第5.6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 androidx.appcompat.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 dialog;
AlertDialog.Builder builder=new AlertDialog.Builder(this)
.setTitle("普通对话框")
.setIcon(R.mipmap.ic_launcher)
.setMessage("是否退出应用:")
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int i) {
dialog.dismiss();
MainActivity.this.finish();
}
})
.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int i) {
dialog.dismiss();
}
});
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"
tools:context=".SingleChoiceDialog"
android:orientation="vertical">
<TextView
android:id="@+id/tv_1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="单选对话框"
android:gravity="center"
android:layout_marginTop="10dp"
android:textSize="20sp"
android:textStyle="bold"
android:textColor="#000000"
/>
<Button
android:id="@+id/btn_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="选择性别："
android:textSize="20sp"
android:textStyle="bold"
android:textColor="#000000"
android:layout_marginTop="20dp"
android:layout_gravity="center"
/>
</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;
import android.widget.Toast;

public class SingleChoiceDialog extends AppCompatActivity implements View.OnClickListener {
private TextView textView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_single_choice_dialog);
findViewById(R.id.btn_1).setOnClickListener(this);
textView=(TextView)findViewById(R.id.tv_1);
}

@Override
public void onClick(View view) {
AlertDialog dialog ;
AlertDialog.Builder builder=new AlertDialog.Builder(this);
builder.setTitle("性别：");
builder.setIcon(R.mipmap.ic_launcher);
final String[] sexs = new String[]{"男","女"};
builder.setSingleChoiceItems(sexs, 0, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(SingleChoiceDialog.this, "您选择了: " + sexs[which], Toast.LENGTH_LONG).show();
}
});
builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(SingleChoiceDialog.this, "你选择了男", Toast.LENGTH_LONG).show();
}
});
builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
dialog=builder.create();
dialog.show();

}

3.布局(详见:Android第五周上机word文档)

</RadioGroup>
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="电脑"
android:textSize="25dp"
android:textColor="#8E8E8E "
android:checked="true"
android:layout_marginLeft="20dp"
/>
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="手机"
android:textSize="25dp"
android:textColor="#8E8E8E "
android:checked="true"
android:layout_marginLeft="20dp"
/>

</LinearLayout>

4.教材p76页图3—17购物商城界面

<?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">

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="15dp">

</RelativeLayout>
</RelativeLayout>

package com.example.chap8;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.BaseAdapter;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
private ListView mListView;

private String [] titles={"桌子","苹果","蛋糕","线衣"};
private String [] prices={"1800元","10元/kg","300元","350元"};

private int [] icons={R.drawable.table,R.drawable.apple,R.drawable.cake,R.drawable.wireclothes};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mListView = (ListView) findViewById(R.id.lv);
MyBaseAdapter myAdapter = new MyBaseAdapter();
mListView.setAdapter(myAdapter);
}
class MyBaseAdapter extends BaseAdapter{
@Override
public int getCount() {
return titles.length;
}
@Override
public Object getItem(int i) {
return titles[i];
}
@Override
public long getItemId(int i) {
return i;
}

@Override
public View getView(int i, View view, ViewGroup viewGroup) {
View view1= View.inflate(MainActivity.this,R.layout.activity_main2,null);
TextView title = (TextView)view1.findViewById(R.id.title);
TextView price = (TextView)view1.findViewById(R.id.price);
ImageView iv = (ImageView)view1.findViewById(R.id.iv);
title.setText(titles[i]);
price.setText(prices[i]);
iv.setBackgroundResource(icons[i]);
return view;
}
}
}

posted @ 2021-09-25 15:51 刘姝彤阅读(28) 评论(0) 编辑收藏举报

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第5.6作业

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