編輯:關於Android編程
1、養成好習慣,配置字符串資源文件 strings.xml
xml version="1.0" encoding="utf-8"?> <resources> <string name="app_name">網絡圖片查看器</string> <string name="action_settings">Settings</string> <string name="hello_world">Hello world!</string> <string name="imgpath">輸入圖片地址:</string> <string name="getBtn">獲取圖片</string> <string name="error">獲取圖片失敗</string> </resources> <?xml version="1.0" encoding="utf-8"?> <resources> <string name="app_name">網絡圖片查看器</string> <string name="action_settings">Settings</string> <string name="hello_world">Hello world!</string> <string name="imgpath">輸入圖片地址:</string> <string name="getBtn">獲取圖片</string> <string name="error">獲取圖片失敗</string> </resources>
2、布局文件,使用垂直布局
LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context=".MainActivity" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/imgpath" /> <EditText android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/imgpathInput" android:text="http://avatar.csdn.net/B/E/7/1_gaotong2055.jpg" android:inputType="text" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/getBtn" android:id="@+id/getBtn" /> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/imgView" /> </LinearLayout> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context=".MainActivity" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/imgpath" /> <EditText android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/imgpathInput" android:text="http://avatar.csdn.net/B/E/7/1_gaotong2055.jpg" android:inputType="text" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/getBtn" android:id="@+id/getBtn" /> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/imgView" /> </LinearLayout>
、編寫代碼
這裡為了方便看代碼,都寫在一個類裡面了。
可以把裡面的靜態方法單獨拆分出來,寫在一個工具類中,結構更好。
public class MainActivity extends Activity implements OnClickListener { private EditText pathText; private ImageView imageView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); pathText = (EditText) this.findViewById(R.id.imgpathInput); imageView = (ImageView) this.findViewById(R.id.imgView); Button button = (Button) this.findViewById(R.id.getBtn); button.setOnClickListener(this); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return true; } @Override public void onClick(View v) { String path = pathText.getText().toString(); byte[] data = null; try { data = getImgData(path); } catch (Exception e) { e.printStackTrace(); Toast.makeText(this, R.string.error, 1).show(); } Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length); imageView.setImageBitmap(bitmap); } public static byte[] getImgData(String path) throws Exception { URL url = new URL(path); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setConnectTimeout(5000);// 超時時間5秒 conn.setRequestMethod("GET"); if (conn.getResponseCode() == 200) { InputStream in = conn.getInputStream(); return read(in); } else { Log.d("tong.getImg", "服務器無響應"); } return null; } /** * 從一個輸入流中讀取數據,並返回 * * @param in * @return byte[] 數據 * @throws IOException */ public static byte[] read(InputStream in) throws IOException { // 開辟一個內存的區域,以寫入數據 ByteArrayOutputStream outStream = new ByteArrayOutputStream(); byte[] buffer = new byte[10240]; int len = 0; while ((len = in.read(buffer)) != -1) { outStream.write(buffer, 0, len); } outStream.close(); return outStream.toByteArray(); // 返回內存中的數據 } } public class MainActivity extends Activity implements OnClickListener { private EditText pathText; private ImageView imageView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); pathText = (EditText) this.findViewById(R.id.imgpathInput); imageView = (ImageView) this.findViewById(R.id.imgView); Button button = (Button) this.findViewById(R.id.getBtn); button.setOnClickListener(this); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return true; } @Override public void onClick(View v) { String path = pathText.getText().toString(); byte[] data = null; try { data = getImgData(path); } catch (Exception e) { e.printStackTrace(); Toast.makeText(this, R.string.error, 1).show(); } Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length); imageView.setImageBitmap(bitmap); } public static byte[] getImgData(String path) throws Exception { URL url = new URL(path); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setConnectTimeout(5000);// 超時時間5秒 conn.setRequestMethod("GET"); if (conn.getResponseCode() == 200) { InputStream in = conn.getInputStream(); return read(in); } else { Log.d("tong.getImg", "服務器無響應"); } return null; } /** * 從一個輸入流中讀取數據,並返回 * * @param in * @return byte[] 數據 * @throws IOException */ public static byte[] read(InputStream in) throws IOException { // 開辟一個內存的區域,以寫入數據 ByteArrayOutputStream outStream = new ByteArrayOutputStream(); byte[] buffer = new byte[10240]; int len = 0; while ((len = in.read(buffer)) != -1) { outStream.write(buffer, 0, len); } outStream.close(); return outStream.toByteArray(); // 返回內存中的數據 } }
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