代码如下,内有详细注释
主函数
package com.example.homework;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ResolveInfo;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private ListView mListView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mListView = findViewById(R.id.list_text);
//LayoutInflater layoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
List<ResolveInfo> infos = getAppInfos();
mListView.setAdapter(new AppListAdapter(getAppInfos()));
}
//拿到系统应用所有信息
private List<ResolveInfo> getAppInfos(){
Intent intent = new Intent(Intent.ACTION_MAIN,null);
intent.addCategory(Intent.CATEGORY_LAUNCHER);
return getPackageManager().queryIntentActivities(intent, 0);
}
//配置ListView的适配器
private class AppListAdapter extends BaseAdapter{
List<ResolveInfo> mAppNames;
public AppListAdapter(List<ResolveInfo> AppNames){
mAppNames = AppNames;
}
@Override
public int getCount() {
return mAppNames.size();
}
@Override
public Object getItem(int position) {
return mAppNames.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
LayoutInflater layoutInflater = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
//判断是否为空,为空的话
if(convertView == null){
viewHolder = new ViewHolder();
convertView = layoutInflater.inflate(R.layout.item_item, null);
// 获取控件
viewHolder.nameTextView = convertView.findViewById(R.id.title_text_view);
viewHolder.avatarImageView = convertView.findViewById(R.id.icon_image_view);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
// 和数据之间进行绑定
//获取应用名字
viewHolder.nameTextView.setText(mAppNames.get(position).activityInfo.loadLabel(getPackageManager()));
//获取应用图片
viewHolder.avatarImageView.setImageDrawable(mAppNames.get(position).activityInfo.loadIcon(getPackageManager()));
//对系统应用设置点击事件
convertView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
ResolveInfo info = mAppNames.get(position);
//该应用的包名
String pkg = info.activityInfo.packageName;
//应用的主activity类
String cls = info.activityInfo.name;
ComponentName componet = new ComponentName(pkg, cls);
Intent intent = new Intent();
intent.setComponent(componet);
startActivity(intent);
}
});
return convertView;
}
class ViewHolder {
ImageView avatarImageView;
TextView nameTextView;
}
}
}
主函数XML
<?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:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<ImageView
android:layout_width="50dp"
android:layout_height="50dp"
android:src="@mipmap/sousuo" />
<EditText
android:id="@+id/edtext_sosuo"
android:layout_width="match_parent"
android:layout_height="50dp"
android:hint="请输入~~~~~~"
/>
</LinearLayout>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/list_text">
</ListView>
</LinearLayout>
配置ListView的DEMO,图片自己可以换
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<ImageView
android:id="@+id/icon_image_view"
android:layout_width="60dp"
android:layout_height="60dp"
android:src="@mipmap/ic_launcher"/>
<TextView
android:id="@+id/title_text_view"
android:layout_width="match_parent"
android:layout_height="60dp"
android:text="@string/app_name"
android:minHeight="30dp"
android:layout_centerVertical="true"
android:gravity="left|center"
android:textColor="#494949"
android:singleLine="true"
android:layout_marginLeft="16dp"
android:layout_toRightOf="@+id/icon_image_view"
android:textSize="18sp"/>
</LinearLayout>