5.2 Android Basic QuickStart Widgets&Other View Date Picker
Date Picker
日期选择控件，允许你选择月，日，年。
在本教程中，将创建DatePickerDialog 对话框。TextView将更新显示选中的日期。
- 新建项目 HelloDatePicker。
-
打开res/layout/main.xml文件修改代码如下：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
>
<TextView android:id="@+id/dateDisplay"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text=""
/>
<Button android:id="@+id/pickDate"
android:layout_width = "wrap_content"
android:layout_height="wrap_content"
android:text = "Change the date"/>
</LinearLayout>
3. 打开 HelloDatePicker.java增加下面的成员变量到类:
private TextView mDateDisplay;
private Button mPickDate;
private int mYear;
private int mMonth;
private int mDay;
4. 增加下面的代码到onCreate()方法:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//capture our ivew elements
mDateDisplay = (TextView)findViewById(R.id.dateDisplay);
mPickDate = (Button)findViewById(R.id.pickDate);
// add a click listener to the button
mPickDate.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
showDialog(DATE_DIALOG_ID);
}
});
// GET THE CURENT DATE
final Calendar c = Calendar.getInstance();
mYear = c.get(Calendar.YEAR);
mMonth = c.get(Calendar.MONTH);
mDay = c.get(Calendar.DAY_OF_MONTH);
//display the current date (this method is below)
updateDisplay();
}
5. 增加updateDisplay()方法:
//updates the date in the TextView
private void updateDisplay(){
mDateDisplay.setText(
new StringBuilder().append(mMonth+1).append("-")
.append(mDay).append("-")
.append(mYear).append(" ")
);
}
6. 初始化一个DatePickerDialog.OnDateSetLintener 成员。
private DatePickerDialog.OnDateSetListener mDateSetListener=
new DatePickerDialog.OnDateSetListener(){
public void onDateSet(DatePicker view, int year,
int monthOfYear,int dayOfMonth){
mYear = year;
mMonth = monthOfYear;
mDay = dayOfMonth;
updateDisplay();
}
};
7. 重载OnCreateDialog方法：
@Override
protected Dialog onCreateDialog(int id) {
switch(id){
case DATE_DIALOG_ID:
return new DatePickerDialog(this,
mDateSetListener,
mYear,mMonth,mDay
);
}
return null;
}
8. 运行应用程序
author: im@xingquan.org
