Question

我正在尝试使用简单的图像视图和下载应用程序，一切正常，直到我点击按钮下载应用程序，当我点击按钮时，我得到一个错误，说应用程序已关闭，因为它停止了工作。

package com.theappguruz.imagedownload;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.database.SQLException;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.view.Display;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.ImageView;

import com.theappguruz.R;

public class ImageViewAndDownload extends Activity implements OnClickListener {

    private Button btnImageDownload;
    private ProgressDialog pd;
    private ImageView viewDownloadImage;
    private Images imageId;
    private File folderName;
    private String imageName;

    private Handler handler = new Handler() {
        public void handleMessage(android.os.Message msg) {
            if (msg.what == 1) {
                if (pd != null) {
                    pd.dismiss();
                }
                Utils.showNetworkAlert(ImageViewAndDownload.this);
            } else if (msg.what == 2) {
                if (pd != null) {
                    pd.dismiss();
                }
                Utils.displayMessage("Image downloade succesfully",
                        ImageViewAndDownload.this);
                // Media scaning
                sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,
                        Uri.parse("file://"
                                + Environment.getExternalStorageDirectory())));

            } else if (msg.what == 3) {
                if (pd != null) {
                    pd.dismiss();
                }
                Utils.displayMessage("Image already downloaded ",
                        ImageViewAndDownload.this);
            } else if (msg.what == 4) {
                if (pd != null) {
                    pd.dismiss();
                }
                displayImageFromUrl((Bitmap) msg.obj);
            }

        }
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.imagedisplay);

        viewDownloadImage = (ImageView) findViewById(R.id.viewImage);
        btnImageDownload = (Button) findViewById(R.id.btnImageDownload);
        imageId = new Images();
        imageName = imageId.getImageId();
        LoadImageFromWeb(Constant.IMAGE_BASE_URL + File.separator + imageName);
        btnImageDownload.setOnClickListener(this);
    }

    public void onClick(View v) {
        if (v == btnImageDownload) {
            pd = ProgressDialog.show(ImageViewAndDownload.this, "",
                    "Downloading Image....", true, false);
            new Thread(new Runnable() {
                public void run() {
                    try {

                        String imageUrl = Constant.IMAGE_BASE_URL
                                + File.separator + imageName;
                        String isDownloded = downloadImage(imageUrl, imageName);
                        if (isDownloded.equalsIgnoreCase("complete")) {
                            handler.sendEmptyMessage(2);
                        } else if (isDownloded.equalsIgnoreCase("")) {
                            handler.sendEmptyMessage(3);
                        } else {
                            handler.sendEmptyMessage(1);
                        }
                    } catch (Exception e) {
                        e.printStackTrace();
                        handler.sendEmptyMessage(1);
                    }
                }
            }).start();

        }
    }

    // set display image to Imageview
    public void displayImageFromUrl(Bitmap obj) {
        viewDownloadImage.setImageBitmap(obj);
    }

    // image display from the webview
    private void LoadImageFromWeb(final String url1) {
        pd = ProgressDialog.show(ImageViewAndDownload.this, "",
                "Loading Image....", true, false);
        new Thread(new Runnable() {
            public void run() {
                try {

                    URL url = new URL(url1);
                    HttpURLConnection connection = (HttpURLConnection) url
                            .openConnection();

                    InputStream is = connection.getInputStream();

                    Options options = new BitmapFactory.Options();
                    options.inJustDecodeBounds = true;

