Android 自动完成文本框

一、自动完成文本框的定义:
自动完成文本框是在输入框中根据输入信息提示与其相关信息的UI控件。
二、如何使用自动完成文本框：
【ListView】
1.系统提供的Adapter填充数据
2.自定义Adapter填充数据
【AutoCompleteTextView】
1.系统提供的Adapter填充数据
2.自定义Adapter填充数据
三、使用系统提供的Adapter填充数据：
1）编写布局

2）准备数据

	protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_auto_complete_text_view);
		// 准备数据
        String[] books = new String[]{“rollen”,"rollenholt", "rollenren", "roll"};
    }

3）关联数据

	protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_auto_complete_text_view);
		// 准备数据
        String[] books = new String[]{“rollen”,"rollenholt", "rollenren", "roll"};
		// 关联数据
        ArrayAdapter av = new
                ArrayAdapter(this, android.R.layout.simple_dropdown_item_1line, books);
        AutoCompleteTextView auto = findViewById(R.id.auto_complete_textview);
        auto.setAdapter(av);
    }

4）查看效果

四、使用自定义Adapter填充数据
1）编写布局-Activity

2）编写布局-提示项列表

3）准备数据-Adapter

public class AutoCompleteTextViewActivity extends AppCompatActivity {
    private ArrayList data = new ArrayList<>();
	private String[] emails = {"@qq.com", "@163.com", "@sina.com", "@gmail.com"}
	protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_auto_complete_text_view);
	}
	…
 }

4）关联数据

class SearchEmailAdapter extends BaseAdapter {
		 public int getCount() {
            return data.size();
        }
		 public Object getItem(int position) {
            return data.get(position);
        }
	    public long getItemId(int position) {
            return position;
        }
		 class ViewHolder {
            TextView tvEmail;
        }
}

5）关联数据-Adapter

 public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder holder = null;
            if (convertView == null) {
                holder = new ViewHolder();
                convertView = LayoutInflater.from(AutoCompleteTextViewActivity.this)
                        .inflate(R.layout.email_search_layout, null);
                holder.tvEmail = convertView.findViewById(R.id.tv_email_name);
                convertView.setTag(holder);
            } else {
                holder = (ViewHolder) convertView.getTag();
            }
            holder.tvEmail.setText(data.get(position));
            return convertView;
 }
 class SearchEmailAdapter extends BaseAdapter implements Filterable {
	   public Filter getFilter() {
            Filter filter = new Filter() {
		      protected FilterResults performFiltering(CharSequence constraint) {
                    FilterResults results = new FilterResults();
                    ArrayList newData = new ArrayList<>();
                    if (constraint != null && !constraint.toString().contains("@")) {
                        for (String data : emails) {
                            newData.add(constraint + data);
                        }
                    }
                    results.values = newData;
                    results.count = newData.size();
                    return results;
                }
		      protected void publishResults(CharSequence constraint, FilterResults results) {
                    data = (ArrayList) results.values;
                    notifyDataSetChanged();
                }![在这里插入图片描述](https://img-blog.csdnimg.cn/20190215091225522.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80Mzc3ODcyMA==,size_16,color_FFFFFF,t_70)
            };
            return filter;
        }
}

6）关联数据-Activity

public class AutoCompleteTextViewActivity extends AppCompatActivity {
    private ArrayList data = new ArrayList<>();
	private String[] emails = {"@qq.com", "@163.com", "@sina.com", "@gmail.com"}
	protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_auto_complete_text_view);
        AutoCompleteTextView auto = findViewById(R.id.auto_complete_textview);
        auto.setAdapter(new SearchEmailAdapter());
	}
	…
 }

7）运行效果

五、自动完成文本框的属性方法：
clearListSelection() 清除所有的提示列表项
getAdapter() 取得数据集
setAdapter() 设置数据集
setOnClickListener() 设置单击事件
setOnItemClickListener() 在选项上设置单击事件
setOnItemSelectedListener() 选项选中时的事件