Android+java程序开发笔记|持续更新
//关闭标题栏 android:theme="@style/Theme.AppCompat.Light.NoActionBar"> //获取文字id状态 TextView lblTitle=(TextView)findViewById(R.id.a1); //获取文本信息 String name=liblTitle.getText().toString(); //修改文字内容 lblTitle.setText("这是显示的内容"); //获取图片id状态 ImageView b=(ImageView)findViewById((R.id.a2)); //修改图片 b.setImageDrawable(getDrawable(R.drawable.huanqi)); //跳转界面 Intent intent=new Intent(MainActivity.this,Main2Activity.class); startActivity(intent); //隐式跳转 Intent intent=new Intent("android.intent.action.MY"); startActivity(intent); //选择性隐式跳转 Intent intent=new Intent("android.intent.action.MY"); intent.setAction(Intent.ACTION_VIEW); intent.setData(Uri.parse("https://www.baidu.com")); startActivity(intent); manifests界面添加内容: <activity android:name=".MainActivity2"> <intent-filter> <action android:name="android.intent.action.MY"/> <category android:name="android.intent.category.DEFAULT"/> </intent-filter> </activity> //等待3秒跳转界面 final Intent intent = new Intent(MainActivity.this, Main2Activity.class); Timer timer = new Timer(); TimerTask task = new TimerTask() { @Override public void run() { startActivity(intent); } }; timer.schedule(task, 3000); //跳转后结束当前界面 finish(); //提示 Toast toast= Toast.makeText(getApplicationContext(),"哈哈", Toast.LENGTH_SHORT); toast.show(); //判断 当dlzh1等于25时执行 if (dlzh1.equals("25")) { } DriverManager类:依据数据库的不同管理jdbc驱动 Connection接口:负责连接数据库并担任传送数据的任务。 Statement 接口:友Connection产生,负责执行sql语句。 ResultSet接口:负责保存Statement执行后所产生的查询结果。 //隐藏标题栏状态栏 requestWindowFeature(Window.FEATURE_NO_TITLE); //隐藏标题栏 getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN); //隐藏状态栏 //放在setContentView(R.layout.activity_main3);前面 //限制输入内容只能为: android:digits="0123456789qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPLKJHGFDSAZXCVBNM" //布局显示 Visibility final TextView textView2= (TextView)findViewById(R.id.text2); int a=textView2.getVisibility(); if (a==8) { textView2.setVisibility(View.VISIBLE); } else { textView2.setVisibility(View.GONE); } 权限 //因特网 <uses-permission android:name="android.permission.INTERNET" /> //移动数据 <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> //WIFI数据 <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
//修改控件长度 ViewGroup.LayoutParams layoutParams=linearLayout.getLayoutParams(); layoutParams.width=100; linearLayout.setLayoutParams(layoutParams); //滑动窗体 滑动窗体使用控件:<androidx.viewpager.widget.ViewPager> ViewPager viewPager = findViewById(R.id.hd); List<View> views = new ArrayList<View>(); LayoutInflater layoutInflater = LayoutInflater.from(getApplicationContext()); View view1 = layoutInflater.inflate(R.layout.activity_main2,null); View view2 = layoutInflater.inflate(R.layout.activity_main3,null); views.add(view1); views.add(view2); //执行GuidPageAdapter.java中的方法 GuidPageAdapter guidPageAdapter = new GuidPageAdapter(views); viewPager.setAdapter(guidPageAdapter); //对指定控件进行操作时添加view1 TextView textView= (TextView)view1.findViewById(R.id.text1); ----------------java文件分解线------------------- //GuidPageAdapter.java文件内容 package com.android.huadong; import android.view.View; import android.view.ViewGroup; import android.widget.TextView; import androidx.annotation.NonNull; import androidx.viewpager.widget.PagerAdapter; import androidx.viewpager.widget.ViewPager; import java.util.List; public class GuidPageAdapter extends PagerAdapter { List<View> views; public GuidPageAdapter(List<View> views) { this.views = views; } @Override //获取当前窗体界面数 public int getCount() { return views.size(); } @Override //判断是否由对象生成界面 public boolean isViewFromObject(@NonNull View view, @NonNull Object object) { return view==object; } @Override //使从ViewGroup中移出当前View public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) { ((ViewPager)container).removeView(views.get(position)); } @NonNull @Override //返回一个对象,这个对象表明了PagerAdapter适配器选择哪个对象放在当前的ViewPager中 public Object instantiateItem(@NonNull ViewGroup container, int position) { ((ViewPager)container).addView(views.get(position)); return views.get(position); } }
java分区————————java分区
//线程 t.start()是执行此线程 Thread t = new Thread(new Runnable(){ public void run(){ }}); t.start(); //获取线程名称 String name = Thread.currentThread().getName();
不知道说什么好,还是祝疫情早点结束吧!
Very informative article. Really thank you! Really Cool. Irina Kendall Votaw
Thank you for your compliment