如何在ImageView中使用URL引用的图像?
当前回答
试试这个方法,希望能帮助你解决问题。
这里我解释了如何使用“AndroidQuery”外部库以asyncTask方式从url/server加载图像,并将加载的图像缓存到设备文件或缓存区。
从这里下载“AndroidQuery”库 复制/粘贴这个jar到项目lib文件夹,并将这个库添加到项目构建路径 现在我展示演示如何使用它。
activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center">
<FrameLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="@+id/imageFromUrl"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="true"/>
<ProgressBar
android:id="@+id/pbrLoadImage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"/>
</FrameLayout>
</LinearLayout>
MainActivity.java
public class MainActivity extends Activity {
private AQuery aQuery;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
aQuery = new AQuery(this);
aQuery.id(R.id.imageFromUrl).progress(R.id.pbrLoadImage).image("http://itechthereforeiam.com/wp-content/uploads/2013/11/android-gone-packing.jpg",true,true);
}
}
Note : Here I just implemented common method to load image from url/server but you can use various types of method which can be provided by "AndroidQuery"to load your image easily.
其他回答
这是一个迟到的回复,正如上面所建议的AsyncTask将会和谷歌一点后,我发现了一个解决这个问题的方法。
Drawable Drawable = Drawable. createfromstream ((InputStream) new URL(" URL ").getContent(), "src");
imageView.setImageDrawable(可拉的);
这是完整的功能:
public void loadMapPreview () {
//start a background thread for networking
new Thread(new Runnable() {
public void run(){
try {
//download the drawable
final Drawable drawable = Drawable.createFromStream((InputStream) new URL("url").getContent(), "src");
//edit the view in the UI thread
imageView.post(new Runnable() {
public void run() {
imageView.setImageDrawable(drawable);
}
});
} catch (IOException e) {
e.printStackTrace();
}
}
}).start();
}
不要忘记在你的AndroidManifest.xml中添加以下权限来访问互联网。
< uses-permission android: name = " android.permission。互联网" / >
我自己也试过,还没有遇到任何问题。
来自Android开发者:
// show The Image in a ImageView
new DownloadImageTask((ImageView) findViewById(R.id.imageView1))
.execute("http://java.sogeti.nl/JavaBlog/wp-content/uploads/2009/04/android_icon_256.png");
public void onClick(View v) {
startActivity(new Intent(this, IndexActivity.class));
finish();
}
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
ImageView bmImage;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap mIcon11 = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return mIcon11;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
}
}
确保你在AndroidManifest.xml中设置了以下权限来访问互联网。
<uses-permission android:name="android.permission.INTERNET" />
如果你是在点击按钮的基础上加载图像,上面接受的答案是很棒的,但是如果你是在一个新的活动中做这件事,它会冻结UI一到两秒钟。环顾四周,我发现一个简单的asynctask消除了这个问题。
要使用asynctask,在activity的末尾添加这个类:
private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
ImageView bmImage;
public DownloadImageTask(ImageView bmImage) {
this.bmImage = bmImage;
}
protected Bitmap doInBackground(String... urls) {
String urldisplay = urls[0];
Bitmap mIcon11 = null;
try {
InputStream in = new java.net.URL(urldisplay).openStream();
mIcon11 = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return mIcon11;
}
protected void onPostExecute(Bitmap result) {
bmImage.setImageBitmap(result);
}
}
从你的onCreate()方法调用使用:
new DownloadImageTask((ImageView) findViewById(R.id.imageView1))
.execute(MY_URL_STRING);
结果是一个快速加载的活动和一个稍后根据用户的网络速度显示的imageview。
private Bitmap getImageBitmap(String url) {
Bitmap bm = null;
try {
URL aURL = new URL(url);
URLConnection conn = aURL.openConnection();
conn.connect();
InputStream is = conn.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
bm = BitmapFactory.decodeStream(bis);
bis.close();
is.close();
} catch (IOException e) {
Log.e(TAG, "Error getting bitmap", e);
}
return bm;
}
嗨,我有最简单的代码试试这个
public class ImageFromUrlExample extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ImageView imgView =(ImageView)findViewById(R.id.ImageView01);
Drawable drawable = LoadImageFromWebOperations("http://www.androidpeople.com/wp-content/uploads/2010/03/android.png");
imgView.setImageDrawable(drawable);
}
private Drawable LoadImageFromWebOperations(String url)
{
try{
InputStream is = (InputStream) new URL(url).getContent();
Drawable d = Drawable.createFromStream(is, "src name");
return d;
}catch (Exception e) {
System.out.println("Exc="+e);
return null;
}
}
}
main。xml
<LinearLayout
android:id="@+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<ImageView
android:id="@+id/ImageView01"
android:layout_height="wrap_content"
android:layout_width="wrap_content"/>
试试这个
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