我直接從專案copy過來了專案程式碼段落,有些可以直接不要,我會加註釋的

1.先定義一個相機或者相簿的標識碼

    private int REQUEST_CODE_PICK = 101;
    private int REQUEST_CODE_CAMERA = 102;

2.然後我們就要跳轉了,因為我是Dialog彈窗所以這邊會有個postion判斷點選的是否相機或者相簿 
   

                   if (position == 0) {//開啟相簿
                        Intent intent = new Intent();
                        intent.addCategory(Intent.CATEGORY_OPENABLE);
                        intent.setType("image/*");
                        if (Build.VERSION.SDK_INT < 19) {
                            intent.setAction(Intent.ACTION_GET_CONTENT);
                        } else {
                            intent.setAction(Intent.ACTION_OPEN_DOCUMENT);
                        }
                        startActivityForResult(intent, REQUEST_CODE_PICK);
                    } else if (position == 1) {//開啟相機
                        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                        //下面這句指定呼叫相機拍照後的照片儲存的路徑
                        intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri
                        .fromFile(new                     File(Environment.getExternalStorageDirectory().getPath()+"/"+"table.jpg")));

                        startActivityForResult(intent, REQUEST_CODE_CAMERA);
                    }
 

3.下面我們要寫一下相機或者相簿的回撥

    //相機相簿的回撥
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_CODE_PICK && resultCode == RESULT_OK) {
            String path = GetPathFromUri.getPath(UploadSkillCertifyActivity.this, data.getData());
            //imgPath就是壓縮後的圖片
            String imgPath = BitmapUtil.compressImageUpload(path);
        } else if (requestCode == REQUEST_CODE_CAMERA && resultCode == RESULT_OK) {
            String cameraPath = Environment
                    .getExternalStorageDirectory().getPath()+"/"+"table.jpg";
            //imgPath就是壓縮後的圖片
            String imgPath = BitmapUtil.compressImageUpload(path);
        }
    }
 

4.寫一下GetPathFromUri的獲取路徑工具類

public class GetPathFromUri {

    @SuppressLint("NewApi")
    public static String getPath(final Context context, final Uri uri) {

        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

        // DocumentProvider
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }

                // TODO handle non-primary volumes
            }
            // DownloadsProvider
            else if (isDownloadsDocument(uri)) {

                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(
                        Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }

                final String selection = "_id=?";
                final String[] selectionArgs = new String[]{split[1]};

                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        }
        // MediaStore (and general)
        else if ("content".equalsIgnoreCase(uri.getScheme())) {
            return getDataColumn(context, uri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }

        return null;
    }

    /**
     * Get the value of the data column for this Uri. This is useful for
     * MediaStore Uris, and other file-based ContentProviders.
     *
     * @param context       The context.
     * @param uri           The Uri to query.
     * @param selection     (Optional) Filter used in the query.
     * @param selectionArgs (Optional) Selection arguments used in the query.
     * @return The value of the _data column, which is typically a file path.
     */
    public static String getDataColumn(Context context, Uri uri, String selection,
                                       String[] selectionArgs) {

        Cursor cursor = null;
        final String column = "_data";
        final String[] projection = {column};

        try {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
                    null);
            if (cursor != null && cursor.moveToFirst()) {
                final int column_index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(column_index);
            }
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return null;
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is ExternalStorageProvider.
     */
    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is DownloadsProvider.
     */
    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is MediaProvider.
     */
    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }
}
 

5.再寫一下BitmapUtil對圖片的壓縮工具類

public class BitmapUtil {

    /**
     * 質量壓縮方法
     *
     * @param image
     * @return
     */
    private static Bitmap compressImage(Bitmap image) {

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        image.compress(Bitmap.CompressFormat.JPEG, 100, baos);
        int options = 100;
        while (baos.toByteArray().length / 1024 > 100) {
            baos.reset();
            image.compress(Bitmap.CompressFormat.JPEG, options, baos);
            options -= 10;
        }
        ByteArrayInputStream isBm = new ByteArrayInputStream(baos.toByteArray());
        Bitmap bitmap = BitmapFactory.decodeStream(isBm, null, null);
        return bitmap;
    }

    /**
     * 圖片按比例大小壓縮方法（根據路徑獲取圖片並壓縮）
     *
     * @param srcPath
     * @return
     */
    private static Bitmap getImage(String srcPath) {
        BitmapFactory.Options newOpts = new BitmapFactory.Options();
        newOpts.inJustDecodeBounds = true;
        Bitmap bitmap = BitmapFactory.decodeFile(srcPath, newOpts);// 此時返回bm為空

        newOpts.inJustDecodeBounds = false;
        int w = newOpts.outWidth;
        int h = newOpts.outHeight;
        // 現在主流手機比較多是800*480解析度，所以高和寬我們設定為
        float hh = 800f;// 這裡設定高度為800f
        float ww = 480f;// 這裡設定寬度為480f
        // 縮放比。由於是固定比例縮放，只用高或者寬其中一個數據進行計算即可
        int be = 1;// be=1表示不縮放
        if (w > h && w > ww) {// 如果寬度大的話根據寬度固定大小縮放
            be = (int) (newOpts.outWidth / ww);
        } else if (w < h && h > hh) {// 如果高度高的話根據寬度固定大小縮放
            be = (int) (newOpts.outHeight / hh);
        }
        if (be <= 0)
            be = 1;
        newOpts.inSampleSize = be;// 設定縮放比例
        // 重新讀入圖片，注意此時已經把options.inJustDecodeBounds 設回false了
        bitmap = BitmapFactory.decodeFile(srcPath, newOpts);
        return compressImage(bitmap);// 壓縮好比例大小後再進行質量壓縮
    }

    /**
     * 將壓縮的bitmap儲存到SDCard卡臨時資料夾，用於上傳
     *
     * @param filename
     * @param bit
     * @return
     */
    private static String saveMyBitmap(String filename, Bitmap bit) {
        String baseDir = Environment.getExternalStorageDirectory().getAbsolutePath()+"/laopai/";
        String filePath = baseDir + filename;
        File dir = new File(baseDir);
        if (!dir.exists()) {
            dir.mkdir();
        }

        File f = new File(filePath);
        try {
            f.createNewFile();
            FileOutputStream fOut = null;
            fOut = new FileOutputStream(f);
            bit.compress(Bitmap.CompressFormat.PNG, 100, fOut);
            fOut.flush();
            fOut.close();
        } catch (IOException e1) {
            e1.printStackTrace();
        }

        return filePath;
    }

    /**
     * 壓縮上傳路徑
     * @param path
     * @return
     */
    public static String compressImageUpload(String path) {
        String filename = path.substring(path.lastIndexOf("/") + 1);
        Bitmap image = getImage(path);
        return saveMyBitmap(filename, image);
    }


    /**
     * 清除快取檔案
     */
    public static void deleteCacheFile(){
        File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/laopai/");
        RecursionDeleteFile(file);
    }
    /**
     * 遞迴刪除
     */
    private static void RecursionDeleteFile(File file){
        if(file.isFile()){
            file.delete();
            return;
        }
        if(file.isDirectory()){
            File[] childFile = file.listFiles();
            if(childFile == null || childFile.length == 0){
                file.delete();
                return;
            }
            for(File f : childFile){
                RecursionDeleteFile(f);
            }
            file.delete();
        }
    }
}

6.好了到這裡就完成了,有什麼不懂的可以問我