程式小試身手

官方寫的滿清楚的

關鍵句

繪矩形

PolylineOptions rectOptions = new PolylineOptions() .add(new LatLng(37.35, -122.0)) .add(new LatLng(37.45, -122.0)) // North of the previous point, but at the same longitude  .add(new LatLng(37.45, -122.2)) // Same latitude, and 30km to the west  .add(new LatLng(37.35, -122.2)) // Same longitude, and 16km to the south  .add(new LatLng(37.35, -122.0)); // Closes the polyline.

關鍵在送出此API

 https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=座標&radius=搜尋範圍&types=種類&sensor=true&key=server api key

server api key(=金鑰) 要申請

官方網站: https://developers.google.com/places/web-service/

方法1: MarkerOptions markerOpt = new MarkerOptions(); markerOpt.position(new LatLng(25.033611, 121.565000)); markerOpt.title("台北101"); markerOpt.snippet("於1999年動工，2004年12月31日完工啟用，樓高509.2公尺。"); markerOpt.draggable(false); markerOpt.visible(true); markerOpt.anchor(0.5f, 0.5f);//設為圖片中心 markerOpt.icon(BitmapDescriptorFactory.fromResource(android.R.drawable.ic_menu_mylocation)); map.addMarker(markerOpt);

方法2:

map.addMarker(new MarkerOptions() .title(jObject.getJSONArray("results").getJSONObject(i).getString("name")) .snippet("The most populous place in Taiwan.") .position(new LatLng(mlatitude, mlongitude)));

方法1（參考資料１）:

double lat, lng; LocationManager lm = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE); Location location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER); // 設定定位資訊由 GPS提供 lat = location.getLatitude(); // 取得經度 lng = location.getLongitude(); // 取得緯度 LatLng HOME = new LatLng(lat, lng); map.moveCamera(CameraUpdateFactory.newLatLngZoom(HOME, 15.0f));//數字越大放越大

有更精準的類別可以使用↓

方法2:

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(); } } }

<?xml version="1.0" encoding="utf-8"?> <LinearLayout android:id="@+id/widget28" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="#ff0000ff" android:orientation="vertical" xmlns:android="http://schemas.android.com/apk/res/android" > <EditText android:id="@+id/txtData" android:layout_width="fill_parent" android:layout_height="180px" android:textSize="18sp" /> <Button android:id="@+id/btnWriteSDFile"  android:layout_width="251px"  android:layout_height="wrap_content" android:text="1. Write SD File" /> <Button android:id="@+id/btnClearScreen"  android:layout_width="251px"  android:layout_height="wrap_content" android:text="2. Clear Screen" /> <Button android:id="@+id/btnReadSDFile"  android:layout_width="251px"  android:layout_height="wrap_content" android:text="3. Read SD File" /> <Button android:id="@+id/btnClose"  android:layout_width="251px"  android:layout_height="wrap_content" android:text="4. Close" /> </LinearLayout> 

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; } } 

package com.example.ex_sqlite01; import java.util.ArrayList; import java.util.List; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; public class CommentsDataSource { // Database fields  private SQLiteDatabase database; private MySQLiteHelper dbHelper; private String[] allColumns = { MySQLiteHelper.COLUMN_ID, MySQLiteHelper.COLUMN_COMMENT }; public CommentsDataSource(Context context) { dbHelper = new MySQLiteHelper(context); } public void open() throws SQLException { database = dbHelper.getWritableDatabase(); } public void close() { dbHelper.close(); } public Comment createComment(String comment) { ContentValues values = new ContentValues(); values.put(MySQLiteHelper.COLUMN_COMMENT, comment); long insertId = database. insert(MySQLiteHelper.TABLE_COMMENTS, null,values); Cursor cursor = database.query (MySQLiteHelper.TABLE_COMMENTS, allColumns, MySQLiteHelper. COLUMN_ID + " = " + insertId, null, null, null, null); cursor.moveToFirst(); Comment newComment = cursorToComment(cursor); cursor.close(); return newComment; } public void deleteComment(Comment comment) { long id = comment.getId(); System.out.println("Comment deleted with id: " + id); database.delete(MySQLiteHelper.TABLE_COMMENTS, MySQLiteHelper.COLUMN_ID  + " = " + id, null); } public List<Comment> getAllComments() { List<Comment> comments = new ArrayList<Comment>(); Cursor cursor = database.query(MySQLiteHelper.TABLE_COMMENTS, allColumns, null, null, null, null, null); cursor.moveToFirst(); while (!cursor.isAfterLast()) { Comment comment = cursorToComment(cursor); comments.add(comment); cursor.moveToNext(); } // make sure to close the cursor  cursor.close(); return comments; } private Comment cursorToComment(Cursor cursor) { Comment comment = new Comment(); comment.setId(cursor.getLong(0)); comment.setComment(cursor.getString(1)); return comment; } } 

package com.example.ex_sqlite01; import java.util.List; import java.util.Random; import android.app.ListActivity; import android.os.Bundle; import android.view.View; import android.widget.ArrayAdapter; public class MainActivity extends ListActivity { private CommentsDataSource datasource; @Override  public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_mainsqlite); datasource = new CommentsDataSource(this); datasource.open(); List<Comment> values = datasource.getAllComments(); // use the SimpleCursorAdapter to show the  // elements in a ListView  ArrayAdapter<Comment> adapter = new ArrayAdapter<Comment>(this, android.R.layout.simple_list_item_1, values); setListAdapter(adapter); } // Will be called via the onClick attribute  // of the buttons in main.xml  public void onClick(View view) { @SuppressWarnings("unchecked") ArrayAdapter<Comment> adapter = (ArrayAdapter<Comment>) getListAdapter(); Comment comment = null; switch (view.getId()) { case R.id.add: String[] comments = new String[] { "Cool", "Very nice", "Hate it" }; int nextInt = new Random().nextInt(3); // save the new comment to the database  comment = datasource.createComment(comments[nextInt]); adapter.add(comment); break; case R.id.delete: if (getListAdapter().getCount() > 0) { comment = (Comment) getListAdapter().getItem(0); datasource.deleteComment(comment); adapter.remove(comment); } break; } adapter.notifyDataSetChanged(); } @Override  protected void onResume() { datasource.open(); super.onResume(); } @Override  protected void onPause() { datasource.close(); super.onPause(); } } 

package com.example.ex_sqlite01; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.util.Log; public class MySQLiteHelper extends SQLiteOpenHelper { public static final String TABLE_COMMENTS = "comments"; public static final String COLUMN_ID = "_id"; public static final String COLUMN_COMMENT = "comment"; private static final String DATABASE_NAME = "commments.db"; private static final int DATABASE_VERSION = 2; // Database creation sql statement  private static final String DATABASE_CREATE = "create table "  + TABLE_COMMENTS + "(" + COLUMN_ID  + " integer primary key autoincrement, " + COLUMN_COMMENT  + " text not null);"; public MySQLiteHelper(Context context) { super(context, DATABASE_NAME, null, DATABASE_VERSION); } @Override  public void onCreate(SQLiteDatabase database) { database.execSQL(DATABASE_CREATE); } @Override  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { Log.w(MySQLiteHelper.class.getName(), "Upgrading database from version " + oldVersion + " to "  + newVersion + ", which will destroy all old data"); db.execSQL("DROP TABLE IF EXISTS " + TABLE_COMMENTS); onCreate(db); } } 

下載JAR

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

放入libs

對專案右鍵>open modle setting見下圖2(已選擇Dependencies的結果)

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.[Android] AsyncTask - 非同步任務

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）{}。

陣列或物件的Value可以使用的資料型態包含：數字（int, float）、字串（string）、布林值（boolean）、陣列（Array）、物件（Object）或是空值（null）。

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實際範例