                    BitmapFactory.decodeStream(is, null, options);

                    if (options.outWidth > 3000 || options.outHeight > 2000) {
                        options.inSampleSize = 4;
                    } else if (options.outWidth > 2000
                            || options.outHeight > 1500) {
                        options.inSampleSize = 3;
                    } else if (options.outWidth > 1000
                            || options.outHeight > 1000) {
                        options.inSampleSize = 2;
                    }
                    // Do the actual decoding
                    options.inJustDecodeBounds = false;

                    is.close();
                    is = getHTTPConnectionInputStream(url1);
                    Bitmap myBitmap = BitmapFactory.decodeStream(is, null,
                            options);
                    is.close();

                    if (myBitmap != null) {
                        Message msg = new Message();
                        msg.obj = myBitmap;
                        msg.what = 4;
                        handler.sendMessage(msg);
                    } else {
                        handler.sendEmptyMessage(1);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }

    public InputStream getHTTPConnectionInputStream(String url1) {
        URL url;
        InputStream is = null;
        try {
            url = new URL(url1);
            HttpURLConnection connection = (HttpURLConnection) url
                    .openConnection();
            is = connection.getInputStream();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return is;
    }

    // image download code
    public String downloadImage(String imageDownloadUrl, String imageName) {
        // create directory in SDCARD
        if (android.os.Environment.getExternalStorageState().equals(
                android.os.Environment.MEDIA_MOUNTED))
            folderName = new File(Constant.STORE_IN_FOLDER);
        else
            folderName = getFilesDir();

        if (!folderName.exists())
            folderName.mkdirs();

        String response = "";
        // create file name and file.
        File storeImageInSDCard = new File(folderName + File.separator
                + imageName);
        if (!(storeImageInSDCard.exists() && storeImageInSDCard.length() > 0)) {
            // start download image
            response = downloadFile(imageDownloadUrl, imageName,
                    folderName.toString());
        }
        return response;
    }

    // start download image
    public String downloadFile(final String url, final String name,
            String foldername) {

        File file;
        FileOutputStream os = null;
        Bitmap myBitmap;
        try {

            URL url1 = new URL(url.replaceAll(" ", "%20"));
            System.out.println("Image url :::" + url1);
            HttpURLConnection urlConnection = (HttpURLConnection) url1
                    .openConnection();
            urlConnection.setDoOutput(false);
            urlConnection.setRequestMethod("GET");
            urlConnection.connect();

            // here create a file which define folder name and image name with
            // extension.
            file = new File(foldername, name + ".jpg");
            InputStream inputStream = urlConnection.getInputStream();
            byte[] buffer = new byte[1024];
            int bufferLength = 0;
            os = new FileOutputStream(file);
            while ((bufferLength = inputStream.read(buffer)) > 0) {
                os.write(buffer, 0, bufferLength);
            }

            os.flush();
            os.close();

            // if image size is too large we can scale image than download.
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = true;
            myBitmap = BitmapFactory
                    .decodeFile(file.getAbsolutePath(), options);
            if (options.outWidth > 3000 || options.outHeight > 2000) {
                options.inSampleSize = 4;
            } else if (options.outWidth > 2000 || options.outHeight > 1500) {
                options.inSampleSize = 3;
            } else if (options.outWidth > 1000 || options.outHeight > 1000) {
                options.inSampleSize = 2;
            }
            options.inJustDecodeBounds = false;
            myBitmap = BitmapFactory
                    .decodeFile(file.getAbsolutePath(), options);

            os = new FileOutputStream(file);
            myBitmap.compress(CompressFormat.JPEG, 90, os);
            os.flush();
            os.close();
            myBitmap.recycle();

            return "complete";
        } catch (SQLException e) {
            e.printStackTrace();
            return "error";
        } catch (Exception e) {
            e.printStackTrace();
            return "error";
        }

    }
}

Link to the LogCat enter image description here

Answer 1

你有：

sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,
                    Uri.parse("file://"
                            + Environment.getExternalStorageDirectory())));

首先，这绝不适合使用。

其次，它现在被阻止，因为它从来都不适合使用，现在谷歌正在新版本的Android上停止它。

正确的方法是使用MediaScannerConnection及其scanFile()方法，或者ACTION_MEDIA_SCANNER_SCAN_FILE。

将图像保存到SD卡时应用程序崩溃

1 个答案: