基础控件(ListView,RecyclerView,单位和尺寸,ViewPager,ViewPager2)
ListView
- list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="vertical"
xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:id="@+id/tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="30sp"
android:text="haha"/>
</LinearLayout>
- activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="vertical"
xmlns:android="http://schemas.android.com/apk/res/android">
<ListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
- Bean.java
package com.example.mylistview;
public class Bean {
String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
- MainActivity.java
package com.example.mylistview;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private List<Bean> data = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
for (int i = 0; i < 100; i++) {
Bean bean = new Bean();
bean.setName("haha" + i);
data.add(bean);
}
ListView listView = findViewById(R.id.lv);
listView.setAdapter(new MyAdapter(data, this));
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Log.e("wmj", "onItemClick:" + i);
}
});
}
}
- 普通版MyAdapter.java
package com.example.mylistview;
import android.content.Context;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import java.util.List;
public class MyAdapter extends BaseAdapter {
private List<Bean> data;
private Context context;
public MyAdapter(List<Bean> data, Context context) {
this.data = data;
this.context = context;
}
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int i) {
return null;
}
@Override
public long getItemId(int i) {
return i;
}
// 每显示一个item都会调用一次
@Override
public View getView(int i, View view, ViewGroup viewGroup) {
if(view == null){
view = LayoutInflater.from(context).inflate(R.layout.list_item, viewGroup, false);
}
TextView textView = view.findViewById(R.id.tv);
textView.setText(data.get(i).getName());
Log.e("wmj", "getView:" + i);
return view;
}
}
- 优化后的My Adapter.java，减少findviewbyid的时间
package com.example.mylistview;
import android.content.Context;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import java.util.List;
public class MyAdapter extends BaseAdapter {
private List<Bean> data;
private Context context;
public MyAdapter(List<Bean> data, Context context) {
this.data = data;
this.context = context;
}
@Override
public int getCount() {
return data.size();
}
@Override
public Object getItem(int i) {
return null;
}
@Override
public long getItemId(int i) {
return i;
}
// 每显示一个item都会调用一次
@Override
public View getView(int i, View view, ViewGroup viewGroup) {
ViewHolder viewHolder;
if(view == null){
// viewHolder和view都只要创建一个就行，反复使用
viewHolder = new ViewHolder();
view = LayoutInflater.from(context).inflate(R.layout.list_item, viewGroup, false);
viewHolder.textView = view.findViewById(R.id.tv);
view.setTag(viewHolder);
}else{
// 如果view已存在，就从服用之前的viewHolder
viewHolder = (ViewHolder) view.getTag();
}
viewHolder.textView.setText(data.get(i).getName());
Log.e("wmj", "getView:" + i);
return view;
}
private final class ViewHolder{
TextView textView;
}
}
RecyclerView
- 在build.gradle中添加依赖：implementation 'androidx.recyclerview:recyclerview:1.1.0'
- recyclerview_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="vertical"
xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:id="@+id/tv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:textSize="30sp"
android:text="haha"/>
</LinearLayout>
- activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="vertical"
xmlns:android="http://schemas.android.com/apk/res/android">
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/rv"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
- Bean.java
package com.example.myrecyclerview;
public class Bean {
String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
- MainActivity.java
package com.example.myrecyclerview;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.StaggeredGridLayoutManager;
import android.os.Bundle;
import android.util.Log;
import android.widget.LinearLayout;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private List<Bean> data = new ArrayList<>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
for (int i = 0; i < 100; i++) {
Bean bean = new Bean();
bean.setName("haha" + i);
data.add(bean);
}
RecyclerView recyclerView = findViewById(R.id.rv);
