Android获取网络图片应用示例
1、养成好习惯,配置字符串资源文件 strings.xml
xml version="1.0" encoding="utf-8"?> <resources> <string name="app_name">网络图片查看器</string> <string name="action_settings">Settings</string> <string name="hello_world">Hello world!</string> <string name="imgpath">输入图片地址:</string> <string name="getBtn">获取图片</string> <string name="error">获取图片失败</string> </resources> <?xml version="1.0" encoding="utf-8"?> <resources> <string name="app_name">网络图片查看器</string> <string name="action_settings">Settings</string> <string name="hello_world">Hello world!</string> <string name="imgpath">输入图片地址:</string> <string name="getBtn">获取图片</string> <string name="error">获取图片失败</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>
、编写代码
这里为了方便看代码,都写在一个类里面了。
可以把里面的静态方法单独拆分出来,写在一个工具类中,结构更好。
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);// 超时时间5秒
conn.setRequestMethod("GET");
if (conn.getResponseCode() == 200) {
InputStream in = conn.getInputStream();
return read(in);
} else {
Log.d("tong.getImg", "服务器无响应");
}
return null;
}
/**
* 从一个输入流中读取数据,并返回
*
* @param in
* @return byte[] 数据
* @throws IOException
*/
public static byte[] read(InputStream in) throws IOException {
// 开辟一个内存的区域,以写入数据
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(); // 返回内存中的数据
}
}
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)补充:移动开发 , Android ,