程式設計@筆記

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MainActivity.java
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package ecodesign.alertdialog;
import android.app.DatePickerDialog;
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;

import java.util.Calendar;


public class MainActivity extends Activity {
    private int mYear, mMonth, mDay;

    private String setDateFormat(int year,int monthOfYear,int dayOfMonth){
        return String.valueOf(year) + "-"
+ String.format("%02d", monthOfYear + 1) + "-"
+ String.format("%02d",dayOfMonth);
    }

    @Override
protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final TextView dateText = (TextView)findViewById(R.id.dateText);
        Button dateButton = (Button)findViewById(R.id.dateButton);
        dateButton.setOnClickListener(new View.OnClickListener(){
            @Override
public void onClick(View view) {
                final Calendar c = Calendar.getInstance();
                mYear = c.get(Calendar.YEAR);
                mMonth = c.get(Calendar.MONTH);
                mDay = c.get(Calendar.DAY_OF_MONTH);
                new DatePickerDialog(MainActivity.this, new DatePickerDialog.OnDateSetListener() {
                    @Override
public void onDateSet(DatePicker view, int year, int month, int day) {
                        //String format = getString(R.string.set_date) + setDateFormat(year,month,day);
String format = setDateFormat(year,month,day);
                        dateText.setText(format);
                    }
                }, mYear,mMonth, mDay).show();
            }
        });
    }
}

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activity_main.xml
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<?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:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin">

    <Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Date"
android:id="@+id/dateButton"
/>
    <TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/dateText"
/>
</LinearLayout>