// 设置布局
// LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
// linearLayoutManager.setOrientation(LinearLayoutManager.HORIZONTAL);
// recyclerView.setLayoutManager(linearLayoutManager);
// 参数2是指一行几个
// GridLayoutManager gridLayoutManager = new GridLayoutManager(this, 3);
// recyclerView.setLayoutManager(gridLayoutManager);
StaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(3, LinearLayout.VERTICAL);
recyclerView.setLayoutManager(staggeredGridLayoutManager);
MyAdapter myAdapter = new MyAdapter(data, this);
recyclerView.setAdapter(myAdapter);
myAdapter.setOnRecyclerItemClickListener(new MyAdapter.OnRecyclerItemClickListener() {
@Override
public void onRecyclerItemClick(int position) {
Log.e("wmj", "onRecyclerItemClick:" + position);
Toast.makeText(MainActivity.this, String.valueOf(position), Toast.LENGTH_SHORT).show();
}
});
}
}
- MyAdapter.java
package com.example.myrecyclerview;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.List;
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
private List<Bean> data;
private Context context;
public MyAdapter(List<Bean> data, Context context) {
this.data = data;
this.context = context;
}
@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = View.inflate(context, R.layout.recyclerview_item, null);
return new MyViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull MyAdapter.MyViewHolder holder, int position) {
holder.tv.setText(data.get(position).getName());
}
@Override
public int getItemCount() {
return data == null ? 0 : data.size();
}
public class MyViewHolder extends RecyclerView.ViewHolder{
private TextView tv;
public MyViewHolder(@NonNull View itemView) {
super(itemView);
tv = itemView.findViewById(R.id.tv);
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(onRecyclerItemClickListener != null){
// 执行接口里的监听方法
onRecyclerItemClickListener.onRecyclerItemClick(getAdapterPosition());
}
}
});
}
}
// 点击监听
private OnRecyclerItemClickListener onRecyclerItemClickListener;
// 给外部设置监听的方法
public void setOnRecyclerItemClickListener(OnRecyclerItemClickListener onRecyclerItemClickListener) {
this.onRecyclerItemClickListener = onRecyclerItemClickListener;
}
public interface OnRecyclerItemClickListener{
void onRecyclerItemClick(int position);
}
}
单位和尺寸
package com.example.mylayoutparams;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.activity_main);
LinearLayout linearLayout = new LinearLayout(this);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT);
linearLayout.setLayoutParams(layoutParams);
TextView textView = new TextView(this);
textView.setText("文本框");
textView.setBackgroundColor(0xffff0000);
// 单位默认是像素px
ViewGroup.LayoutParams textLayoutParams = new LinearLayout.LayoutParams(300,300);
// textView.setLayoutParams(textLayoutParams);
// linearLayout.addView(textView);
linearLayout.addView(textView, textLayoutParams);
setContentView(linearLayout);
}
}
ViewPager
- 定义一个viewpager
- 为viewpager构建Adapter
- layout1.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="vertical"
android:background="#00ff00"
xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="layout1"
android:textSize="30sp"/>
</LinearLayout>
- activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="vertical"
xmlns:android="http://schemas.android.com/apk/res/android">
<androidx.viewpager.widget.ViewPager
android:id="@+id/vp"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
- MainActivity.java
package com.example.myviewpager;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager.widget.ViewPager;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LayoutInflater lf = getLayoutInflater().from(this);
View view1 = lf.inflate(R.layout.layout1, null);
View view2 = lf.inflate(R.layout.layout2, null);
View view3 = lf.inflate(R.layout.layout3, null);
List<View> viewList = new ArrayList<>();
viewList.add(view1);
viewList.add(view2);
viewList.add(view3);
ViewPager viewPager = findViewById(R.id.vp);
MyAdapter myAdapter = new MyAdapter(viewList);
viewPager.setAdapter(myAdapter);
}
}
- MyAdapter.java
package com.example.myviewpager;
import android.view.View;
import android.view.ViewGroup;
import androidx.annotation.NonNull;
import androidx.viewpager.widget.PagerAdapter;
import java.util.List;
