
47 </RelativeLayout>
 1 package com.example.chap07;
 2 
 3 import androidx.appcompat.app.AppCompatActivity;
 4 
 5 import android.os.Bundle;
 6 import android.view.View;
 7 import android.view.ViewGroup;
 8 import android.widget.BaseAdapter;
 9 import android.widget.ImageView;
10 import android.widget.ListView;
11 import android.widget.TextView;
12 
13 public class MainActivity extends AppCompatActivity {
14     private ListView mListView;
15     //商品名称与价格数据集合
16     private String [] titles={"桌子","苹果","蛋糕","线衣","猕猴桃","围巾"};
17     private String [] prices={"1800元","10元/kg","300元","350元","10元/kg","280元"};
18     //图片数据集合
19     private int [] icons={R.drawable.table,R.drawable.apple,R.drawable.cake,R.drawable.wireclothes,R.drawable.kiwifruit,R.drawable.scarf};
20     @Override
21     protected void onCreate(Bundle savedInstanceState) {
22         super.onCreate(savedInstanceState);
23         setContentView(R.layout.activity_main);
24         mListView = (ListView) findViewById(R.id.lv);//初始化ListView控件
25         MyBaseAdapter myAdapter = new MyBaseAdapter();//创建一个Adapter实例
26         mListView.setAdapter(myAdapter);//设置Adapter
27     }
28     class MyBaseAdapter extends BaseAdapter{
29         @Override
30         public int getCount() {    //获取item的总数
31             return titles.length;  //返回ListView Item条目的总数
32         }
33         @Override
34         public Object getItem(int i) {
35             return titles[i];  //返回Item的数据对象
36         }
37         @Override
38         public long getItemId(int i) {
39             return i;   //返回Item的id
40         }
41         //得到Item的View视图
42         @Override
43         public View getView(int i, View view, ViewGroup viewGroup) {
44            View view1= View.inflate(MainActivity.this,R.layout.list_item,null);
45             TextView title = (TextView)view1.findViewById(R.id.title);
46             TextView price = (TextView)view1.findViewById(R.id.price);
47             ImageView iv = (ImageView)view1.findViewById(R.id.iv);
48             title.setText(titles[i]);
49             price.setText(prices[i]);
50             iv.setBackgroundResource(icons[i]);
51             return view1;
52         }
53     }
54 }

 

posted @ 2021-09-26 17:36  Lwk36  阅读(32)  评论(0编辑  收藏  举报