在自定义对话框中使用的DatePicker [英] Using DatePicker on custom dialog
问题描述
好吧,这就是我的code.I想从一个自定义对话框一个datepicker取值。当我尝试初始化DP(的DatePicker)我得到NullPointerException错误,我不能把值从的DatePicker变量。 :/任何人都知道是怎么回事? (我有1布局,主要(R.layout.notifications)和对话框布局(R.layout.notifications_dialog)的日期选择器是在notifications_dialog布局。
公共类通知扩展活动{静态最终诠释CUSTOM_DIALOG_ID = 0;
通知的EditText,频率;
按钮保存,取消;
INT年,月,日;
DatePicker的DP;@覆盖
保护无效的onCreate(捆绑savedInstanceState){
super.onCreate(savedInstanceState);
的setContentView(R.layout.notifications);
OK按钮=(按钮)findViewById(R.id.ok);
DP =(的DatePicker)findViewById(R.id.notdate);
ok.setOnClickListener(新OnClickListener(){
公共无效的onClick(查看ovuinfo){
的ShowDialog(CUSTOM_DIALOG_ID);
}
});
}@覆盖
保护对话框onCreateDialog(INT ID){
对话的对话= NULL ;;
开关(ID){
案例CUSTOM_DIALOG_ID:
对话框=新的对话框(Notifications.this); dialog.setContentView(R.layout.notifications_dialog);
dialog.setTitle(添加通知); 通知=(EditText上)dialog.findViewById(R.id.notification);
频率=(EditText上)dialog.findViewById(R.id.freq);
保存=(按钮)dialog.findViewById(R.id.add);
取消=(按钮)dialog.findViewById(R.id.canc);
DP =(的DatePicker)findViewById(R.id.notdate); 最后的日历CAL = Calendar.getInstance();
年整型= cal.get(Calendar.YEAR);
INT monthOfYear = cal.get(的Calendar.MONTH);
INT请将dayOfMonth = cal.get(Calendar.DAY_OF_MONTH); //这里是问题!
dp.init(年,monthOfYear,请将dayOfMonth,新OnDateChangedListener(){
@覆盖
公共无效onDateChanged(查看的DatePicker,年整型,诠释monthOfYear,诠释请将dayOfMonth){
年=年;
月= monthOfYear;
天=请将dayOfMonth;
}
}); Save.setOnClickListener(SaveOnClickListener);
Cancel.setOnClickListener(CancelOnClickListener);
打破;
}
返回对话框;
} 私人Button.OnClickListener SaveOnClickListener =新Button.OnClickListener(){
@覆盖
公共无效的onClick(查看为arg0){
。字符串不等于Notification.getText()的toString();
。字符串FRE = Freq.getText()的toString(); 吐司面包= Toast.makeText(getApplicationContext(),而不是+:+ FRE +:+日+ - +月+ - +年,Toast.LENGTH_SHORT);
toast.show();
}
}; 私人Button.OnClickListener CancelOnClickListener =新Button.OnClickListener(){
@覆盖
公共无效的onClick(查看为arg0){
dismissDialog(CUSTOM_DIALOG_ID);
}
};}
对于初学者来说,你不需要在你的onCreate()这一行:
DP =(的DatePicker)findViewById(R.id.notdate);
由于您的DatePicker查看是不是在屏幕上但这种将返回null给你你的onCreate()内;
在onCreateDialog里面我觉得你只需要使它:
DP =(的DatePicker)dialog.findViewById(R.id.notdate);
这应该解决您的空指针。
Well ,thats my code.I want to take values from a DatePicker from a custom Dialog. When i try to initialize dp (DatePicker) i got a nullPointerException error and i cant take the values from DatePicker to variables. :/ Anyone knows what is going on? (I have 1 layouts. The main (R.layout.notifications) and the dialog layout (R.layout.notifications_dialog) the datepicker is on the notifications_dialog layout.
public class Notifications extends Activity {
static final int CUSTOM_DIALOG_ID = 0;
EditText Notification, Freq;
Button Save, Cancel;
int Year, Month , Day ;
DatePicker dp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.notifications);
Button ok = (Button) findViewById(R.id.ok);
dp=(DatePicker)findViewById(R.id.notdate);
ok.setOnClickListener(new OnClickListener() {
public void onClick(View ovuinfo) {
showDialog(CUSTOM_DIALOG_ID);
}
});
}
@Override
protected Dialog onCreateDialog(int id) {
Dialog dialog = null;;
switch(id) {
case CUSTOM_DIALOG_ID:
dialog = new Dialog(Notifications.this);
dialog.setContentView(R.layout.notifications_dialog);
dialog.setTitle("Add Notification");
Notification = (EditText)dialog.findViewById(R.id.notification);
Freq = (EditText)dialog.findViewById(R.id.freq);
Save = (Button)dialog.findViewById(R.id.add);
Cancel = (Button)dialog.findViewById(R.id.canc);
dp=(DatePicker)findViewById(R.id.notdate);
final Calendar cal = Calendar.getInstance();
int year = cal.get(Calendar.YEAR);
int monthOfYear = cal.get(Calendar.MONTH);
int dayOfMonth = cal.get(Calendar.DAY_OF_MONTH);
// here is the problem!
dp.init(year, monthOfYear, dayOfMonth, new OnDateChangedListener() {
@Override
public void onDateChanged(DatePicker view, int year, int monthOfYear,int dayOfMonth) {
Year = year;
Month = monthOfYear;
Day = dayOfMonth;
}
});
Save.setOnClickListener(SaveOnClickListener);
Cancel.setOnClickListener(CancelOnClickListener);
break;
}
return dialog;
}
private Button.OnClickListener SaveOnClickListener = new Button.OnClickListener(){
@Override
public void onClick(View arg0) {
String not = Notification.getText().toString();
String fre = Freq.getText().toString();
Toast toast = Toast.makeText(getApplicationContext(), not+":"+fre+":"+Day+"-"+Month+"-"+Year, Toast.LENGTH_SHORT);
toast.show();
}
};
private Button.OnClickListener CancelOnClickListener = new Button.OnClickListener(){
@Override
public void onClick(View arg0) {
dismissDialog(CUSTOM_DIALOG_ID);
}
};
}
For starters, you don't need this line in your onCreate():
dp=(DatePicker)findViewById(R.id.notdate);
Since your DatePicker View is not on the screen yet this will return null to you inside your onCreate();
Inside the onCreateDialog I think you just need to make it:
dp = (DatePicker)dialog.findViewById(R.id.notdate);
That should fix your null pointer.
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