程式小試身手

package com.jpyu.sdcard;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class sdcardActivity extends Activity {
/** Called when the activity is first created. */
// GUI controls
EditText txtData;
Button btnWriteSDFile;
Button btnReadSDFile;
Button btnClearScreen;
Button btnClose;
private final String SD_PATH = android.os.Environment
.getExternalStorageDirectory().getAbsolutePath();
public static final String FILE_PATH = "/fileio";
private final String INPUT_FILENAME = "file.doc";
String dirPath = SD_PATH+FILE_PATH+"/";
String filenameWithPath = SD_PATH+FILE_PATH+"/"+INPUT_FILENAME;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findViews();
setListener();
}// onCreate
private void findViews() {
// bind GUI elements with local controls
txtData = (EditText) findViewById(R.id.txtData);
txtData.setHint("Enter some lines of data here...");
btnWriteSDFile = (Button) findViewById(R.id.btnWriteSDFile);
btnReadSDFile = (Button) findViewById(R.id.btnReadSDFile);
btnClearScreen = (Button) findViewById(R.id.btnClearScreen);
btnClose = (Button) findViewById(R.id.btnClose);
}
private void setListener() {
btnWriteSDFile.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
writeFileToSdcardv2();
}// onClick
}); // btnWriteSDFile
btnReadSDFile.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
readFileFromSdcardv1();
}// onClick
}); // btnReadSDFile
btnClearScreen.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// clear text box
txtData.setText("");
}
}); // btnClearScreen
btnClose.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// clear text box
finish();
}
}); // btnClose
}
void readFileFromSdcardv1(){
try {
File myFile = new File(filenameWithPath);
FileInputStream fIn = new FileInputStream(myFile);
BufferedReader myReader = new BufferedReader(
new InputStreamReader(fIn));
String aDataRow = "";
String aBuffer = "";
while ((aDataRow = myReader.readLine()) != null) {
aBuffer += aDataRow + "\n";
}
txtData.setText(aBuffer);
myReader.close();
Toast.makeText(getBaseContext(),
"Done reading SD 'mysdfile.txt'",
Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(),
Toast.LENGTH_SHORT).show();
}
}
void writeFileToSdcardv1(){
// write on SD card file data in the text box
try {
File myFile = new File(filenameWithPath);
myFile.createNewFile();
FileOutputStream fOut = new FileOutputStream(myFile);
OutputStreamWriter myOutWriter =
new OutputStreamWriter(fOut);
myOutWriter.append(txtData.getText());
myOutWriter.close();
fOut.close();
Toast.makeText(getBaseContext(),
"Done writing SD 'mysdfile.txt'",
Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(),
Toast.LENGTH_SHORT).show();
}
}
void writeFileToSdcardv2(){
// write on SD card file data in the text box
try {
// create a File object for the parent directory
File newDir = new File(dirPath);
// have the object build the directory structure, if needed.
newDir.mkdirs();
File myFile = new File(filenameWithPath);
myFile.createNewFile();
FileOutputStream fOut = new FileOutputStream(myFile);
OutputStreamWriter myOutWriter =
new OutputStreamWriter(fOut);
myOutWriter.append(txtData.getText());
myOutWriter.close();
fOut.close();
Toast.makeText(getBaseContext(),
"Done writing SD 'mysdfile.txt'",
Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(getBaseContext(), e.getMessage(),
Toast.LENGTH_SHORT).show();
}
}
}

public class Comment {
private long id;
private String comment;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getComment() {
return comment;
}
public void setComment(String comment) {
this.comment = comment;
}
// Will be used by the ArrayAdapter in the ListView
@Override
public String toString() {
return comment;
}
}

下載JAR
http://square.github.io/picasso/

package com.example.chen.task;
import android.app.ProgressDialog;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import com.squareup.picasso.Picasso;
import java.io.BufferedInputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
public class MainActivity extends AppCompatActivity {
Button button;
ProgressDialog progressBar;
ImageView imageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button)findViewById(R.id.button);
imageView=(ImageView)findViewById(R.id.imageView);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
new GetImage().execute("http://content.teldap.tw/index/files/image/epaper/34/bio.JPG");
// Picasso.with(MainActivity.this).load("http://www.google.com/logos/2013/estonia_independence_day_2013-1057005.3-hp.jpg").into(imageView);
}
});
}
private class GetImage extends AsyncTask<String , Integer , Bitmap> {
@Override
protected void onPreExecute() {
//執行前 設定可以在這邊設定
super.onPreExecute();
progressBar = new ProgressDialog(MainActivity.this);
progressBar.setMessage("Loading...");
progressBar.setCancelable(false);
progressBar.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
progressBar.show();
}
@Override
protected Bitmap doInBackground(String... params) {
//執行中 在背景做事情
int count =params.length;
Bitmap mybitmap;
try {
Log.i("mytest",params[0]);
/* URL url = new URL(params[0]);
HttpURLConnection con = (HttpURLConnection)url.openConnection();
InputStream is = con.getInputStream();
bitmap2 = BitmapFactory.decodeStream(is );
*/
URL aURL = new URL(params[0]);
URLConnection conn = aURL.openConnection();
conn.connect();
InputStream is = conn.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
mybitmap = BitmapFactory.decodeStream(bis);
bis.close();
is.close();
if (null != mybitmap)
return mybitmap;
} catch (Exception e) {
e.printStackTrace();
}
for (int i = 0; i < count; i++) {
publishProgress((int) ((i / (float) count) * 100));
// Escape early if cancel() is called
}
publishProgress(100);
//最後達到100%
return null;
}
@Override
protected void onProgressUpdate(Integer... values) {
//執行中 可以在這邊告知使用者進度
super.onProgressUpdate(values);
progressBar.setProgress(values[0]);
}
@Override
protected void onPostExecute(Bitmap bitmap) {
//執行後 完成背景任務
progressBar.dismiss();
//當完成的時候，把進度條消失
imageView.setImageBitmap( bitmap);
}
}
}

參考資料1的內容擷取:
JSON有兩種方式來寫入資料，一種是陣列（Array）[]，另一種是物件（Object）{}。

前言:
不用傳統執行緒，而用此是因為佔據主執行緒太久的時間，會當掉(系統設定)。

前言:
Bootstrap tree不知是不是更新事件太基礎，中文版超難找...終於在眾多英文網站中看出端倪

環境
這是試用版30天

環境
因為是學生，學校有購買Dreamspark 使用權限，所以可以到Dreamspark下載軟體

 
參考資料: