安卓开发|安卓入门学习笔记(GridView实现app勾选页面)


安卓studio开发环境的搭建推荐这个博客:https://blog.csdn.net/JerkSpan/article/details/85811265
花了两三天将java基础过了一遍,推荐廖雪峰老师的java基础教程:https://www.liaoxuefeng.com/wiki/1252599548343744
然后花了大概一周将安卓基础过了一遍,看得是“安卓开发入门教程:7天玩转安卓开发 ”:http://c.biancheng.net/android/
入门了接下来就需要自己实操下,想实现一个类似桌面launcher的界面,可以点击加号的图标添加app图标到这个界面。这里分享的是点击加号后进入app勾选界面的实现。效果如下:
安卓开发|安卓入门学习笔记(GridView实现app勾选页面)
文章图片

点击图标勾选,再点击勾选图标变灰。
【安卓开发|安卓入门学习笔记(GridView实现app勾选页面)】思路:这种布局毫无疑问是用Gridview控件来实现了,我想把原来的标题栏去掉,自己定制上图中的标题栏(有返回按钮,有提交按钮,还可以显示勾选了多少app),实现也很简单,
第一步:修改AndroidManifest.xml将原来的标题栏隐藏掉,并设置界面是横屏显示:


将界面用RelativeLayout布局分成上下两部分,上一部分放自己定制的标题栏,下部分放Gridview控件。布局XML(activity_apps_grid.xml)如下:

Gridview每行显示5个Item。
第二步:界面整体布局配置好后,需要配置下GridView里面每个Item的内容了。每个Item需要显示APP的图标,包名,还要在右上角显示勾选的图标。所以一个Item里面包含三个控件,grid_item.xml内容如下:

上两步做完,整体布局就配置好了。
第三步:就是activity代码的实现了,我是用SimpleAdapter作为GridView控件的适配器,用法还是比较简单的,代码的注释也比较清楚了。代码如下:
/************************************************* *作者:范陈新 *邮箱:531266381@qq.com *日期:2020-03-05 *版本:Ver-01 **************************************************/ package com.example.android_learn; import android.content.Intent; import android.os.Bundle; import androidx.appcompat.app.AppCompatActivity; import android.view.View; import android.widget.AdapterView; import android.widget.GridView; import android.widget.ImageButton; import android.widget.SimpleAdapter; import android.widget.ImageView; import android.widget.TextView; import android.content.pm.ApplicationInfo; import android.content.pm.PackageInfo; import android.content.pm.PackageManager; import android.graphics.drawable.Drawable; import java.io.InputStream; import java.util.ArrayList; import java.util.HashMap; import java.util.List; public class AppsGridActivity extends AppCompatActivity { private SimpleAdapter gridItemAdapter; private int appCheckCnt = 0; private ArrayList listItemsFile = new ArrayList(); //用来保存配置文件的每个app的信息及选中状态 private ArrayList listItemsCur = new ArrayList(); //用来保存当前更新的每个app的信息及选中状态@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_apps_grid); initGridView(); // 返回按钮的响应 ImageButton backButton = (ImageButton)findViewById(R.id.griview_TitleBar_BackButton); backButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { //将ListItemsSave的选中状态拷贝给listItems for(int i = 0; i < listItemsFile.size(); i++) { HashMap item = (HashMap)listItemsFile.get(i); Boolean pkg_check = (Boolean) item.get("ItemCheck"); listItemsCur.get(i).replace("ItemCheck", pkg_check); }Intent intent = new Intent(); intent.putExtra("return", "返回"); setResult(0, intent); finish(); } }); // 点击返回文本 TextView backText = (TextView)findViewById(R.id.griview_TitleBar_BackText); backText.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { //将ListItemsSave的选中状态拷贝给listItems for(int i = 0; i < listItemsFile.size(); i++) { HashMap item = (HashMap)listItemsFile.get(i); Boolean pkg_check = (Boolean) item.get("ItemCheck"); listItemsCur.get(i).replace("ItemCheck", pkg_check); } Intent intent = new Intent(); intent.putExtra("return", "返回"); setResult(0, intent); finish(); } }); //点击提交 TextView commitText = (TextView)findViewById(R.id.griview_TitleBar_Commit); commitText.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { for(int i = 0; i < listItemsCur.size(); i++) { HashMap item = (HashMap)listItemsCur.get(i); String pkg_name = (String) item.get("ItemTitle"); Boolean pkg_check = (Boolean) item.get("ItemCheck"); setAppCheckState(pkg_name, pkg_check); listItemsFile.get(i).replace("ItemCheck",pkg_check ); }Intent intent = new Intent(); intent.putExtra("return", "提交"); setResult(0, intent); finish(); } }); }private void initGridView() { //生成动态数组,并且转入数据 PackageManager pm = getPackageManager(); List installedPackages = pm.getInstalledPackages(0); // 获取所以已安装的包 String selfPkgName = getApplicationContext().getPackageName(); for (PackageInfo packageInfo : installedPackages) { String packageName = packageInfo.packageName; // 包名 ApplicationInfo applicationInfo = packageInfo.applicationInfo; // 应用信息 String name = applicationInfo.loadLabel(pm).toString(); // 应用名称 Drawable icon = applicationInfo.loadIcon(pm); // 应用图标 Boolean check = false; System.out.println("@@@@@@@@name: "+name); System.out.println("########packageName:"+packageName); // 状态机,通过01状态来表示是否具备某些属性和功能 int flags = applicationInfo.flags; // 获取应用标记 if ((flags & ApplicationInfo.FLAG_EXTERNAL_STORAGE) == ApplicationInfo.FLAG_EXTERNAL_STORAGE) { //安装在sdcard } else { //安装在手机 }if ((flags & ApplicationInfo.FLAG_SYSTEM) == ApplicationInfo.FLAG_SYSTEM) { //系统应用 System.out.println(name + "--->" + "系统应用"); } else { //用户应用 System.out.println(name + "--->" + "用户应用"); }if((name.startsWith("com.", 0) == false) && !selfPkgName.equals(packageName)) { //过滤掉com.xx开头的包和本身 HashMap map = new HashMap(); check = getAppCheckState(name); if(check == true) { appCheckCnt++; } map.put("ItemTitle", name); //包简称 map.put("ItemPkgName", packageName); map.put("ItemImage", icon); //包的图标 map.put("ItemCheck", check); //是否被选中 listItemsCur.add(map); } }listItemsFile = (ArrayList)listItemsCur.clone(); //复制//修改标题栏内容 TextView titleContent = (TextView)findViewById(R.id.griview_TitleBar_Title); titleContent.setText("添加应用到桌面("+ appCheckCnt + "/" + listItemsCur.size() + ")"); //生成适配器的ImageItem <====> 动态数组的元素,两者一一对应 gridItemAdapter = new SimpleAdapter(this, listItemsCur,//数据来源 R.layout.grid_item, //grid_item的XML实现 //动态数组与ImageItem对应的子项 new String[] {"ItemImage","ItemTitle","ItemCheck"}, //ImageItem的XML文件里面的一个ImageView,两个TextView ID new int[] {R.id.AppIcon, R.id.AppName, R.id.AppCheck}); gridItemAdapter.setViewBinder(new SimpleAdapter.ViewBinder() { @Override public boolean setViewValue(View view, Object data, String s) { if(view instanceof ImageView && data instanceof Drawable){ //设置APP图标ImageView数据源 ImageView iv = (ImageView)view; iv.setImageDrawable((Drawable)data); return true; } else if(view instanceof ImageView && data instanceof Boolean){ //设置是否勾选ImageView数据源 ImageView iv = (ImageView)view; if((Boolean)data =https://www.it610.com/article/= true) { iv.setImageResource(R.mipmap.item_check); } else { iv.setImageResource(R.mipmap.item_uncheck); } return true; } else{ return false; } } }); final GridView gridView =(GridView)findViewById(R.id.gridView_showApps); //添加并且显示 gridView.setAdapter(gridItemAdapter); //添加消息处理 gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView parent, View view, int position, long id) { HashMap item = (HashMap) gridItemAdapter.getItem(position); String packageName = (String)item.get("ItemPkgName"); System.out.println(packageName + " be clicked!"); int firstVisiblePos = gridView.getFirstVisiblePosition(); int lastVisiblePos = gridView.getLastVisiblePosition(); if(position >= firstVisiblePos && position <= lastVisiblePos) { View itemView = gridView.getChildAt(position - firstVisiblePos); ImageView itemCheck = (ImageView) itemView.findViewById(R.id.AppCheck); //点击勾选或取消勾选 if ((Boolean) item.get("ItemCheck") == false) { ((HashMap) gridItemAdapter.getItem(position)).replace("ItemCheck", true); itemCheck.setImageResource(R.mipmap.item_check); appCheckCnt++; TextView titleContent = (TextView)findViewById(R.id.griview_TitleBar_Title); titleContent.setText("添加应用到桌面("+ appCheckCnt + "/" + listItemsCur.size() + ")"); } else { ((HashMap) gridItemAdapter.getItem(position)).replace("ItemCheck", false); itemCheck.setImageResource(R.mipmap.item_uncheck); appCheckCnt--; TextView titleContent = (TextView)findViewById(R.id.griview_TitleBar_Title); titleContent.setText("添加应用到桌面("+ appCheckCnt + "/" + listItemsCur.size() + ")"); } } } }); }//从代码包asserts目录下拷贝配置文件到/data/data/安装包名/ private void cpConfigFile() { try { InputStream in = getApplicationContext().getAssets().open("app_select.properties"); String path = "/data/data/" + getApplicationContext().getPackageName(); AppsConfigSetting.cpConfigFile(in, path); } catch (Exception e) { e.printStackTrace(); } }//从配置文件获取选中状态 private Boolean getAppCheckState(String pkg_name) { return AppsConfigSetting.getAppCheckState(pkg_name); }//保存状态到配置文件 private void setAppCheckState(String pkg_name, Boolean state) { AppsConfigSetting.setAppCheckState(pkg_name, state); } }

刚入门安卓开发,特此学习记录下,希望也对入门安卓开发的同学有帮助。



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