Eclipse使用Android遇到的問題處理:

A.找不到Android.Support.V7的問題:
 參考如下http://oldgrayduck.blogspot.tw/2013/10/android-support-library.html

Javascript 繪圖

A.統計繪圖:

 來源:http://www.chartjs.org/
  import: <script src="components/com_foxparsing/Chart.js-master/Chart.js"></script>



B.解決因數值過多,造成x軸labels過度擁擠無法顯示數值的問題.
 

ANS:找到Chart.js在大約938行的calculateXAxisSize函式.

將valueHop = Math.floor(xAxisLength/(data.labels.length-1)); 改成

valueHop = xAxisLength/(data.labels.length-1);

Linux 網路指令

A.繞回介面:
    目的:有時繞回介面才能運作
    指令:  ifconfig lo 127.0.0.1



B.找網路介面:
 dmesg | grep eth


C.查詢本機網路和外界網路連線的指令
  netstat -nr


D.修改路由表:
 route [add | del] [-net | -host] destination [if]

E.觀察網路介面組態
  /sbin/ifconfig lo

F.測試整個TCP/IP協定模組是否能順利運作
 ssh localhost

HTML 5 特性:

<canvas id='ss' ...  > </canvas>
最大的width:32750

Android 範例 source code:

1>4>9 宮格:

https://drive.google.com/file/d/0B1cKGi6s-QMTSTZ1Q2xEV1FJOWc/edit?usp=sharing

Android 4.3 的Thread應用:
package com.example.smartheartrate;

import java.util.Random;

import android.app.Activity;
import android.app.Fragment;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

public class MainActivity extends Activity {

static int count = 0;

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


if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit();
}
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}

/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {

public PlaceholderFragment() {
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);

System.out.println("start in");
final TextView wordToGuess = (TextView) rootView.findViewById(R.id.text);


final Handler hr;
hr = new Handler(){
            public void handleMessage(Message msg) {
                switch(msg.what){
               
                case 1:
                 
                int newvalue = -1;
           
                do{
                newvalue = new Random().nextInt(120);
               
                }while(newvalue < 88);              
               
                    wordToGuess.setText("HR:"+ newvalue);
               
                break;
                }                        
                super.handleMessage(msg);
            }
       };
     
       new Thread(new Runnable(){
           public void run(){
             
               while(true){
               try {
                   Thread.sleep(1000);
               } catch (InterruptedException e) {
                   // TODO Auto-generated catch block
                   e.printStackTrace();
               }

               Message m = new Message();                              
                m.what = 1;              
                hr.sendMessage(m);              
               }                      
           }
       }).start();


return rootView;
}
}

}

Android Eclipse 錯誤處理

(1) R cannot be resolved to a variable

 在Eclipse中某一個xml檔案沒有寫好,導致語法錯誤,會導致此問題

(2)
每當過一段時間,使用Android Eclipse會產生錯誤,因為android在遠端已經通知本地需要升級,但Eclipse並沒有被同步到

需要進行兩處的更新

A.進SDK Manager:勾選SDK Platform-tools進行更新
   

B.在Eclipse的Help-> Install New Software進入 https://dl-ssl.google.com/android/eclipse/ 做更新.

重新啟動Eclipse