android 禁止螢幕旋轉 (強制設定為縱向或橫向)

於 AndroidManifest.xml 檔裡, 在 <activity> </activity> 中, 添加一條屬性資訊：

android:screenOrientation="portrait"       （強制縱向）
android:screenOrientation="landscape"  （強制橫向）

如下:

<activity android:name=".SomeActivity"
    android:label="@string/app_name"
    android:screenOrientation="portrait">

android 寫入檔案 (簡短文字) FileInputStream, FileOutputStream

寫入簡短文字可使用寫入文字檔方法, 如複雜便要用SQLite

版面要加入一個editView, 一個textView 及 兩個 Button (editView1, textView2, btnWrite, btnRead)

輸入字於 editView1, 按下 btnWrite 便會寫入檔案 output 及顯示檔案路徑 (toast), 按下 btnRead 便會讀出檔案及顯示於 textView2





注意: 讀取中文字, 中文字每個要 2 個 Byte.

MainActivity.java

import android.content.Context;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

public class MainActivity extends ActionBarActivity {

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

        final EditText txtWrite = (EditText) findViewById(R.id.editText1);
        final TextView txtRead = (TextView) findViewById(R.id.textView2);

        Button btnTxtRead = (Button) findViewById(R.id.btnRead);
        Button btnTxtWrite = (Button) findViewById(R.id.btnWrite);


        btnTxtWrite.setOnClickListener(new View.OnClickListener() {
            @Override            public void onClick(View arg0) {

                try {
                    FileOutputStream fos = openFileOutput("output", Context.MODE_PRIVATE);
                    fos.write(txtWrite.getText().toString().getBytes());
                    fos.close();

                    File file = new File(getFilesDir() + "/" + fos);
                    Toast.makeText(getApplicationContext(), file.getAbsolutePath(), Toast.LENGTH_SHORT).show();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });

        btnTxtRead.setOnClickListener(new View.OnClickListener() {
            @Override            public void onClick(View arg0) {

                FileInputStream fos = null;
                BufferedInputStream buffered = null;

                try {
                    fos = openFileInput("output");
                    buffered = new BufferedInputStream(fos);
                    byte[] buffbyte = new byte[200];
                    txtRead.setText("");
                    do {
                        int flag = buffered.read(buffbyte);
                        if (flag == -1) {
                            break;
                        } else {
                            txtRead.append(new String(buffbyte), 0, flag);
                        }
                    }while (true);
                    buffered.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
}

android 日期比較

版面要加入兩個 textView 及 一個 Button (textView1, textView2, ChooseDateBtn)
此例以按選擇日子與現時日子作相減, 日子以微秒計算, 所以用 getTimeInMillis() 取得微秒後相減, 得出結果後再轉為秒, 分, 時, 日.

1000微秒 = 1秒

如要將時分秒設定為 0 用作計算, 可用 clear, 以下面為例, 現時日子可加入以下三句便可將時分秒設定為 0.

rightNow.clear(Calendar.HOUR);
rightNow.clear(Calendar.MINUTE);
rightNow.clear(Calendar.SECOND);

import android.app.DatePickerDialog;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;
import java.util.Calendar;
import java.util.GregorianCalendar;

public class MainActivity extends ActionBarActivity {

    Calendar rightNow = Calendar.getInstance();
    TextView DisplayDate1;
    TextView DisplayDate2;
    int cmonth, rmonth;


    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button changeDate = (Button) findViewById(R.id.ChooseDateBtn);
        DisplayDate1 = (TextView) findViewById(R.id.textView1);
        DisplayDate2 = (TextView) findViewById(R.id.textView2);

        changeDate.setOnClickListener(new View.OnClickListener() {

            @Override            public void onClick(View arg0) {

                new DatePickerDialog(MainActivity.this, d,
                        rightNow.get(Calendar.YEAR), rightNow.get(Calendar.MONTH),
                        rightNow.get(Calendar.DAY_OF_MONTH)).show();

            }
        });
    }

    DatePickerDialog.OnDateSetListener d = new DatePickerDialog.OnDateSetListener() {

        @Override        public void onDateSet(DatePicker view, int year, int monthOfYear,
                              int dayOfMonth) {


            cmonth = monthOfYear + 1;
            rmonth = rightNow.get(Calendar.MONTH) + 1;



            Calendar c = new GregorianCalendar(year, monthOfYear, dayOfMonth,
                    rightNow.get(Calendar.HOUR_OF_DAY), rightNow.get(Calendar.MINUTE),
                    rightNow.get(Calendar.SECOND));

            long diff = c.getTimeInMillis() - rightNow.getTimeInMillis();
            long diffSec = diff / 1000;
            long diffMins = diff / (60 * 1000);
            long diffHrs = diff / (60 * 60 * 1000);
            long diffDays = diff / (24 * 60 * 60 * 1000);


            DisplayDate1.setText("Choosen date is :" + dayOfMonth + "/" + cmonth + "/" + year +
                    "  Millisecond is :" + c.getTimeInMillis() + "\n" + "Current date is :" +
                    rightNow.get(Calendar.DAY_OF_MONTH) + "/" +
                    rmonth + "/" + rightNow.get(Calendar.YEAR) +
                    "  Millisecond is :" + rightNow.getTimeInMillis());
            DisplayDate2.setText("Date difference in seconds: " + diffSec +"\n"+
                    "Date difference in minutes: "+diffMins+"\n"+ "Date difference in hours: "+
                    diffHrs +"\n"+"Date difference in days: " + diffDays);



