我正在尝试制作一个有2个按钮的应用。使用OPEN CAMERA我们使用相机意图拍摄照片并将其转换为base64编码并将其存储在服务器上。 使用GET PICTURE，我们尝试从服务器获取图片并使用universalimageloader将其显示在imageview中。 第一部分，即存储图片是完美的工作，但我无法下载图像并在imageview中显示它。
package backbenchersbeta.task;
import android.app.ProgressDialog;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import android.preference.PreferenceActivity;
import android.util.Base64;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.View;
import android.widget.ImageView;
import android.widget.Toast;
import com.loopj.android.http.AsyncHttpClient;
import com.loopj.android.http.AsyncHttpResponseHandler;
import com.loopj.android.http.RequestParams;
import com.nostra13.universalimageloader.cache.disc.naming.Md5FileNameGenerator;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.assist.QueueProcessingType;
import com.nostra13.universalimageloader.cache.memory.impl.WeakMemoryCache;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.assist.ImageScaleType;
import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer;
import com.nostra13.universalimageloader.core.imageaware.ImageAware;
import com.nostra13.universalimageloader.core.imageaware.ImageViewAware;
import cz.msebera.android.httpclient.Header;
public class MainActivity extends Activity {
static int TAKE_PIC =1;
Uri outPutfileUri;
RequestParams params = new RequestParams();
ProgressDialog prgDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder()
.cacheOnDisc(true).cacheInMemory(true)
.imageScaleType(ImageScaleType.EXACTLY)
.displayer(new FadeInBitmapDisplayer(300)).build();
ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(
getApplicationContext())
.defaultDisplayImageOptions(defaultOptions)
.memoryCache(new WeakMemoryCache())
.discCacheSize(100 * 1024 * 1024).build();
ImageLoader.getInstance().init(config);
prgDialog = new ProgressDialog(this);
// Set Cancelable as False
prgDialog.setCancelable(false);
}
public void CameraClick(View v) {
Intent intent= new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
File f= new File(android.os.Environment.getExternalStorageDirectory(), "temp.jpg");
outPutfileUri = Uri.fromFile(f);
intent.putExtra(MediaStore.EXTRA_OUTPUT, outPutfileUri);
params.put("filename", "temp.jpg");
Toast.makeText(getApplicationContext(), "Taking pic",
Toast.LENGTH_LONG).show();
startActivityForResult(intent, TAKE_PIC);
}
@Override
protected void onActivityResult(int requestCode, int resultCode,Intent data)
{
if (requestCode == TAKE_PIC && resultCode==RESULT_OK){
File f = new File(Environment.getExternalStorageDirectory().toString());
for (File temp : f.listFiles()) {
if (temp.getName().equals("temp.jpg")) {
f = temp;
break;
}
}
try {
Bitmap bitmap;
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
Toast.makeText(this, outPutfileUri.toString(),Toast.LENGTH_LONG).show();
prgDialog.setMessage("Converting Image to Binary Data");
prgDialog.show();
bitmap = BitmapFactory.decodeFile(f.getAbsolutePath(),bitmapOptions);
Toast.makeText(getApplicationContext(), "Started converting",
Toast.LENGTH_LONG).show();
ByteArrayOutputStream bao = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bao);
byte[] ba = bao.toByteArray();
String ba1=Base64.encodeToString(ba,Base64.DEFAULT);
prgDialog.setMessage("Calling Upload");
params.put("image", ba1);
triggerImageUpload();} catch (Exception e) {
e.printStackTrace();
}
}
}
public void triggerImageUpload() {
makeHTTPCall();
}
public void makeHTTPCall() {
prgDialog.setMessage("Invoking Php");
AsyncHttpClient client = new AsyncHttpClient();
// Don't forget to change the IP address to your LAN address. Port no as well.
client.post("http://192.168.43.145:80/imgupload/upload_image.php",
params, new AsyncHttpResponseHandler() {
// When the response returned by REST has Http
// response code '200'
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] response) {
prgDialog.hide();
Toast.makeText(getApplicationContext(), "Done",
Toast.LENGTH_LONG).show();
}
// When the response returned by REST has Http
// response code other than '200' such as '404',
// '500' or '403' etc
@Override
public void onFailure(int statusCode, Header[] headers, byte[] errorResponse, Throwable e) {
prgDialog.hide();
if (statusCode == 404) {
Toast.makeText(getApplicationContext(),
"Requested resource not found",
Toast.LENGTH_LONG).show();
}
// When Http response code is '500'
else if (statusCode == 500) {
Toast.makeText(getApplicationContext(),
"Something went wrong at server end",
Toast.LENGTH_LONG).show();
}
// When Http response code other than 404, 500
else {
Toast.makeText(
getApplicationContext(),
"Error Occured n Most Common Error: n1. Device not connected to Internetn2. Web App is not deployed in App servern3. App server is not running HTTP Status code : "
+ statusCode, Toast.LENGTH_LONG)
.show();
}
}
});
}
public void GetPicture(View v) {
String url="http://192.168.43.145:80/imgupload/uploadedimages/temp.jpg";
Toast.makeText(getApplicationContext(), "Inside getpic",
Toast.LENGTH_LONG).show();
ImageLoader imageLoader = ImageLoader.getInstance();
DisplayImageOptions options = new DisplayImageOptions.Builder().cacheInMemory(true)
.cacheOnDisc(true).resetViewBeforeLoading(true)
.build();
ImageView img = (ImageView) findViewById(R.id.imageView);
ImageAware imageAware = new ImageViewAware(img, false);
imageLoader.displayImage(url,img,options);
/*Bitmap bitmap = DownloadImage(
"http://192.168.43.145:80/imgupload/uploadedimages/temp.jpg");
ImageView img = (ImageView) findViewById(R.id.imageView);
img.setImageBitmap(bitmap);*/
}
private InputStream OpenHttpConnection(String urlString)
throws IOException
{Toast.makeText(getApplicationContext(), "Inside imputstream",
Toast.LENGTH_LONG).show();
InputStream in = null;
int response = -1;
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
if (!(conn instanceof HttpURLConnection))
throw new IOException("Not an HTTP connection");
try{
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
Toast.makeText(getApplicationContext(), "Inside tryblock1",
Toast.LENGTH_LONG).show();
httpConn.setRequestMethod("GET");
Toast.makeText(getApplicationContext(), "Inside tryblock2",
Toast.LENGTH_LONG).show();
httpConn.connect();
Toast.makeText(getApplicationContext(), "Inside tryblock3",
Toast.LENGTH_LONG).show();
response = httpConn.getResponseCode();
if (response == HttpURLConnection.HTTP_OK) {
in = httpConn.getInputStream();
}
}
catch (Exception ex)
{
throw new IOException("Error connecting");
}
return in;
}
public static void initImageLoader(Context context) {
// ImageLoaderConfiguration.createDefault(this);
ImageLoaderConfiguration.Builder config = new ImageLoaderConfiguration.Builder(context);
config.threadPriority(Thread.NORM_PRIORITY - 2);
config.denyCacheImageMultipleSizesInMemory();
config.diskCacheFileNameGenerator(new Md5FileNameGenerator());
config.tasksProcessingOrder(QueueProcessingType.LIFO);
config.writeDebugLogs(); // Remove for release app
// Initialize ImageLoader with configuration.
ImageLoader.getInstance().init(config.build());
}
private Bitmap DownloadImage(String URL)
{Toast.makeText(getApplicationContext(), "Inside dowmloadimage",
Toast.LENGTH_LONG).show();
Bitmap bitmap = null;
InputStream in = null;
try {
in = OpenHttpConnection(URL);
bitmap = BitmapFactory.decodeStream(in);
in.close();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
return bitmap;
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
// Dismiss the progress bar when application is closed
if (prgDialog != null) {
prgDialog.dismiss();
}
}
}
布局文件是
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
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="backbenchersbeta.task.MainActivity">
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:gravity="center"
android:layout_gravity="center"
android:layout_marginTop="100dp"
android:text="Open Camera"
android:onClick="CameraClick"
android:background="#0054a6"
android:padding="15dp"
android:textColor="#ffffff"/>
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:layout_gravity="center"
android:text="Get Picture"
android:onClick="GetPicture"
android:background="#0054a6"
android:padding="15dp"
android:textColor="#ffffff"
android:layout_alignTop="@+id/button1"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView"
android:layout_below="@+id/button1"
android:layout_centerHorizontal="true"
android:layout_marginTop="106dp" />
</RelativeLayout>
问题在于，虽然图像显示一次，但在拍摄另一张照片后，即使点击拍照后也不会改变。
答案 0 :(得分：0)
在GetPicture中，我进行了以下更改
DisplayImageOptions options = new DisplayImageOptions.Builder().cacheInMemory(false) .cacheOnDisc(false).resetViewBeforeLoading(true).build();
出现问题是因为正在显示存储在缓存中的图像。