監聽應用程序安裝卸載/ app install BroadcastReceiver

package com.example.testgetinstalledapp;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

public class refreshapp_br extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent arg1) {
// TODO Auto-generated method stub

String action = arg1.getAction();

if (Intent.ACTION_PACKAGE_REMOVED.equals(action)) {
//Log.d(TAG, "package has been removed");
String packageName = arg1.getData().getSchemeSpecificPart();
//Log.d(TAG, packageName);
Toast.makeText(context, "   "+packageName, Toast.LENGTH_SHORT).show();
} else if (Intent.ACTION_PACKAGE_ADDED.equals(action)) {
//Log.d(TAG, "package has been added");
String packageName = arg1.getData().getSchemeSpecificPart();
Toast.makeText(context, "   "+packageName, Toast.LENGTH_SHORT).show();
}
}

}

----------------------------------------------------------------------------------

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.example.testgetinstalledapp"

    android:versionCode="1"

    android:versionName="1.0" >

    <uses-sdk

        android:minSdkVersion="8"

        android:targetSdkVersion="17" />

    <application

        android:allowBackup="true"

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name"

        android:theme="@style/AppTheme" >

        <activity

            android:name="com.example.testgetinstalledapp.MainActivity"

            android:label="@string/app_name" >

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

        

        <receiver android:name="com.example.testgetinstalledapp.refreshapp_br" >

            <intent-filter android:priority="999" >

                <action android:name="android.intent.action.PACKAGE_ADDED" />

                <action android:name="android.intent.action.PACKAGE_REMOVED" />

                <data android:scheme="package" />

            </intent-filter>

        </receiver>

    </application>

</manifest>

write_in() & read_in() (folder in folder) (internal)

protected void write_in(String string, String string2, String string3) {
// TODO Auto-generated method stub
// This will get the SD Card directory and create a folder named MyFiles
// in it.
File sdCard = getFilesDir();
File directory = new File(sdCard.getAbsolutePath() + "/" + string);

// Now create the file in the above directory and write the contents
// into it
File file = new File(directory, string2);
FileOutputStream fOut = null;
try {
fOut = new FileOutputStream(file);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
OutputStreamWriter osw = new OutputStreamWriter(fOut);
try {
osw.write(string3);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
osw.flush();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
osw.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

-------------------------------------------------------------------

private String read_in(String directory, String string) {
// TODO Auto-generated method stub
// Read in. st. from File"fi"
String fileName = string;
int readed;
String content = "";
byte[] buff = new byte[256]; // input stream buffer
// Input stream
try {
File file = new File(getFilesDir() + "/" + directory, string);
FileInputStream reader = new FileInputStream(file);
// FileInputStream reader =
// context.getApplicationContext().openFileInput(fileName);
while ((readed = reader.read(buff)) != -1) {
content += new String(buff).trim();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// End of Read in. st. from File"fi"
return content;
}

Internal Storage Create Folder (Folder in Folder)

File myDir = new File(getFilesDir(), "folder");
myDir.mkdir();


File myDir2 = new File(getFilesDir()+"/folder", "folder2");
myDir2.mkdir();

Custom Market API / Play Store API

https://play.google.com/store/apps/details?id=com.baseapp.eyeem&hl=en_GB

&hl=en_GB能強制將play store轉成英文

---------------------------------------------------
package com.example.marketapitest;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;

import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {
 
    public static final int DIALOG_DOWNLOAD_PROGRESS = 0;
    private Button startBtn;
    private ProgressDialog mProgressDialog;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        startBtn = (Button)findViewById(R.id.button1);
        startBtn.setOnClickListener(new OnClickListener(){
            public void onClick(View v) {
                startDownload();
            }
        });
    }

    private void startDownload() {
        String url = "https://play.google.com/store/apps/details?id=com.baseapp.eyeem&hl=en_GB";
        new DownloadFileAsync().execute(url);
    }
    @Override
    protected Dialog onCreateDialog(int id) {
        switch (id) {
  case DIALOG_DOWNLOAD_PROGRESS:
   mProgressDialog = new ProgressDialog(this);
   mProgressDialog.setMessage("Downloading file..");
   mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
   mProgressDialog.setCancelable(false);
   mProgressDialog.show();
   return mProgressDialog;
  default:
   return null;
        }
    }

class DownloadFileAsync extends AsyncTask<String, String, String> {
 
 @Override
 protected void onPreExecute() {
  super.onPreExecute();
  showDialog(DIALOG_DOWNLOAD_PROGRESS);
 }

