我有一个图片的URL,想要在ImageView中显示这张图片,但我无法做到。
如何实现这个功能呢?
我有一个图片的URL,想要在ImageView中显示这张图片,但我无法做到。
如何实现这个功能呢?
如果您是基于点击按钮加载图像,则上面的被接受答案非常好,但是如果您在新活动中执行此操作,则会使UI冻结一两秒钟。我发现使用简单的asynctask可以消除这个问题。
要使用asynctask,请将该类添加到您的活动末尾:
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);
}
}
并在您的onCreate()方法中使用以下代码进行调用:
new DownloadImageTask((ImageView) findViewById(R.id.imageView1))
.execute(MY_URL_STRING);
不要忘记在你的清单文件中添加以下权限。<uses-permission android:name="android.permission.INTERNET"/>
对我来说很好用。:)
URL url = new URL("http://image10.bizrate-images.com/resize?sq=60&uid=2216744464");
Bitmap bmp = BitmapFactory.decodeStream(url.openConnection().getInputStream());
imageView.setImageBitmap(bmp);
试试用 picasso
优雅地完成一句话。
Picasso.with(context)
.load(ImageURL)
.resize(width,height).into(imageView);
教程: https://youtu.be/DxRqxsEPc2s
(注意:最新版本中Picasso.with()
已更名为Picasso.get()
)
有两种方式:
1)使用Glide库 这是从URL加载图像的最佳方式,因为当您尝试第二次显示相同的URL时,它将从缓存中显示,从而提高应用程序性能。
Glide.with(context).load("YourUrl").into(imageView);
依赖项:implementation 'com.github.bumptech.glide:glide:4.10.0'
2)使用流:在这里,您想从URL图像创建位图
URL url = new URL("YourUrl");
Bitmap bitmap = BitmapFactory.decodeStream(url.openConnection().getInputStream());
imageView.setImageBitmap(bitmap);
Picasso.with(context)
.load(ImageURL)
.resize(width,height).noFade().into(imageView);
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;
import android.widget.Toast;
public class imageDownload {
Bitmap bmImg;
void downloadfile(String fileurl,ImageView img)
{
URL myfileurl =null;
try
{
myfileurl= new URL(fileurl);
}
catch (MalformedURLException e)
{
e.printStackTrace();
}
try
{
HttpURLConnection conn= (HttpURLConnection)myfileurl.openConnection();
conn.setDoInput(true);
conn.connect();
int length = conn.getContentLength();
int[] bitmapData =new int[length];
byte[] bitmapData2 =new byte[length];
InputStream is = conn.getInputStream();
BitmapFactory.Options options = new BitmapFactory.Options();
bmImg = BitmapFactory.decodeStream(is,null,options);
img.setImageBitmap(bmImg);
//dialog.dismiss();
}
catch(IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
// Toast.makeText(PhotoRating.this, "Connection Problem. Try Again.", Toast.LENGTH_SHORT).show();
}
}
}
在你的活动中,取出ImageView并设置资源:imageDownload(url, yourImageview);
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.ProgressBar;
import java.io.InputStream;
/**
* Created by Sergey Shustikov (pandarium.shustikov@gmail.com) at 2015.