public class MyAdapter extends PagerAdapter {
List<View> mListView;
public MyAdapter(List<View> mListView) {
this.mListView = mListView;
}
@Override
public int getCount() {
return mListView.size();
}
// 将给定位置的view添加到viewgroup容器中，创建并显示出来
@NonNull
@Override
public Object instantiateItem(@NonNull ViewGroup container, int position) {
container.addView(mListView.get(position), 0);
return mListView.get(position);
}
@Override
public boolean isViewFromObject(View view,Object object) {
return view == object;
}
@Override
public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
container.removeView(mListView.get(position));
}
}
ViewPager2
- 添加依赖：implementation 'androidx.viewpager2:viewpager2:1.0.0'
- activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_height="match_parent"
android:layout_width="match_parent"
android:orientation="vertical"
xmlns:android="http://schemas.android.com/apk/res/android">
<androidx.viewpager2.widget.ViewPager2
android:id="@+id/vp"
android:background="#ffff00"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
- item_pager.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout android:layout_height="match_parent"
android:layout_width="match_parent"
android:id="@+id/container"
xmlns:android="http://schemas.android.com/apk/res/android">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:id="@+id/tvTitle"
android:text="haha"
android:textColor="#ff0000"/>
</RelativeLayout>
- MainActivity.java
package com.example.myviewpager2;
import androidx.appcompat.app.AppCompatActivity;
import androidx.viewpager2.widget.ViewPager2;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager2 viewPager = findViewById(R.id.vp);
ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter();
viewPager.setAdapter(viewPagerAdapter);
}
}
- ViewPagerAdapter.java
package com.example.myviewpager2;
import android.graphics.drawable.Drawable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
public class ViewPagerAdapter extends RecyclerView.Adapter<ViewPagerAdapter.ViewPagerViewHolder> {
private List<String> titles = new ArrayList<>();
private List<Integer> colors = new ArrayList<>();
public ViewPagerAdapter(){
titles.add("haha");
titles.add("xixi");
titles.add("hehe");
titles.add("enen");
colors.add(R.color.white);
colors.add(R.color.purple_200);
colors.add(R.color.purple_500);
colors.add(R.color.purple_700);
}
// 子布局必须是march_parent，否则这个函数不会执行
@NonNull
@Override
public ViewPagerViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_pager, parent, false)
return new ViewPagerViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull ViewPagerViewHolder holder, int position) {
holder.mTv.setText(titles.get(position));
// 填进去的是资源id
holder.mContainer.setBackgroundResource(colors.get(position));
}
@Override
public int getItemCount() {
return 4;
}
class ViewPagerViewHolder extends RecyclerView.ViewHolder{
private TextView mTv;
private RelativeLayout mContainer;
public ViewPagerViewHolder(@NonNull View itemView) {
super(itemView);
mContainer = itemView.findViewById(R.id.container);
mTv = itemView.findViewById(R.id.tvTitle);
}
}
}
Menu
- 在res中添加menu文件夹，新建menu.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="@+id/add_item"
android:title="Add"/>
<item
android:id="@+id/remove_item"
android:title="Remove"/>
</menu>
- 在Activity中重写onCreateOptionsMenu()，快捷键ctrl+o
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu, menu);
// 返回true表示允许创建的菜单显示出来
return true;
}
- 重写onOptionsItemSelected()实现菜单按钮点击
@Override
public boolean onOptionsItemSelected(@NonNull MenuItem item) {
switch (item.getItemId()){
case R.id.add_item:
Toast.makeText(this, "add", Toast.LENGTH_SHORT).show();
break;
case R.id.remove_item:
Toast.makeText(this, "remove", Toast.LENGTH_SHORT).show();
// 等同于按下Back键
finish();
break;
default:
}
return true;
}
基础控件(ListView,RecyclerView,单位和尺寸,ViewPager,ViewPager2)的更多相关文章
- Android基础控件ListView基础操作
1.简介 基于Android基础控件ListView和自定义BaseAdapter适配器情况下,对ListView的数据删除和添加操作: public boolean add(E e) {//添加数据 ...
- Android基础控件ListView和自定义BaseAdapter适配器
1.简介 ListView用于列表显示,相当于OC中的TableView,和适配器一块使用,相关属性: footerDividersEnabled:是否在footerView(表尾)前绘制一个分隔条, ...
- [iOS基础控件 - 5.5] 代理设计模式 (基于”APP列表"练习)
A.概述 在"[iOS基础控件 - 4.4] APP列表 进一步封装,初见MVC模式”上进一步改进,给“下载”按钮加上效果.功能 1.按钮点击后,显示为“已下载”,并且不 ...