 @Override
 protected String doInBackground(String... aurl) {
  int count;

 try {

 URL url = new URL(aurl[0]);
 URLConnection conexion = url.openConnection();
 conexion.connect();

 int lenghtOfFile = conexion.getContentLength();
 Log.d("ANDRO_ASYNC", "Lenght of file: " + lenghtOfFile);



 InputStream input = new BufferedInputStream(url.openStream());
 String fullPath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/TFFolder";
 File dir = new File(fullPath);
 if (!dir.exists()) {
 dir.mkdirs();
 }
 OutputStream output = new FileOutputStream(fullPath+"/123.txt");



 byte data[] = new byte[1024];

 long total = 0;

  while ((count = input.read(data)) != -1) {
   total += count;
   publishProgress(""+(int)((total*100)/lenghtOfFile));
   output.write(data, 0, count);
  }

  output.flush();
  output.close();
  input.close();
 } catch (Exception e) {}
 return null;

 }
 protected void onProgressUpdate(String... progress) {
   Log.d("ANDRO_ASYNC",progress[0]);
   mProgressDialog.setProgress(Integer.parseInt(progress[0]));
 }

 @Override
 protected void onPostExecute(String unused) {
  dismissDialog(DIALOG_DOWNLOAD_PROGRESS);
 }
}
}

-------------------------------------------------------------------

mysplit

private List<String> mysplit(String input) {
// TODO Auto-generated method stub
List<String> output=new ArrayList();
String temp = "";
for(int i=0;i<input.length();i++){
if(input.toCharArray()[i]!='\\'  )
temp+=input.toCharArray()[i];
else{
output.add(temp);
temp = "";
}

}
output.add(temp);
return output;
}

Android程序完全退出的方法

 System.exit(0);   //常规java、c#的标准退出法，返回值为0代表正常退出

Android Bitmap OOM系列（2）：利用convertView/holder 改良GridView

撰寫於2012年09月29日| 沒有評論

      在上一篇日誌《Android Bitmap OOM系列（1）：GridView》中，我們已經成功的讓GridView跑起來了，但是這是最最原始的實現方式之一，它的效率也是非常之低（我們的圖片都是來自於項目中，而且都是微小圖片，所以感受不到），一旦圖片的分辨率比較大，而且圖片數量多的話，應用很容易因為內存爆掉而導致FC（Force close）。這是因為我們在getView方法中始終是new一個新的View出來，如此一來，一旦有100張圖，我們就要new 100次，同時當我們滾動GridView的時候，即使是顯示在界面上過的View也會重新new一次。而同時Dalvik虛擬機又未能及時回收已不用的內存，當到達極限時，內存也就理所當然地爆掉了。

      在寫getView這個方法中的代碼時，我們已經發現，getView有一個參數View(參數名為convertView),在android的ListView、Gridview中，convertView是一個很有用，而且很酷的參數。根據官方文檔的解釋，它是用來在可能的情況下重用舊的視圖的。在使用之前，我們應該先檢查這個view不是空的而且是一個適當的類型。所以呢，我們現在就來把getView給改寫一下。改寫後的代碼如下：

View view = null ; 
if  ( convertView ==  null )  { 
 view = mInflater . inflate ( R . layout . gridview ,  null ); 
        ImageView imageView =  ( ImageView ) convertView . findViewById ( R . id . image ); 
 imageView . setImageBitmap ( bitmapList . get ( position )); 
} else { 
        view = convertView
 } 
return view ;

    首先我們判斷convertView是否為空，當為空時，就按照原來的邏輯去xml中尋找控件並實例化出來，然後把BItmap設置進ImageView,如果不為空，就直接將convertView賦給view。

    這次的改寫就這麼簡單，當然這個還是簡單的形式，因為我們現在只有一個ImageView而已，如果在項目中我們GridView的每一個View都是由多個控件組成（比如一個ImageView和一個TextView），那麼我們還需要建一個holder來儲存。首先我們需要建一個holder類（我比較喜歡直接寫在adapter裡作為內部類使用），它只包含2個成員變量

public  class  Holder { 
           public  TextView text ; 
           public  ImageView image ; 
}

然後在getView中使用這個holder，首先我們先實例化Holder為null，然後如同上面那樣判斷convertView是否為空，並進行相應的實例化操作。所不同的是，這裡我們不再需要new 一個ImageView出來了，我們直接把xml中讀出來的ImageView賦值給Holder的成員變量image,TextView也一樣。然後分別給他們設ImageBitamp和Text，之後把Holder設置到convertView裡面去。當convertView不為空的時候，則從convertView中取出相應Holder的視圖出來。

View view = null ; 
Holder holder = null ; 
if  ( convertView ==  null )  { 
 view = mInflater . inflate ( R . layout . gridview ,  null ); 
        holder =  new  Holder (); 
        holder . image =  ( ImageView ) convertView . findViewById ( R . id . image ); 
 holder . image . setImageBitmap ( bitmapList . get ( position )); 
        convertVIew . setTag ( holder ); 
} else { 
        view = convertView . getTag (); 
} 
return view ;

原創文章，轉載請註明：轉載自網憩閣

Google的教學:

https://dl.google.com/googleio/2010/android-world-of-listview-android.pdf

getView

static class ViewHolder { 
TextView text; 
ImageView icon; 
}


------------------------------------------------
ViewHolder holder; 

 if (convertView == null) { 
 convertView = mInflater.inflate(R.layout.list_item_icon_text, 
  parent, false);
 holder = new ViewHolder(); 
  holder.text = (TextView) convertView.findViewById(R.id.text); 
  holder.icon = (ImageView) convertView.findViewById(R.id.icon); 

  convertView.setTag(holder); 
  } else { 
  holder = (ViewHolder) convertView.getTag(); 
  } 

  holder.text.setText(DATA[position]); 
  holder.icon.setImageBitmap((position & 1) == 1 ? mIcon1 : mIcon2); 

 return convertView; 
-----------------------------------------------------------


public class MyBaseAdapter extends BaseAdapter {

private Context myContext;

MyBaseAdapter(Context c) {
myContext = c;
}
public class ViewHolder { 
TextView text; 
ImageView icon; 
}
@Override
public int getCount() {
return MyAppList.size();
}

@Override
public Object getItem(int position) {
return MyAppList.get(position);
}

@Override
public long getItemId(int position) {
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

/*View MyView = convertView;

if (convertView == null) {

MyView = new View(myContext);
MyView.setLayoutParams(new GridView.LayoutParams(85, 85));
// MyView.setScaleType(View.ScaleType.CENTER_CROP);
MyView.setPadding(8, 8, 8, 8);
} else {
MyView = (View) convertView;
}


LayoutInflater li = getLayoutInflater();
MyView = li.inflate(R.layout.grid_item, null);

// Add The Text!!!
TextView tv = (TextView) MyView.findViewById(R.id.tv);
tv.setText(MyAppList.get(position));

// Add The Image!!!

ImageView iv = (ImageView) MyView.findViewById(R.id.imageView1);
iv.setScaleType(ImageView.ScaleType.CENTER_CROP);
iv.setImageBitmap(getThumbnail("icon " + MyAppList.get(position)
+ ".png", getBaseContext()));

return MyView;*/

ViewHolder holder; 
LayoutInflater li = getLayoutInflater();
if (convertView == null) { 
convertView = li.inflate(R.layout.grid_item, 
 parent, false);
holder = new ViewHolder(); 
 holder.text = (TextView) convertView.findViewById(R.id.tv); 
 holder.icon = (ImageView) convertView.findViewById(R.id.imageView1); 
 
 convertView.setTag(holder); 
 } else { 
 holder = (ViewHolder) convertView.getTag(); 
 } 
 
 holder.text.setText(MyAppList.get(position)); 
 holder.icon.setImageBitmap(getThumbnail("icon " + MyAppList.get(position)
+ ".png", getBaseContext())); 
 
return convertView; 

}

}

"不再" Force close的 gridview
忽略一些東西, 能換來一些東西