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 cn.itcast.myapplication;
 2 
 3 import androidx.appcompat.app.ActionBar;
 4 import androidx.appcompat.app.AlertDialog;
 5 import androidx.appcompat.app.AppCompatActivity;
 6 
 7 import android.content.DialogInterface;
 8 import android.os.Bundle;
 9 
10 public class Main5Activity extends AppCompatActivity {
11 
12     @Override
13     protected void onCreate(Bundle savedInstanceState) {
14         super.onCreate(savedInstanceState);
15         setContentView(R.layout.activity_main5);
16     }
17     public void onBackPressed(){
18         AlertDialog dialog;
19         AlertDialog.Builder builder=new AlertDialog.Builder(this);
20         builder.setTitle("普通对话框");
21         builder.setIcon(R.mipmap.ic_launcher);
22         builder.setMessage("是否退出应用");
23         builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
24             @Override
25             public void onClick(DialogInterface dialog,int which) {
26                 dialog.dismiss();
27                 Main5Activity.this.finish();
28             }
29         });
30         
31         builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
32             @Override
33             public void onClick(DialogInterface dialog,int which) {
34               dialog.dismiss();
35             }
36         });
37         dialog=builder.create();
38         dialog.show();
39 
40 
41 
42     }
43 
44 
45 
46 }






 1 <?xml version="1.0" encoding="utf-8"?>
 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     android:layout_height="match_parent"
 4     android:layout_width="match_parent">
 5 <Button
 6     android:layout_width="wrap_content"
 7     android:layout_height="wrap_content"
 8     android:text="按钮1"
 9     android:layout_centerInParent="true"
10     android:background="#777BB9">
11 
12 </Button>
13 </RelativeLayout>






 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（参考书上改字体那个案例）




 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     android:orientation="vertical"
 8     tools:context=".Main3Activity">
 9     <TextView
10         android:id="@+id/tv"
11         android:layout_width="match_parent"
12         android:layout_height="wrap_content"
13         android:text="您的性别是："
14         android:gravity="center"
15         android:textSize="20sp"
16         android:layout_marginTop="10dp"
17         android:textColor="#FFFDB371"/>
18     <Button
19         android:id="@+id/bt"
20         android:layout_width="wrap_content"
21         android:layout_height="wrap_content"
22         android:text="选择性别"
23         android:layout_gravity="center"
24         android:layout_marginTop="10dp"/>
25  
26 </LinearLayout>






package com.example.myapplication;
 
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
 
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
 
public class Main3Activity extends AppCompatActivity implements View.OnClickListener {
    private TextView textView;
    private String[] sexArry= {"男", "女"};
    int sex = 1;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
        findViewById(R.id.bt).setOnClickListener(this);
        textView = (TextView) findViewById(R.id.tv);
    }
 
    @Override
    public void onClick(View v) {
        AlertDialog dialog;
        AlertDialog.Builder builder=new AlertDialog.Builder(this)
                .setTitle("选择性别")
                .setIcon(R.mipmap.ic_launcher)
                .setSingleChoiceItems(new String[]{"男", "女"}, sex, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int i) {
                        sex=i;
                    }
                })
                .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int i) {
                        dialog.dismiss();//关闭对话框
                        if (sex==1){
                            textView.setText("您的性别是：女");
                        }else{
                            textView.setText("您的性别是：男");
                        }
                    }
                })
                //t添加"取消"按钮
                .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int i) {
                        dialog.dismiss();
                    }
                });
        dialog=builder.create();
        dialog.show();
    }
}






 


 


 3.布局(详见:Android第五周上机word文档)


 




 1 package com.example.myapplication;
 2 
 3 import android.os.Bundle;
 4 import android.app.Activity;
 5 
 6 public class Assignment03_04 extends Activity {
 7     int gender = 0;
 8     
 9     @Override
10     protected void onCreate(Bundle savedInstanceState) {
11         super.onCreate(savedInstanceState);
12         setContentView(R.layout.activity03_04);
13     }
14 }






 1 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 2     xmlns:tools="http://schemas.android.com/tools"
 3     android:layout_width="match_parent"
 4     android:layout_height="match_parent"
 5     android:orientation="vertical"
 6     tools:context=".Assignment03_04" >
 7     <TextView
 8         android:layout_width="match_parent"
 9         android:layout_height="wrap_content"
10         android:text="@string/textView"
11         android:layout_marginTop="25dp"
12         android:textSize="25sp"
13         android:gravity="center"
14         />
15     <Button
16         android:layout_width="match_parent"
17         android:layout_height="wrap_content"
18         android:text="@string/button"
19         android:layout_margin="25dp"
20         />
21     <EditText
22         android:inputType="text"
23         android:layout_width="match_parent"
24         android:layout_height="wrap_content"
25         android:hint="@string/editText"
26         android:gravity="center"
27         />
28     <RadioGroup
29         android:id="@+id/radioGroup"
30         android:layout_width="wrap_content"
31         android:layout_height="wrap_content"
32         android:orientation="horizontal"
33         >
34         <RadioButton
35             android:id="@+id/radioButton0"
36             android:layout_width="wrap_content"
37             android:layout_height="wrap_content"
38             android:textSize="25sp"
39             android:text="@string/male" 
40             />
41         <RadioButton
42             android:id="@+id/radioButton1"
43             android:layout_width="wrap_content"
44             android:layout_height="wrap_content"
45             android:textSize="25sp"
46             android:text="@string/female" 
47             />
48     </RadioGroup>
49     <CheckBox
50         android:id="@+id/checkBox0"
51         android:layout_width="wrap_content"
52             android:layout_height="wrap_content"
53             android:textSize="25sp"
54             android:text="@string/checkBox0"
55         />
56     <CheckBox
57         android:id="@+id/checkBox1"
58         android:layout_width="wrap_content"
59             android:layout_height="wrap_content"
60             android:textSize="25sp"
61             android:text="@string/checkBox1"
62         />
63 
64 </LinearLayout>






 4.




 1 package com.example.myapplication;
 2 
 3 import android.os.Bundle;
 4 import android.view.View;
 5 import android.view.ViewGroup;
 6 import android.widget.BaseAdapter;
 7 import android.widget.ImageView;
 8 import android.widget.ListView;
 9 import android.widget.TextView;
10 
11 import androidx.appcompat.app.AppCompatActivity;
12 
13 public class Assignment03_01 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元/kg", "300元", "350元", "10元/kg", "280元" };
17 
18     private int[] icons = { R.drawable.ic_launcher_foreground, R.drawable.ic_launcher_foreground,  R.drawable.ic_launcher_foreground, R.drawable.ic_launcher_foreground,  R.drawable.ic_launcher_foreground, R.drawable.ic_launcher_foreground };
19 
20     @Override
21     protected void onCreate(Bundle savedInstanceState) {
22         super.onCreate(savedInstanceState);
23         setContentView(R.layout.activity03_01);
24         mListView = findViewById(R.id.listView);
25         MyBaseAdapter mAdapter = new MyBaseAdapter();
26         mListView.setAdapter(mAdapter);
27     }
28     class ViewHolder {
29         TextView textViewTitle;
30         TextView textViewContent;
31         ImageView imageView;
32     }
33     class MyBaseAdapter extends BaseAdapter {
34         @Override
35         public int getCount() {
36             return titles.length;
37         }
38         @Override
39         public Object getItem(int position) {
40             return titles[position];
41         }
42         @Override
43         public long getItemId(int position) {
44             return position;
45         }
46         @Override
47         public View getView(int position, View convertView, ViewGroup parent) {
48             ViewHolder holder = null;
49             if (convertView == null) {
50                 convertView = View.inflate(Assignment03_01.this, R.layout.list_item, null);
51                 holder = new ViewHolder();
52                 holder.textViewTitle = convertView.findViewById(R.id.textViewTitle);
53                 holder.textViewContent = convertView.findViewById(R.id.textViewContent);
54                 holder.imageView = convertView.findViewById(R.id.imageView);
55             }
56             else {
57                 holder = (ViewHolder)convertView.getTag();
58             }
59             holder.textViewTitle.setText(titles[position]);
60             holder.textViewContent.setText(prices[position]);
61             holder.imageView.setBackgroundResource(icons[position]);
62             return convertView;
63         }
64     }
65 }






 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout
 3     xmlns:android="http://schemas.android.com/apk/res/android"
 4     android:layout_width="match_parent"
 5     android:layout_height="match_parent"
 6     android:orientation="horizontal">
 7     <ImageView
 8         android:id="@+id/imageView"
 9         android:layout_width="wrap_content"
10         android:layout_height="wrap_content">
11 
12     </ImageView>
13     <LinearLayout
14         android:layout_width="wrap_content"
15         android:layout_height="match_parent"
16         android:orientation="vertical">
17         <TextView
18             android:id="@+id/textViewTitle"
19             android:layout_width="wrap_content"
20             android:layout_height="wrap_content"
21             android:textSize="16sp"
22             android:paddingTop="25dp">
23         </TextView>
24         <TextView
25             android:id="@+id/textViewContent"
26             android:layout_width="wrap_content"
27             android:layout_height="wrap_content"
28             android:textSize="11sp">
29         </TextView>
30     </LinearLayout>
31 
32 </LinearLayout>






 


 






            

            
posted @ 
2021-09-26 17:44 
计算机1905geng 
阅读(26) 
评论(0) 
 
收藏 
举报