第一行代码Android学习（三）

第一行代码Android学习：第三部分主要涉及到简单的自定义控件和优化后ListView的写法

1.activity_main.xml <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" > <com.example.dyhdm_02_00uicustomviews.TitleLayout android:id="@+id/tl_title" android:layout_width="match_parent" android:layout_height="wrap_content" > </com.example.dyhdm_02_00uicustomviews.TitleLayout> <ListView android:id="@+id/lv_test" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_below="@id/tl_title" > </ListView> </RelativeLayout> 2.item_test.xml <?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" > <TextView android:id="@+id/tv1" android:layout_marginRight="50dp" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <TextView android:id="@+id/tv2" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout> 3.title.xml <?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" > <Button android:id="@+id/bt_back" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="返回" > </Button> <TextView android:id="@+id/tv_title" android:layout_width="0dp" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:textSize="20dp" android:text="标题" /> <Button android:id="@+id/bt_edit" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="编辑" > </Button> </LinearLayout> 4.MainActivity.java package com.example.dyhdm_02_00uicustomviews; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.Window; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ListView; import android.widget.Toast; public class MainActivity extends Activity { private ListView lv_test; private TestAdapter adapter; private List<Map<String, String>> list = new ArrayList<Map<String, String>>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestWindowFeature(Window.FEATURE_NO_TITLE); setContentView(R.layout.activity_main); for (int i = 0; i < 5; i++) { Map<String, String> map = new HashMap<String, String>(); map.put("arg1", "111"); map.put("arg2", "222"); list.add(map); } lv_test = (ListView) findViewById(R.id.lv_test); adapter = new TestAdapter(this, R.layout.item_test, list); lv_test.setAdapter(adapter); lv_test.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { Toast.makeText(MainActivity.this, position+"", Toast.LENGTH_SHORT).show(); } }); } } 5.TestAdapter.java /* * @Title: TestAdapter.java * @Description: TODO * @author: 张志安 * @data: 2016-8-15 下午2:00:49 * */ package com.example.dyhdm_02_00uicustomviews; import java.util.ArrayList; import java.util.List; import java.util.Map; import android.content.Context; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.TextView; /** * TODO 测试用的Adapter * * @author 张志安 * @date: 2016-8-15 下午2:00:49 */ public class TestAdapter extends ArrayAdapter { private int resourceId; private List<Map<String, String>> list = new ArrayList<Map<String, String>>(); /** * <默认构造函数> */ public TestAdapter(Context context, int textViewResourceId, List objects) { super(context, textViewResourceId, objects); resourceId = textViewResourceId; list = objects; } /** * 重载方法 */ @Override public View getView(int position, View convertView, ViewGroup parent) { View view; ViewHold viewHold; if (convertView == null) { view = LayoutInflater.from(getContext()).inflate(resourceId, null); viewHold = new ViewHold(); viewHold.tv1 = (TextView) view.findViewById(R.id.tv1); viewHold.tv2 = (TextView) view.findViewById(R.id.tv2); view.setTag(viewHold); } else { view = convertView; viewHold = (ViewHold) view.getTag(); } viewHold.tv1.setText(list.get(position).get("arg1")); viewHold.tv2.setText(list.get(position).get("arg2")); return view; } class ViewHold { TextView tv1; TextView tv2; } } 6.TitleLayout.java /* * @Title: TitleLayout.java * @Description: TODO * @author: 张志安 * @data: 2016-8-15 上午10:48:00 * */ package com.example.dyhdm_02_00uicustomviews; import android.app.Activity; import android.content.Context; import android.util.AttributeSet; import android.view.LayoutInflater; import android.view.View; import android.widget.Button; import android.widget.LinearLayout; import android.widget.Toast; /** * TODO 自定义的控件 * @author 张志安 * @data: 2016-8-15 上午10:48:00 */ public class TitleLayout extends LinearLayout { /** * <默认构造函数> */ public TitleLayout(Context context, AttributeSet attrs) { super(context, attrs); LayoutInflater.from(context).inflate(R.layout.title, this); Button bt_back = (Button) findViewById(R.id.bt_back); Button bt_edit = (Button) findViewById(R.id.bt_edit); bt_back.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { ((Activity) getContext()).finish(); } }); bt_edit.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { Toast.makeText(getContext(), "Edit", Toast.LENGTH_SHORT).show(); } }); } }

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