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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

package com.example.work5_1;

import android.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import android.content.DialogInterface;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    @Override
    public void onBackPressed() {

        AlertDialog.Builder builder=new AlertDialog.Builder(this)
                .setTitle("普通对话框")
                .setMessage("是否退出至主菜单")
//                .setIcon(R.drawable.ic_launcher_background)
                .setPositiveButton("确定", new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                        dialog.dismiss();
                        MainActivity.this.finish();
                    }
                })
                .setNegativeButton("取消", new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                        dialog.dismiss();
                    }
                });
        AlertDialog dialog=builder.create();
        dialog.show();
    }

}

  

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)

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

<!--    <TextView-->
<!--        android:layout_width="wrap_content"-->
<!--        android:layout_height="wrap_content"-->
<!--        android:text="Hello World!"-->
<!--        app:layout_constraintBottom_toBottomOf="parent"-->
<!--        app:layout_constraintLeft_toLeftOf="parent"-->
<!--        app:layout_constraintRight_toRightOf="parent"-->
<!--        app:layout_constraintTop_toTopOf="parent" />-->
    <Button
        android:id="@+id/bt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="请选择你的性别"
        android:layout_marginTop="20dp"
        android:layout_gravity="center"/>

</LinearLayout>
package com.example.work5_2;

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.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    int x = 0;
    private String Arr[] = {"你选择了男","你选择了女"};
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.bt).setOnClickListener(this);

    }
    @Override
    public void onClick(View v){
        AlertDialog dialog;
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("性别");
        builder.setSingleChoiceItems(new String[]{"男", "女"}, 0, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int i) {
                x = i;
//                Toast.makeText(MainActivity.this,Arr[i], Toast.LENGTH_SHORT).show();
            }
        });
        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int i) {
//                final String items[]={"男","女"};
                Toast.makeText(MainActivity.this,Arr[x], Toast.LENGTH_SHORT).show();
                dialog.dismiss();
            }
        });
        builder.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)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="#4CAF50">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="1.TextView显示文本信息"
        android:layout_gravity="center"
        android:layout_marginTop="20dp"
        android:textColor="#F50C0C"/>
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:text="2.按钮"
        android:textColor="#F30808"
        android:background="#ffffff"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="3.编辑框:请输入信息"
        android:textColorHint="#F10A0A"
        android:layout_margin="10dp"/>
    <RadioGroup
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="25dp"
            android:textColor="#F30707"
            android:text="4.男"
            android:layout_marginLeft="10dp"/>
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="25dp"
            android:textColor="#F30707"
            android:text="女"
            android:layout_marginLeft="10dp"/>
    </RadioGroup>
    <CheckBox
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="电脑"
        android:textSize="20sp"
        android:textColor="#F30707"
        android:layout_margin="10dp"/>
    <CheckBox
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="手机"
        android:textSize="20sp"
        android:textColor="#F30707"
        android:layout_marginLeft="10dp"/>
</LinearLayout>

  

 

 

4.教材p76页 图3—17购物商城界面

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
<!--    tools:context=".MainActivity"-->


<!--    <TextView-->
<!--        android:layout_width="match_parent"-->
<!--        android:layout_height="45dp"-->
<!--        android:text=""-->
<!--        android:textSize="18sp"-->
<!--        android:textColor="#ffffff"-->
<!--        android:background="#ff8f03"-->
<!--        android:gravity="center"/>-->

    <ListView
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:listSelector="#fefefefe"
        ></ListView>

</LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:padding="16dp" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ImageView
        android:id="@+id/iv"
        android:layout_width="120dp"
        android:layout_height="90dp"

        android:layout_centerVertical="true"
        ></ImageView>
    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="10dp"

        android:layout_toRightOf="@+id/iv"
        android:layout_centerVertical="true">
        <TextView
            android:id="@+id/title"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:textSize="20sp"
            android:textColor="#000000"
            android:text="桌子"></TextView>
        <TextView
            android:id="@+id/prices"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="20sp"
            android:layout_marginTop="10dp"
            android:layout_below="@+id/title"
            android:text="价格:"></TextView>
        <TextView
            android:id="@+id/price"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="1800"
            android:textSize="20sp"
            android:layout_below="@+id/title"
            android:layout_toRightOf="@+id/prices"
            android:textColor="#BA000000"
            android:layout_marginTop="10dp"></TextView>
    </RelativeLayout>

</RelativeLayout>

  

package com.example.shoppingapp;

import androidx.appcompat.app.AppCompatActivity;
import android.widget.TextView;
import android.widget.ImageView;
import android.widget.BaseAdapter;
import android.view.View;
import android.view.ViewGroup;
//import android.os.Build;
import android.os.Bundle;
//import android.widget.ListAdapter;
import android.widget.ListView;

public class MainActivity extends AppCompatActivity {
    private ListView mListView;
    private String[] titles = {"桌子","苹果","蛋糕","线衣","猕猴桃","围巾"};
    private String[] prices = {"1800元","10元/kg","300元","350"+"元","10元/kg","280元"};
    private int[] icons = {R.drawable.table,R.drawable.apple,R.drawable.cake,R.drawable.wireclothes,R.drawable.kiwifruit,R.drawable.scarf};
//    protected  void onCreate(Build savedInstanceState){
//        super.onCreate(savedInstanceState);
//        setContentView(R.layout.activity_main);
//
//    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mListView = (ListView) findViewById(R.id.lv);
        MyBaseAdapter mAdapter = new MyBaseAdapter();
        mListView.setAdapter(mAdapter);
    }
    class MyBaseAdapter extends BaseAdapter {
        @Override
        public int getCount() {

            return titles.length;
        }
        @Override
        public Object getItem(int position) {

            return titles[position];
        }

        @Override
        public long getItemId(int position) {

            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View view= View.inflate(MainActivity.this, R.layout.list_item, null);
            TextView title = (TextView) view.findViewById(R.id.title);
            TextView price = (TextView) view.findViewById(R.id.price);
            ImageView iv = (ImageView) view.findViewById(R.id.iv);
            title.setText(titles[position]);
            price.setText(prices[position]);
            iv.setBackgroundResource(icons[position]);
            return view;
        }
    }
}

  

 

 

 

  

posted @ 2021-09-27 20:44  Y6  阅读(76)  评论(0)    收藏  举报