*/
public class DownloadImageTask extends AsyncTask<String, Void, Bitmap>
{
public static final int ANIMATION_DURATION = 250;
private final ImageView mDestination, mFakeForError;
private final String mUrl;
private final ProgressBar mProgressBar;
private Animation.AnimationListener mOutAnimationListener = new Animation.AnimationListener()
{
@Override
public void onAnimationStart(Animation animation)
{
}
@Override
public void onAnimationEnd(Animation animation)
{
mProgressBar.setVisibility(View.GONE);
}
@Override
public void onAnimationRepeat(Animation animation)
{
}
};
private Animation.AnimationListener mInAnimationListener = new Animation.AnimationListener()
{
@Override
public void onAnimationStart(Animation animation)
{
if (isBitmapSet)
mDestination.setVisibility(View.VISIBLE);
else
mFakeForError.setVisibility(View.VISIBLE);
}
@Override
public void onAnimationEnd(Animation animation)
{
}
@Override
public void onAnimationRepeat(Animation animation)
{
}
};
private boolean isBitmapSet;
public DownloadImageTask(Context context, ImageView destination, String url)
{
mDestination = destination;
mUrl = url;
ViewGroup parent = (ViewGroup) destination.getParent();
mFakeForError = new ImageView(context);
destination.setVisibility(View.GONE);
FrameLayout layout = new FrameLayout(context);
mProgressBar = new ProgressBar(context);
FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
params.gravity = Gravity.CENTER;
mProgressBar.setLayoutParams(params);
FrameLayout.LayoutParams copy = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
copy.gravity = Gravity.CENTER;
copy.width = dpToPx(48);
copy.height = dpToPx(48);
mFakeForError.setLayoutParams(copy);
mFakeForError.setVisibility(View.GONE);
mFakeForError.setImageResource(android.R.drawable.ic_menu_close_clear_cancel);
layout.addView(mProgressBar);
layout.addView(mFakeForError);
mProgressBar.setIndeterminate(true);
parent.addView(layout, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
}
protected Bitmap doInBackground(String... urls)
{
String urlDisplay = mUrl;
Bitmap bitmap = null;
try {
InputStream in = new java.net.URL(urlDisplay).openStream();
bitmap = BitmapFactory.decodeStream(in);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return bitmap;
}
protected void onPostExecute(Bitmap result)
{
AlphaAnimation in = new AlphaAnimation(0f, 1f);
AlphaAnimation out = new AlphaAnimation(1f, 0f);
in.setDuration(ANIMATION_DURATION * 2);
out.setDuration(ANIMATION_DURATION);
out.setAnimationListener(mOutAnimationListener);
in.setAnimationListener(mInAnimationListener);
in.setStartOffset(ANIMATION_DURATION);
if (result != null) {
mDestination.setImageBitmap(result);
isBitmapSet = true;
mDestination.startAnimation(in);
} else {
mFakeForError.startAnimation(in);
}
mProgressBar.startAnimation(out);
}
public int dpToPx(int dp) {
DisplayMetrics displayMetrics = mDestination.getContext().getResources().getDisplayMetrics();
int px = Math.round(dp * (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));
return px;
}
}
<uses-permission android:name="android.permission.INTERNET"/>
new DownloadImageTask(context, imageViewToLoad, urlToImage).execute();
<uses-permission android:name="android.permission.INTERNET" />
public static Bitmap getBitmapFromURL(String src) {
try {
Log.e("src", src);
URL url = new URL(src);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
Log.e("Bitmap", "returned");
return myBitmap;
} catch (IOException e) {
e.printStackTrace();
Log.e("Exception", e.getMessage());
return null;
}
}
ImageView img_add = (ImageView) findViewById(R.id.img_add);
img_add.setImageBitmap(getBitmapFromURL("http://www.deepanelango.me/wpcontent/uploads/2017/06/noyyal1.jpg"));
这对我来说可行。
public static Void downloadfile(String fileurl, ImageView img) {
Bitmap bmImg = null;
URL myfileurl = null;
try {
myfileurl = new URL(fileurl);
} catch (MalformedURLException e) {
e.printStackTrace();
}
try {
HttpURLConnection conn = (HttpURLConnection) myfileurl.openConnection();
conn.setDoInput(true);
conn.connect();
int length = conn.getContentLength();
if (length > 0) {
int[] bitmapData = new int[length];
byte[] bitmapData2 = new byte[length];
InputStream is = conn.getInputStream();
bmImg = BitmapFactory.decodeStream(is);
img.setImageBitmap(bmImg);
}
} catch (IOException e) {
e.printStackTrace();
}
}