        }
    };
}

android DatePickerDialog 彈出日期選擇

注意:

版面要加入一個 textView 及 一個 Button (textView1, ChooseDateBtn)

import android.app.DatePickerDialog;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;

import java.util.Calendar;

public class MainActivity extends ActionBarActivity {

    Calendar c = Calendar.getInstance();
    TextView DisplayDate;
    int cday, cmonth, cyear;

    @Override     

       protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button changeDate = (Button) findViewById(R.id.ChooseDateBtn);
        DisplayDate = (TextView) findViewById(R.id.textView1);

        changeDate.setOnClickListener(new OnClickListener() {

            @Override             

             public void onClick(View arg0) {

                new DatePickerDialog(MainActivity.this, d,
                        c.get(Calendar.YEAR), c.get(Calendar.MONTH), c.get(Calendar.DAY_OF_MONTH)).show();

            }
        });
    }

    DatePickerDialog.OnDateSetListener d = new DatePickerDialog.OnDateSetListener() {

        @Override 

            public void onDateSet(DatePicker view, int year, int monthOfYear,
                              int dayOfMonth) {

            cday = dayOfMonth;
            cmonth = monthOfYear + 1;
            cyear = year;

            DisplayDate.setText("Choosen date is :" + cday + "/" + cmonth + "/" + cyear);
        }
    };
}

android DatePicker 日期選擇

以下是簡單日期選擇例子

注意:

版面要加入兩個 textView 及 一個 DatePick (textView1, textView2, datePicker1)

因 Bug 關係, DatePick 放置後會顯示 Rendering Problems, 及不會顯示 DatePick, 但 run app 後會在 app 顯示

預設日期

datepick.init(2016,1,4,onDateChanged);

月份係由 0 至 11, 當顯示數字時要加 1, array 係由 0 開始, 所以不須要

Integer.toString(monthOfYear+1)

加入此兩個可改變日期選擇為轉動選擇

datepick.setCalendarViewShown(false);
datepick.setSpinnersShown(true);

import android.app.Activity;
import android.os.Bundle;
import android.widget.DatePicker;
import android.widget.TextView;


public class MainActivity extends Activity {
    @Override    protected void onCreate(Bundle savedInstanceState)  {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        DatePicker datepick = (DatePicker)
                findViewById(R.id.datePicker1);
        datepick.init(2016,1,4,onDateChanged);
        //    datepick.setCalendarViewShown(false); 

        //    datepick.setSpinnersShown(true);    }

    DatePicker.OnDateChangedListener onDateChanged=
            new DatePicker.OnDateChangedListener() {
                @Override                 

              public void onDateChanged(
                        DatePicker view,
                        int year,
                        int monthOfYear,
                        int dayOfMonth) {
                    final String[] MMM = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
                    TextView tv1 = (TextView)findViewById(R.id.textView1);
                    TextView tv2 = (TextView)findViewById(R.id.textView2);
                    
                    tv1.setText(Integer.toString(dayOfMonth) +
                            "/"+Integer.toString(monthOfYear+1)+
                            "/"+Integer.toString(year) );

                    tv2.setText(Integer.toString(dayOfMonth) +
                            "/"+(MMM[monthOfYear])+
                            "/"+Integer.toString(year) );
                                    }
            };
}

旅行注意事項, 護照有效期, 旅遊保險, 匯率, 電壓、插頭

近日準備外遊, 為日後方便, 記下以下重要事項, 方便日後使用.

• 護照有效期
• 最少有六個月

• 護照複印本, 以便護照被竊或遺失時, 迅速申請補發.

• 香港特別行政區護照免簽證情況一覽表

• 旅遊保險
• 通常在出機票後, 或預訂酒店後, 便會購買, 有甚麼意外去唔到都有保障, 以下有旅遊保險比可作參考 
• http://www.moneyhero.com.hk/zh/travel-insurance/get-quote#step1

• 匯率
• 通常都到以下百年網頁作參考 
• http://bcel1985.blogspot.hk/

• 世界各國電壓、插頭型式一覽表
• http://www.yung-li.com.tw/tw/info/ww_specifications.htm
• 世界各國電源插頭插座形式

• 注意隨身物品
• 尤其是長途機, 重要物品要隨身攜帶, 小偷會在乘客睡眠及離開坐位, 偷去放於坐位, 前坐椅下, 椅下或坐椅上的行李置物櫃.

設定 blog 所顯示圖片大小

如發現預設圖片顯示有點小, 可從設定中統一圖片大小, 到 "範本" > "自訂"

再到 "進階" > "新增 CSS"

填寫如下:

.post-body img {
width: 500px;
height: auto; }

.post table.tr-caption-container img {
width: 500px;
height: auto;
}

當中 .post-body img 為沒有加標題的圖片, .post table.tr-caption-container 為加有標題的圖片, width 為闊, height 為高.