Question

我希望在上传到服务器之前将图像大小缩小到kb，基本上是我的代码所做的，捕获图像将其存储在本地，然后将其上传到服务器。

只是想在本地存储在外部存储上时缩小图像大小。找到了一个很好的答案here 但问题是，我真的不知道如何使用下面的代码添加链接中的代码。 Android新手，请帮忙！

package com.project.camera;

import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

public class MainActivity extends Activity {

    // LogCat tag
    private static final String TAG = MainActivity.class.getSimpleName();


    // Camera activity request codes
    private static final int CAMERA_CAPTURE_IMAGE_REQUEST_CODE = 100;

    public static final int MEDIA_TYPE_IMAGE = 1;

    private Uri fileUri; // file url to store image


    private Button btnCapturePicture;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);




        btnCapturePicture = (Button) findViewById(R.id.btnCapturePicture);


        /**
         * Capture image button click event
         */
        btnCapturePicture.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // capture picture
                captureImage();
            }
        });




        // Checking camera availability
        if (!isDeviceSupportCamera()) {
            Toast.makeText(getApplicationContext(),
                    "Sorry! Your device doesn't support camera",
                    Toast.LENGTH_LONG).show();
            // will close the app if the device does't have camera
            finish();
        }
    }

    /**
     * Checking device has camera hardware or not
     * */
    private boolean isDeviceSupportCamera() {
        if (getApplicationContext().getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA)) {
            // this device has a camera
            return true;
        } else {
            // no camera on this device
            return false;
        }
    }

    /**
     * Launching camera app to capture image
     */
    private void captureImage() {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

        fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE);

        intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);

        // start the image capture Intent
        startActivityForResult(intent, CAMERA_CAPTURE_IMAGE_REQUEST_CODE);
    }


    /**
     * Here we store the file url as it will be null after returning from camera
     * app
     */
    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);

        // save file url in bundle as it will be null on screen orientation
        // changes
        outState.putParcelable("file_uri", fileUri);
    }

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);

        // get the file url
        fileUri = savedInstanceState.getParcelable("file_uri");
    }



    /**
     * Receiving activity result method will be called after closing the camera
     * */
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // if the result is capturing Image
        if (requestCode == CAMERA_CAPTURE_IMAGE_REQUEST_CODE) {
            if (resultCode == RESULT_OK) {

                // successfully captured the image
                // launching upload activity
                launchUploadActivity(true);


            } else if (resultCode == RESULT_CANCELED) {

                // user cancelled Image capture
                Toast.makeText(getApplicationContext(),
                        "User cancelled image capture", Toast.LENGTH_SHORT)
                        .show();

            } else {
                // failed to capture image
                Toast.makeText(getApplicationContext(),
                        "Sorry! Failed to capture image", Toast.LENGTH_SHORT)
                        .show();
            }

        }
    }

    private void launchUploadActivity(boolean isImage){
        Intent i = new Intent(MainActivity.this, UploadActivity.class);
        i.putExtra("filePath", fileUri.getPath());
        i.putExtra("isImage", isImage);
        startActivity(i);
    }

    /**
     * ------------ Helper Methods ---------------------- 
     * */

    /**
     * Creating file uri to store image
     */
    public Uri getOutputMediaFileUri(int type) {
        return Uri.fromFile(getOutputMediaFile(type));
    }

    /**
     * returning image
     */
    private static File getOutputMediaFile(int type) {

        // External sdcard location
        File mediaStorageDir = new File(
                Environment
                        .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
                Config.IMAGE_DIRECTORY_NAME);

        // Create the storage directory if it does not exist
        if (!mediaStorageDir.exists()) {
            if (!mediaStorageDir.mkdirs()) {
                Log.d(TAG, "Oops! Failed create "
                        + Config.IMAGE_DIRECTORY_NAME + " directory");
                return null;
            }
        }

        // Create a media file name
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
                Locale.getDefault()).format(new Date());
        File mediaFile;
        if (type == MEDIA_TYPE_IMAGE) {
            mediaFile = new File(mediaStorageDir.getPath() + File.separator
                    + "Selfie_" + timeStamp + ".jpg");
        }  else {
            return null;
        }

        return mediaFile;
    }
}

Answer 1

使用此，（我编辑了onPictureTaken（）函数以满足您的需要）

如果输入路径不存在且压缩时没有出错，则返回 false 。

public boolean resizeImage(String originalFilePath, String compressedFilePath) {
    InputStream in = null;
    try {
        in = new FileInputStream(originalFilePath);
    } catch (FileNotFoundException e) {
        Log.e("TAG","originalFilePath is not valid", e);
    }

    if (in == null) {
        return false;
    }

    BitmapFactory.Options options = new BitmapFactory.Options();
    Bitmap preview_bitmap = BitmapFactory.decodeStream(in, null, options);
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    preview_bitmap.compress(Bitmap.CompressFormat.JPEG, 60, stream);
    byte[] byteArray = stream.toByteArray();

    FileOutputStream outStream = null;
    try {
        outStream = new FileOutputStream(compressedFilePath);
        outStream.write(byteArray);
        outStream.close();
    } catch (Exception e) {
        Log.e("TAG","could not save", e);
    }

    return true;
}

在下载代码之前，在上传ANDROID之前将图像大小减小到KB

1 个答案: