</pre><p>布局文件activity_main.xml</p><p></p><pre name="code" class="html"><?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:id="@+id/activity_main" 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="com.dsy.selectpicture.MainActivity"> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="相机" android:id="@+id/xiangji"/> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="图库" android:layout_alignParentTop="true" android:layout_toRightOf="@+id/xiangji" android:layout_toEndOf="@+id/xiangji" android:layout_marginLeft="25dp" android:layout_marginStart="25dp" android:id="@+id/tuku"/> <ImageView android:layout_width="wrap_content" android:layout_marginTop="20dp" android:layout_height="wrap_content" android:src="@mipmap/ic_launcher" android:layout_centerHorizontal="true" android:id="@+id/iv" android:layout_below="@+id/xiangji"/> </RelativeLayout>
然后是MainActivity.java
import android.content.Intent; import android.graphics.Bitmap; import android.media.ThumbnailUtils; import android.net.Uri; import android.provider.MediaStore; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.ImageView; import java.io.File; import java.io.FileOutputStream; public class MainActivity extends AppCompatActivity { private final int SELECT_PICTURE = 1; // 从图库中选择图片 private final int SELECT_CAMER = 2; // 用相机拍摄照片 private static final String PicName = "pic.jpg"; private String PicPath; private ImageView iv; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); iv= (ImageView) findViewById(R.id.iv); PicPath = BitmapUtil.getImgCacheDir(this);//获取图片缓存路径 findViewById(R.id.xiangji).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { // 进入相机 Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); //设置照片保存路径 intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(PicPath, PicName))); startActivityForResult(intent, SELECT_CAMER); } }); findViewById(R.id.tuku).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { // 进入图库 // Intent intent = new Intent(Intent.ACTION_GET_CONTENT); // intent.addCategory(Intent.CATEGORY_OPENABLE); // intent.setType("image/*"); // startActivityForResult(intent, SELECT_PICTURE); Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI); intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,"image/*"); startActivityForResult(intent, SELECT_PICTURE); } }); } @Override protected void onActivityResult(final int requestCode, int resultCode, final Intent data) { if (resultCode == RESULT_OK) { //启动线程压缩图片 new Thread(new Runnable() { //开启线程保持文件到本地 @Override public void run() { Bitmap bitmap = null; //压缩图片 if (requestCode == SELECT_CAMER) { bitmap = BitmapUtil.compressImageFromFile(PicPath + "/"+PicName); } else if (requestCode == SELECT_PICTURE) { bitmap = BitmapUtil.compressImageFromUri(MainActivity.this, data.getData()); } //获取图片缩略图并显示 final Bitmap thumb=ThumbnailUtils.extractThumbnail(bitmap, 300, 300); runOnUiThread(new Runnable() { @Override public void run() { iv.setImageBitmap(thumb); } }); try { //保存压缩后的图片到本地 File f = new File(PicPath, PicName); f.createNewFile(); FileOutputStream fOut = new FileOutputStream(f); if (bitmap != null) { bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fOut); } fOut.flush(); fOut.close(); } catch (Exception e1) { e1.printStackTrace(); } } }).start(); } super.onActivityResult(requestCode, resultCode, data); } }
从图库选择的图片然后获取其绝对路径,这里踩了很多坑,多次测试找到了可行的解决工具类
import android.content.ContentUris; import android.content.Context; import android.database.Cursor; import android.net.Uri; import android.os.Build; import android.os.Environment; import android.provider.DocumentsContract; import android.provider.MediaStore; import android.text.TextUtils; import android.util.Log; public class PictureUtil { public static String getPicturePath(Context context, Uri uri) { String path = getPath(context, uri); if (TextUtils.isEmpty(path)) { path = selectImage(context, uri); } return path; } /** * 获取图库图片路径 */ public static String selectImage(Context context, Uri selectedImage) { if (selectedImage != null) { String uriStr = selectedImage.toString(); String path = uriStr.substring(10, uriStr.length()); if (path.startsWith("com.sec.android.gallery3d")) { Log.e("=====", "It's auto backup pic path:" + selectedImage.toString()); return null; } } String[] filePathColumn = {MediaStore.Images.Media.DATA}; Cursor cursor = context.getContentResolver().query(selectedImage, filePathColumn, null, null, null); String picturePath = null; if (cursor != null) { cursor.moveToFirst(); int columnIndex = cursor.getColumnIndex(filePathColumn[0]); picturePath = cursor.getString(columnIndex); cursor.close(); } return picturePath; } public static String getPath(final Context context, final Uri uri) { // DocumentProvider if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) { if (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 the remote address if (isGooglePhotosUri(uri)) return uri.getLastPathSegment(); 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 index = cursor.getColumnIndexOrThrow(column); return cursor.getString(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()); } /** * @param uri The Uri to check. * @return Whether the Uri authority is Google Photos. */ public static boolean isGooglePhotosUri(Uri uri) { return "com.google.android.apps.photos.content".equals(uri.getAuthority()); } }
最后是压缩图片的工具类
import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Matrix; import android.media.ExifInterface; import android.net.Uri; import android.os.Environment; import android.util.Log; import java.io.ByteArrayOutputStream; import java.io.IOException; public class BitmapUtil { public static String getImgCacheDir(Activity activity) { if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) { return activity.getExternalCacheDir().getAbsolutePath(); } else { return activity.getCacheDir().getAbsolutePath(); } } public static Bitmap compressImageFromFile(String srcPath) { BitmapFactory.Options newOpts = new BitmapFactory.Options(); newOpts.inJustDecodeBounds = true;//只读边,不读内容 Bitmap bitmap = BitmapFactory.decodeFile(srcPath, newOpts); newOpts.inJustDecodeBounds = false; int w = newOpts.outWidth; int h = newOpts.outHeight; int degree = getBitmapDegree(srcPath); float hh = 1000f;// float ww = 800f;// int be = 1; if (w > h && w > ww) { be = (int) (newOpts.outWidth / ww); } else if (w < h && h > hh) { be = (int) (newOpts.outHeight / hh); } if (be <= 0) be = 1; newOpts.inSampleSize = be;//设置采样率 newOpts.inPreferredConfig = Bitmap.Config.ARGB_8888;//该模式是默认的,可不设 newOpts.inPurgeable = true;// 同时设置才会有效 newOpts.inInputShareable = true;//。当系统内存不够时候图片自动被回收 bitmap = BitmapFactory.decodeFile(srcPath, newOpts); if (degree != 0) { bitmap = rotateBitmapByDegree(bitmap, degree); } // return compressImage(bitmap);//原来的方法调用了这个方法企图进行二次压缩 //其实是无效的,大家尽管尝试 ByteArrayOutputStream baos = new ByteArrayOutputStream(); bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);//这里100的话表示不压缩质量 long length = baos.toByteArray().length;//读出图片的kb大小 Log.d("====", "图片压缩前大小:" + baos.toByteArray().length / 1024f); if (length <= 2000000) { return bitmap;//如果图片本身的大小已经小于这个大小了,就没必要进行压缩 } int quality = 100; //压缩图片大小至 2000000b(2000000/1000/1024≈1.9M) 以下,可以根据需要调整大小 while (baos.toByteArray().length > 2000000) { quality = quality - 4;// 每次都减少4 baos.reset();// 重置baos即清空baos if (quality <= 0) { break; } bitmap.compress(Bitmap.CompressFormat.JPEG, quality, baos); Log.d("====", "图片压缩后大小:" + baos.toByteArray().length / 1024f); } bitmap = BitmapFactory.decodeByteArray(baos.toByteArray(), 0, baos.toByteArray().length, newOpts); return bitmap; } public static Bitmap compressImageFromUri(Context context, Uri uri) { return compressImageFromFile(PictureUtil.getPicturePath(context, uri)); } /** * 读取图片的旋转的角度 * * @param path 图片绝对路径 * @return 图片的旋转角度 */ public static int getBitmapDegree(String path) { int degree = 0; try { // 从指定路径下读取图片,并获取其EXIF信息 ExifInterface exifInterface = new ExifInterface(path); // 获取图片的旋转信息 int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL); switch (orientation) { case ExifInterface.ORIENTATION_ROTATE_90: degree = 90; break; case ExifInterface.ORIENTATION_ROTATE_180: degree = 180; break; case ExifInterface.ORIENTATION_ROTATE_270: degree = 270; break; default: } } catch (IOException e) { e.printStackTrace(); } return degree; } /** * 将图片按照某个角度进行旋转 * * @param bm 需要旋转的图片 * @param degree 旋转角度 * @return 旋转后的图片 */ private static Bitmap rotateBitmapByDegree(Bitmap bm, int degree) { Bitmap bitmap = null; // 根据旋转角度,生成旋转矩阵 Matrix matrix = new Matrix(); matrix.postRotate(degree); try { // 将原始图片按照旋转矩阵进行旋转,并得到新的图片 bitmap = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), matrix, true); } catch (OutOfMemoryError error) { Log.e("ESA", "rotateBitmapByDegree decodeFile OutOfMemoryError." + error.getMessage()); } if (bitmap == null) { bitmap = bm; } if (bm != bitmap) { bm.recycle(); } return bitmap; } }
已经有很多开源的网络请求框架支持了上传文件功能,推荐okhttp