android第三次作业

1.返回键实现对话框弹出是否退出应用程序

 1 package com.example.ggr;
 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     }
17 
18     @Override
19     public void onBackPressed() {
20         final AlertDialog dialog;
21         AlertDialog.Builder builder=new AlertDialog.Builder(this)
22                 .setTitle("普通对话框")//设置对话框标题
23                 .setIcon(R.mipmap.ic_launcher)//设置设置标题图标
24                 .setMessage("是否确定退出应用：")//设置对话框的提示信息
25                 //添加"确定"按钮
26                 .setPositiveButton("确定", new DialogInterface.OnClickListener() {
27                     @Override
28                     public void onClick(DialogInterface dialog, int i) {
29                         dialog.dismiss();//关闭对话框
30                         MainActivity.this.finish();//关闭MainActivity
31                     }
32                 })
33                 //t添加"取消"按钮
34                 .setNegativeButton("取消", new DialogInterface.OnClickListener() {
35                     @Override
36                     public void onClick(DialogInterface dialog, int i) {
37                         dialog.dismiss();
38                     }
39                 });
40         dialog=builder.create();
41         dialog.show();
42 
43     }
44 }

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     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical">
 6 
 7     <TextView
 8         android:id="@+id/tv"
 9         android:gravity="center"
10         android:layout_width="match_parent"
11         android:layout_height="wrap_content"
12         android:layout_marginTop="20dp"
13         android:text="单选对话框" />
14 
15     <Button
16         android:onClick="onclick1"
17         android:layout_width="match_parent"
18         android:layout_height="wrap_content"
19         android:layout_marginTop="20dp"
20         android:text="选择男女"/>
21 
22 </LinearLayout>

 1 package com.example.ggr;
 2 
 3 
 4 import android.os.Bundle;
 5 import android.app.Activity;
 6 import android.app.AlertDialog;
 7 import android.app.AlertDialog.Builder;
 8 import android.content.DialogInterface;
 9 import android.content.DialogInterface.OnClickListener;
10 import android.view.View;
11 import android.widget.Toast;
12 
13 public class MainActivity extends Activity {
14 
15     @Override
16     protected void onCreate(Bundle savedInstanceState) {
17         super.onCreate(savedInstanceState);
18         setContentView(R.layout.activity_main);
19 
20     }
21 
22     public void onclick1(View view) {
23         AlertDialog.Builder builder = new Builder(this);
24         builder.setIcon(android.R.drawable.ic_dialog_info);
25         builder.setTitle("请选择性别");
26         final String[] items = new String[]{"男", "女"};
27         builder.setSingleChoiceItems(items, -1, new OnClickListener() {
28 
29             @Override
30             public void onClick(DialogInterface dialog, int which) {
31                 Toast.makeText(MainActivity.this, "您选择的是:" + items[which], Toast.LENGTH_SHORT).show();
32                 dialog.dismiss();
33 
34             }
35         });
36         builder.show();
37     }
38 }

3.布局(详见:Android第五周上机word文档)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="#81F781">

    <TextView
        android:id="@+id/tv"
        android:gravity="center"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:text="1.textview显示文本信息"
        android:textColor="#0101DF"
        android:textSize="36dp"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="2.按钮"
        android:textColor="#0101DF"
        android:textSize="36dp"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="输入信息"
        android:textColor="#0101DF"
        android:textSize="36dp"/>
    <RadioGroup
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />
    <RadioButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="男"
        android:textColor="#0101DF"
        android:textSize="36dp"/>
    <RadioButton
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="女"
        android:textColor="#0101DF"
        android:textSize="36dp"/>
    <CheckBox
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="电脑"
        android:textColor="#0101DF"
        android:textSize="36dp"/>
    <CheckBox
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="手机"
        android:textColor="#0101DF"
        android:textSize="36dp"/>
    
