(Android Note) 驗證是否有網路連線

1. code 

//判斷當前網路連接狀態  、0 無連接 、1 3G、2 WIFI
public static int checkNetworkInfo(Context context){
  int stateType = 0;
ConnectivityManager cm = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
State mobile = 
cm.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState(); //取得3G連線狀態
State wifi = 
cm.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState(); //取得WIFI連線狀態
if (mobile == State.CONNECTED || mobile == State.CONNECTING){
stateType = 1;
}
if (wifi == State.CONNECTED || wifi == State.CONNECTING){
stateType = 2;
}
return stateType;
}

• • 
    
  *AndroidManifest 開啟權限

• <uses-permissionandroid:name="android.permission.ACCESS_NETWORK_STATE" /> //訪問存取網路狀態許可權限
• <uses-permissionandroid:name="android.permission.ACCESS_WIFI_STATE" /> //訪問存取wifi狀態許可權限
• <uses-permission android:name="android.permission.MODIFY_PHONE_STATE" /> //訪問存取手機狀態許可權限

(Android Note) AlertDialog.Builder

1. Code

final AlertDialog.Builder builder=new AlertDialog.Builder(this);
builder.setTitle(" Test ");
builder.setMessage(" Test ");
builder.setIcon(android.R.drawable.ic_dialog_alert);

//3種事件處理方式
builder.setPositiveButton("OK", new OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {

    }
});

builder.setNegativeButton("Cancel", new OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
    // TODO Auto-generated method stub

    }
});

builder.setNeutralButton("other things", new OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
    // TODO Auto-generated method stub

    }
});

builder.show();

(Android Note) 內部和外部儲存空間大小

1. Code

(1) sdcard 是否存在


android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);
return true; //存在
return false; //不存在

(2) 內部儲存空間


File path = android.os.Environment.getDataDirectory();
StatFs sf = new StatFs(path.getPath());
long bs = sf.getBlockSize();
long ab = stat.getAvailableBlocks();
long bc = stat.getBlockCount();

retrun bs*ab; //剩餘儲存空間
retrun bs*bc; //總儲存空間

(3) sdcard儲存空間


File path = android.os.Environment.getExternalStorageDirectory();
StatFs sf = new StatFs(path.getPath());
long bs = sf.getBlockSize();
long ab = stat.getAvailableBlocks();
long bc = stat.getBlockCount();

retrun bs*ab; //剩餘儲存空間
retrun bs*bc; //總儲存空間


2. 說明

bs(block size)，在fat32檔案系統， block size是 4096 byte，其他可以用getBlockSize()來找出block size 大小。