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.myapplication;
import android.app.AlertDialog;

import android.os.Bundle;
import android.app.Activity;
import android.content.DialogInterface;
import android.view.Menu;

public class Assignment03_02 extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity03_02);
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
//        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    
    @Override
    public void onBackPressed() {
        AlertDialog dialog;
        AlertDialog.Builder builder = new AlertDialog.Builder(this)
            .setTitle("是否退出")
            .setMessage("是否退出应用程序 :")
            .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    // TODO Auto-generated method stub
                    dialog.dismiss();
                    Assignment03_02.this.finish();
                }
            })
            .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    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"
    tools:context=".Assignment03_02" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</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）

<?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=".Main3Activity">
    <TextView
        android:id="@+id/tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="您的性别是："
        android:gravity="center"
        android:textSize="20sp"
        android:layout_marginTop="10dp"
        android:textColor="#FFFDB371"/>
    <Button
        android:id="@+id/bt"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="选择性别"
        android:layout_gravity="center"
        android:layout_marginTop="10dp"/>
 
</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)

<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:orientation="vertical"
    tools:context=".Assignment03_04" >
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/textView"
        android:layout_marginTop="25dp"
        android:textSize="25sp"
        android:gravity="center"
        />
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/button"
        android:layout_margin="25dp"
        />
    <EditText
        android:inputType="text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="@string/editText"
        android:gravity="center"
        />
    <RadioGroup
        android:id="@+id/radioGroup"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        >
        <RadioButton
            android:id="@+id/radioButton0"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="25sp"
            android:text="@string/male" 
            />
        <RadioButton
            android:id="@+id/radioButton1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="25sp"
            android:text="@string/female" 
            />
    </RadioGroup>
    <CheckBox
        android:id="@+id/checkBox0"
        android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="25sp"
            android:text="@string/checkBox0"
        />
    <CheckBox
        android:id="@+id/checkBox1"
        android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="25sp"
            android:text="@string/checkBox1"
        />

</LinearLayout>

 

 

4.教材p76页 图3—17购物商城界面