</LinearLayout>

4.教材p76页图3—17购物商城界面

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical">
 6 
 7     <TextView
 8         android:layout_width="match_parent"
 9         android:layout_height="45dp"
10         android:text="购物商城"
11         android:textSize="18sp"
12         android:background="#FF8F03"
13         android:gravity="center"/>
14     <ListView
15         android:id="@+id/lv"
16         android:layout_width="match_parent"
17         android:layout_height="wrap_content"/>
18 
19 </LinearLayout>

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent">
 5 
 6     <ImageView
 7         android:layout_width="120dp"
 8         android:layout_height="90dp"
 9         android:id="@+id/iv"
10         android:layout_centerVertical="true"/>
11     <RelativeLayout
12         android:layout_width="wrap_content"
13         android:layout_height="wrap_content"
14         android:layout_marginLeft="10dp"
15         android:layout_toRightOf="@+id/iv"
16         android:layout_centerVertical="true">
17         <TextView
18             android:layout_width="wrap_content"
19             android:layout_height="wrap_content"
20             android:id="@+id/title"
21             android:text="桌子"
22             android:textSize="20sp"
23             android:textColor="#000000"
24             />
25         <TextView
26             android:layout_width="wrap_content"
27             android:layout_height="wrap_content"
28             android:id="@+id/tv_price"
29             android:text="价格"
30             android:layout_below="@id/title"
31             android:layout_marginTop="10dp"
32             android:textSize="20sp"
33             android:textColor="#FF8F03"
34             />
35         <TextView
36             android:layout_width="wrap_content"
37             android:layout_height="wrap_content"
38             android:id="@+id/price"
39             android:text="1000"
40             android:textSize="20sp"
41             android:layout_below="@id/title"
42             android:layout_toRightOf="@id/tv_price"
43             android:layout_marginTop="10dp"
44             android:textColor="#FF8F03"
45             />
46     </RelativeLayout>
47 
48 
49 </LinearLayout>

 1 package com.example.ggr;
 2 
 3 import androidx.appcompat.app.AppCompatActivity;
 4 import android.os.Bundle;
 5 import android.view.View;
 6 import android.view.ViewGroup;
 7 import android.widget.BaseAdapter;
 8 import android.widget.ImageView;
 9 import android.widget.ListAdapter;
10 import android.widget.ListView;
11 import android.widget.TextView;
12 
13 public class MainActivity extends AppCompatActivity {
14     private ListView mListView;
15     private String[] titles = {"桌子", "苹果", "蛋糕", "线衣", "猕猴桃", "围巾"};
16     private String[] prices = {"1800元", "10/kg", "300元", "350元", "10/kg", "280元"};
17     private int[] icons = {R.drawable.table, R.drawable.apple, R.drawable.cake,R.drawable.wrieclothes, R.drawable.kiwifruit, R.drawable.scarf};
18 
19     @Override
20     protected void onCreate(Bundle savedInstanceState) {
21         super.onCreate(savedInstanceState);
22         setContentView(R.layout.activity_main);
23         mListView = (ListView) findViewById(R.id.lv);
24         MyBaseAdapter mAdapter = new MyBaseAdapter();
25         mListView.setAdapter( mAdapter);
26     }
27     class MyBaseAdapter extends BaseAdapter {
28 
29         @Override
30         public int getCount() {
31             return titles.length;
32         }
33 
34         @Override
35         public Object getItem(int i) {
36             return titles[i];
37         }
38 
39         @Override
40         public long getItemId(int i) {
41             return i;
42         }
43 
44         @Override
45         public View getView(int i, View view, ViewGroup viewGroup) {
46             view = View.inflate(MainActivity.this, R.layout.activity_main2, null);
47             TextView title = view.findViewById(R.id.title);
48             TextView price = view.findViewById(R.id.price);
49             ImageView iv = view.findViewById(R.id.iv);
50             title.setText(titles[i]);
51             price.setText(prices[i]);
52             iv.setImageResource(icons[i]);
53             return view;
54         }
55     }
56 }

posted @ 2021-09-25 19:28 葛广瑞阅读(24) 评论(0) 编辑收藏举报

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android第三次作业

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