安卓第三次作业

1.返回键实现对话框弹出是否退出应用程序

import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.content.DialogInterface;
import android.text.AlteredCharSequence;
import android.view.Menu;

public class MainActivity extends Activity {

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

    }
    @Override
    public void onBackPressed() {
        // TODO Auto-generated method stub
        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) {
                        // TODO Auto-generated method stub
                        dialog.dismiss();
                        MainActivity.this.finish();
                    }
                })
                .setNegativeButton("取消", new DialogInterface.OnClickListener() {

                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // TODO Auto-generated method stub
                        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）

package com.example.a;

 

import android.os.Bundle;

import android.app.Activity;

import android.app.AlertDialog;

import android.app.AliasActivity;

import android.app.Dialog;

import android.content.DialogInterface;

import android.view.Menu;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.Toast;

 

public class MainActivity extends Activity {

 

Button btn;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        

    }

 

 

  public void onclick(View v){

  AlertDialog dialog;

   AlertDialog.Builder builder = new AlertDialog.Builder(this)

   .setIcon(R.drawable.ic_launcher)

   .setTitle("选择")

   .setMessage("选择男女")

   .setPositiveButton("nan", new DialogInterface.OnClickListener() {

 

@Override

public void onClick(DialogInterface dialog, int which) {

// TODO Auto-generated method stub

Toast.makeText(MainActivity.this, "你选择了男", 10).show();

dialog.dismiss();

 

}

})

   .setNegativeButton("nv", new DialogInterface.OnClickListener() {

 

@Override

public void onClick(DialogInterface dialog, int which) {

// TODO Auto-generated method stub

Toast.makeText(MainActivity.this, "你选择了女", 10).show();

dialog.dismiss();

}

});

   dialog=builder.create();

   dialog.show();

  }

  

   

    

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".MainActivity" >

 

    <Button         

        android:layout_height="match_parent"

        android:layout_width="match_parent"

        android:text="按钮"

        android:onClick="onclick"

        />

</RelativeLayout>

3.布局(详见:Android第五周上机word文档)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    tools:context=".MainActivity"
    android:background="#D300FF">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:text="1.TextView显示的文本信息"
        android:textSize="29sp"
        android:layout_marginLeft="40dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="30dp"
        android:textColor="#008EFF"
        />
    <Button
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:text="2.按钮"
        android:textSize="30sp"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="90dp"
        android:textColor="#FF3C00"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="60dp"

        android:text="3.编辑框：请输入信息"
        android:textSize="30sp"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="180dp"
        android:textColor="#000000"/>
    <RadioGroup
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:orientation="horizontal">
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="4.男"
            android:textSize="30sp"
            android:textColor="#FF0F00"
            android:layout_marginTop="250dp"/>
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="女"
            android:textSize="30sp"
            android:textColor="#FFFFFF"
            android:layout_marginTop="250dp"
            />

    </RadioGroup>
    <CheckBox
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="电脑"
        android:textColor="#FF0000"
        android:textSize="30sp"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="300dp"/>
    <CheckBox
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="手机"
        android:textColor="#000000"
        android:textSize="30sp"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp"
        android:layout_marginTop="340dp"/>

</RelativeLayout>

4.教材p76页图3—17购物商城界面

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context=".MainActivity"

android:orientation="vertical">

<TextView

android:layout_height="100dp"

android:layout_width="match_parent"

android:text="1.显示文本信息"

<Button

android:layout_height="100dp"

android:layout_width="100dp"

android:text="2.按钮"

android:onClick="onclick"

<EditText

android:layout_height="100dp"

android:layout_width="match_parent"

android:hint="3.输入文本信息"

<RadioGroup

android:layout_height="wrap_content"