- Delphi一共封装（超类化）了8种Windows基础控件和17种复杂控件
超类化源码: procedure TWinControl.CreateSubClass(var Params: TCreateParams; ControlClassName: PChar); con ...
- React Native环境搭建以及几个基础控件的使用
之前写了几篇博客,但是没有从最基础的开始写,现在想了想感觉不太合适,所以现在把基础的一些东西给补上,也算是我从零开始学习RN的经验吧! 一.环境搭建 首先声明一下,本人现在用的编辑器是SublimeT ...
- [Android Pro] android控件ListView顶部或者底部也显示分割线
reference to : http://blog.csdn.net/lovexieyuan520/article/details/50846569 在默认的Android控件ListView在 ...
- Cocos2d-JS项目之二：studio基础控件的使用
在studio里把几个基础控件往场景文件一拖,然后导出json格式的资源文件 逻辑代码如下: var HelloWorldLayer = cc.Layer.extend({ sprite:null, ...
- [iOS基础控件 - 6.9.1] 聊天界面Demo 代码
框架: 所有代码文件: Model: // // Message.h // QQChatDemo // // Created by hellovoidworld on 14/12/8. // ...
- Cocos2d-JS studio基础控件的使用
在studio里把几个基础控件往场景文件一拖,然后导出json格式的资源文件 逻辑代码如下: 1 var HelloWorldLayer = cc.Layer.extend({ 2 sprite:nu ...
- Python Tkinter基础控件入门实例
分享一个Python Tkinter基础控件用法的入门例子,包括窗口的显示.显示内置图片.弹出窗口.菜单等. 例子,Python Tkinter基础控件的用法 # -*- coding: utf-8 ...
随机推荐
- CCF A类会议 —— AAAI2022 论文审稿模板
======================================================= 前段时间为实验室负责审理AAAI 2022的会议稿件,感觉这个审稿模板还是不错的,这里保 ...
- 模拟实现FutureTask
1.背景 面试官问,,假设让你编写一个FutureTask,你的思路是..... 2.代码 2.1.GuardedObject对象 package com.common; /** * @author ...
- 使用 Apache SeaTunnel 实现 Kafka Source 解析复杂Json 案例
版本说明: SeaTunnel:apache-seatunnel-2.3.2-SNAPHOT 引擎说明: Flink:1.16.2 Zeta:官方自带 前言 近些时间,我们正好接手一个数据集成项目,数 ...
- 《最新出炉》系列小成篇-Python+Playwright自动化测试-66 - 等待元素至指定状态(出现、移除、显示和隐藏)
1.简介 在我们日常工作中进行UI自动化测试时,保证测试的稳定性至关重要.其中一个关键方面是正确地定位和操作网页中的元素.在网页中,元素可能处于不同的状态,有些可能在页面加载完成之前不在DOM中,需要 ...
- 【模板】树的直径(dfs & dp)
树的直径 给定n个点 n-1条边 和每条边的val 输出直径的大小和 直径上的点的序号 input: 8 1 2 2 1 3 1 1 5 10 2 4 3 4 6 4 3 7 5 7 8 2 outp ...
- [学习笔记] hash & kmp & Trie树 - 字符串
Hash Oulipo 没啥好说的,进制hash板子. #include<bits/stdc++.h> using namespace std; #define ull unsigned ...
- sqlserver 索引优化 CPU占用过高 执行分析 服务器检查[转]
SELECT TOP 10 [Total Cost] = ROUND(avg_total_user_cost * avg_user_impact * (user_seeks + user_scans) ...
- 使用Web Component定义自己的专属网页组件
什么是Web Component Web Component是一套Web浏览器的技术和规范,能够让开发者定制自己的HTML元素 来自MDN的描述: Web Component 是一套不同的技术,允许你 ...
- docker启动一个不停止的centos系统容器
启动的镜像后加上/usr/sbin/init ,前提是镜像中没有设置entrypoint
- Ansible-playbook 应用梳理
前面已经介绍过Ansible的安装配置及常见模块的使用 --<Linux下使用Ansible处理批量操作> Palybook简介 palybook是由一个或多个paly组成的列表,play ...