第三次Android作业

一、 返回键实现对话框弹出是否退出应用程序

package itcast.cn;
        import android.app.AlertDialog;
        import android.content.DialogInterface;
        import android.os.Bundle;
        import android.app.Activity;


public class Main2Activity extends Activity {


    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
    }



    public void onBackPressed(){
        AlertDialog dialog;
        AlertDialog.Builder builder=new AlertDialog.Builder(this)
                .setTitle("普通对话框")
                .setIcon(R.drawable.ic_launcher_background)
                .setMessage("是否确定退出")
                .setPositiveButton("确定", new DialogInterface.OnClickListener() {


                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                        Main2Activity.this.finish();}

                })
                .setNegativeButton("取消", new DialogInterface.OnClickListener() {


                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });
        dialog=builder.create();
        dialog.show();
    }

}

 

 

二、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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/bt_1"
        android:layout_width="wrap_content"
        android:layout_height="100dp"
        android:text="单选框"
        android:gravity="center"
        android:layout_marginTop="50dp"
        android:layout_gravity="center">
    </Button>

</LinearLayout>

package itcast.cn;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;


public class Main2Activity extends Activity implements View.OnClickListener{
   private int i=1;
   private int i1[]={1,2};


    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        findViewById(R.id.bt_1).setOnClickListener(this);

    }

    public void onClick(View v){
        AlertDialog dialog;
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("你的性别是？");
        builder.setSingleChoiceItems(new String[]{"女","男"},i,new DialogInterface.OnClickListener(){
            public void onClick(DialogInterface dialog,int which){
                i=which;
            }
        });
        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
               if (i==1){
                   Toast.makeText(Main2Activity.this,"你选择了男",Toast.LENGTH_SHORT).show();
               }else{
                   Toast.makeText(Main2Activity.this,"你选择了女",Toast.LENGTH_SHORT).show();
               }
                dialog.dismiss();
            }
        });
        builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });
        dialog = builder.create();
        dialog.show();

    }

}

 

 

 

 三、实现如下布局界面

<?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:background="#00FF20"
    android:orientation="vertical">

    <TextView
        android:layout_width="200dp"
        android:layout_height="50dp"
        android:text="1.TextView显示文本"
        android:textSize="20dp"
        android:gravity="center"
        android:layout_marginTop="50dp"
        android:layout_gravity="center"
        android:textStyle="italic"
        android:textColor="#C00000">
    </TextView>
    <Button
        android:id="@+id/bt_1"
        android:layout_width="250dp"
        android:layout_height="50dp"
        android:text="2.按钮"
        android:textSize="25dp"
        android:textColor="#C00000"
        android:gravity="center"
        android:layout_gravity="center">
    </Button>
<EditText
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:hint="3.编辑框：请输入信息"
    android:textColorHint="#C00000"
    android:layout_marginLeft="20dp"
    android:textSize="25sp"
    android:textStyle="bold">
</EditText>
   <RadioGroup
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:orientation="horizontal">
       <RadioButton
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:text="4.男"
           android:layout_marginLeft="20dp"
           android:textSize="25dp"
           android:textColor="#C00000">
       </RadioButton>
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textStyle="bold"
            android:text="女"
            android:textSize="25dp"
            android:textColor="#C00000"></RadioButton>
   </RadioGroup>
    <CheckBox
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="电脑"
        android:layout_marginLeft="20dp"
        android:textSize="25dp"
        android:textColor="#C00000"></CheckBox>
    <CheckBox
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="手机"
        android:layout_marginLeft="20dp"
        android:textSize="25dp"
        android:textColor="#C00000"></CheckBox>
</LinearLayout>

 

 4.教材p76页 图3—17购物商城界面

package itcast.cn;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.ImageView;



public class Main2Activity extends Activity{
    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/千克","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(Bundle savedInstancestate){
        super.onCreate(savedInstancestate);
        setContentView(R.layout.activity_main2);
        mListView=(ListView)findViewById(R.id.lv);
        MyBaseAdapter mAdapter =new MyBaseAdapter();
        mListView.setAdapter(mAdapter);
    }
class MyBaseAdapter extends BaseAdapter{
        public int getCount(){
            return titles.length;
        }
        public Object getItem(int position){
            return titles[position];
        }
        public long getItemId(int position) {
        return position;
        }
        public View getView(int position,View convertView,ViewGroup parent){
            View view=View.inflate(Main2Activity.this,R.layout.activity_main3,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;
        }
}




    }

<?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">
    
    <TextView
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:gravity="center"
        android:text="购物商城"
        android:textColor="#CC0000"
        android:textSize="40dp"
        android:background="#33FFFF"></TextView>

    <ListView
        android:id="@+id/lv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"></ListView>
    
</LinearLayout>

<?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">
    <ImageView
        android:layout_width="200dp"
        android:layout_height="200dp"
        android:id="@+id/iv"
        />
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_toRightOf="@id/iv"
        >
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/title"
            android:layout_marginTop="50dp"
            android:layout_marginLeft="15dp"
            />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="价格:"
            android:id="@+id/jg"
            android:layout_below="@id/title"
            android:layout_marginTop="50dp"
            android:layout_marginLeft="15dp"/>
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/price"
            android:layout_toRightOf="@id/jg"
            android:layout_below="@id/title"
            android:layout_marginTop="50dp"
            android:layout_marginLeft="15dp"/>
    </RelativeLayout>
</LinearLayout>