1.DatePicker和DatePickerDialog的基本使用方法：

main.xml:

MainActivity.xml:

package mars.dateandtime;

import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.Dialog;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.DatePicker;

public class MainActivity extends Activity {
/** Called when the activity is first created. */
private Button showDatePickerButton = null;
//该常量用于标识DatePickerDialog
private static final int DATE_PICKER_ID = 1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
showDatePickerButton = (Button) findViewById(R.id.showDatePickerButton);
showDatePickerButton.setOnClickListener(new ButtonListener());
}

private class ButtonListener implements OnClickListener {

    @Override  
    public void onClick(View v) {  
        //此方法用于显示DatePickerDialog  
        showDialog(DATE\_PICKER\_ID);  
    }

}  
//监听器，用户监听用户点下DatePikerDialog的set按钮时，所设置的年月日  
DatePickerDialog.OnDateSetListener onDateSetListener = new DatePickerDialog.OnDateSetListener() {

    @Override  
    public void onDateSet(DatePicker view, int year, int monthOfYear,  
            int dayOfMonth) {  
        System.out.println(year + "-" + monthOfYear + "-" + dayOfMonth);  
    }  
};

@Override  
protected Dialog onCreateDialog(int id) {  
    switch (id) {  
    case DATE\_PICKER\_ID:  
        return new DatePickerDialog(this, onDateSetListener, 2010, 11, 25);  
    }  
    return null;  
}

}

注意：月份是从0开始的。

2.AutoCompleteTextView的基本使用方法：

main.xml:

list_item.xml(用于显示下拉菜单的显示效果)

MainActivity.java:

package mars.autocomplete;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;

public class MainActivity extends Activity {
/** Called when the activity is first created. */
AutoCompleteTextView autoCompleteTextView = null;
static final String[] COUNTRIES = new String[] {
"Afghanistan", "Albania", "Algeria", "American Samoa", "Andorra",
"Angola", "Anguilla", "Antarctica", "Antigua and Barbuda", "Argentina",
"Armenia", "Aruba", "Australia", "Austria", "Azerbaijan",
"Bahrain", "Bangladesh", "Barbados", "Belarus", "Belgium",
"Belize", "Benin", "Bermuda", "Bhutan", "Bolivia",
"Bosnia and Herzegovina", "Botswana", "Bouvet Island", "Brazil", "British Indian Ocean Territory",
"British Virgin Islands", "Brunei", "Bulgaria", "Burkina Faso", "Burundi",
"Cote d'Ivoire", "Cambodia", "Cameroon", "Canada", "Cape Verde",
"Cayman Islands", "Central African Republic", "Chad", "Chile", "China",
"Christmas Island", "Cocos (Keeling) Islands", "Colombia", "Comoros", "Congo",
"Cook Islands", "Costa Rica", "Croatia", "Cuba", "Cyprus", "Czech Republic",
"Democratic Republic of the Congo", "Denmark", "Djibouti", "Dominica", "Dominican Republic",
"East Timor", "Ecuador", "Egypt", "El Salvador", "Equatorial Guinea", "Eritrea",
"Estonia", "Ethiopia", "Faeroe Islands", "Falkland Islands", "Fiji", "Finland",
"Former Yugoslav Republic of Macedonia", "France", "French Guiana", "French Polynesia",
"French Southern Territories", "Gabon", "Georgia", "Germany", "Ghana", "Gibraltar",
"Greece", "Greenland", "Grenada", "Guadeloupe", "Guam", "Guatemala", "Guinea", "Guinea-Bissau",
"Guyana", "Haiti", "Heard Island and McDonald Islands", "Honduras", "Hong Kong", "Hungary",
"Iceland", "India", "Indonesia", "Iran", "Iraq", "Ireland", "Israel", "Italy", "Jamaica",
"Japan", "Jordan", "Kazakhstan", "Kenya", "Kiribati", "Kuwait", "Kyrgyzstan", "Laos",
"Latvia", "Lebanon", "Lesotho", "Liberia", "Libya", "Liechtenstein", "Lithuania", "Luxembourg",
"Macau", "Madagascar", "Malawi", "Malaysia", "Maldives", "Mali", "Malta", "Marshall Islands",
"Martinique", "Mauritania", "Mauritius", "Mayotte", "Mexico", "Micronesia", "Moldova",
"Monaco", "Mongolia", "Montserrat", "Morocco", "Mozambique", "Myanmar", "Namibia",
"Nauru", "Nepal", "Netherlands", "Netherlands Antilles", "New Caledonia", "New Zealand",
"Nicaragua", "Niger", "Nigeria", "Niue", "Norfolk Island", "North Korea", "Northern Marianas",
"Norway", "Oman", "Pakistan", "Palau", "Panama", "Papua New Guinea", "Paraguay", "Peru",
"Philippines", "Pitcairn Islands", "Poland", "Portugal", "Puerto Rico", "Qatar",
"Reunion", "Romania", "Russia", "Rwanda", "Sqo Tome and Principe", "Saint Helena",
"Saint Kitts and Nevis", "Saint Lucia", "Saint Pierre and Miquelon",
"Saint Vincent and the Grenadines", "Samoa", "San Marino", "Saudi Arabia", "Senegal",
"Seychelles", "Sierra Leone", "Singapore", "Slovakia", "Slovenia", "Solomon Islands",
"Somalia", "South Africa", "South Georgia and the South Sandwich Islands", "South Korea",
"Spain", "Sri Lanka", "Sudan", "Suriname", "Svalbard and Jan Mayen", "Swaziland", "Sweden",
"Switzerland", "Syria", "Taiwan", "Tajikistan", "Tanzania", "Thailand", "The Bahamas",
"The Gambia", "Togo", "Tokelau", "Tonga", "Trinidad and Tobago", "Tunisia", "Turkey",
"Turkmenistan", "Turks and Caicos Islands", "Tuvalu", "Virgin Islands", "Uganda",
"Ukraine", "United Arab Emirates", "United Kingdom",
"United States", "United States Minor Outlying Islands", "Uruguay", "Uzbekistan",
"Vanuatu", "Vatican City", "Venezuela", "Vietnam", "Wallis and Futuna", "Western Sahara",
"Yemen", "Yugoslavia", "Zambia", "Zimbabwe"
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//通过ID得到AutoCompleteTextView对象
autoCompleteTextView = (AutoCompleteTextView)findViewById(R.id.autocomplete);
//创建一个list，为ArrayAdapter提供数据
List list = new ArrayList();
list.add("测试测试");
list.add("测试test");
//创建一个ArrayAdapter对象
ArrayAdapter arrayAdapter = new ArrayAdapter(this,R.layout.list_item,COUNTRIES); 最后一个参数可以是一个list也可以是个字符数组
//将ArrayAdapter设置给AutoCompleteTextView对象
autoCompleteTextView.setAdapter(arrayAdapter);

}  

}

显示如下: