Android实现选择相册图片并显示功能
人气:0需求描述: 选择手机相册中的一张图片,并通过ImageView展示出来
参考博文: android打开手机相册获取真正的图片路径
效果展示:
示例代码:
MainActivity
package com.example.www.mutilmedia; import android.Manifest; import android.app.Activity; import android.content.Intent; import android.content.pm.PackageManager; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.Build; import android.os.Bundle; import android.support.annotation.NonNull; import android.support.v4.app.ActivityCompat; import android.support.v7.app.AppCompatActivity; import android.util.Log; import android.view.View; import android.widget.ImageView; import android.widget.Toast; import java.util.Arrays; public class MainActivity extends AppCompatActivity { String[] mPermissionList = new String[]{ Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE}; public static final int REQUEST_PICK_IMAGE = 11101; private ImageView mShowImg; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mShowImg = (ImageView) findViewById(R.id.imageView); } @Override public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { super.onRequestPermissionsResult(requestCode, permissions, grantResults); switch (requestCode) { case 100: boolean writeExternalStorage = grantResults[0] == PackageManager.PERMISSION_GRANTED; boolean readExternalStorage = grantResults[1] == PackageManager.PERMISSION_GRANTED; Log.e("MainActivity", Arrays.toString(grantResults)); if (grantResults.length > 0 && writeExternalStorage && readExternalStorage) { getImage(); } else { Toast.makeText(this, "请设置必要权限", Toast.LENGTH_SHORT).show(); } break; } } private void getImage() { if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) { startActivityForResult(new Intent(Intent.ACTION_GET_CONTENT).setType("image/*"), REQUEST_PICK_IMAGE); } else { Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT); intent.addCategory(Intent.CATEGORY_OPENABLE); intent.setType("image/*"); startActivityForResult(intent, REQUEST_PICK_IMAGE); } } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); if (resultCode == Activity.RESULT_OK) { switch (requestCode) { case REQUEST_PICK_IMAGE: if (data != null) { String realPathFromUri = RealPathFromUriUtils.getRealPathFromUri(this, data.getData()); Log.e("MainActivity", realPathFromUri); showImg(realPathFromUri); } else { Toast.makeText(this, "图片损坏,请重新选择", Toast.LENGTH_SHORT).show(); } break; } } } public void openCamera(View view) { ActivityCompat.requestPermissions(MainActivity.this, mPermissionList, 100); } public void showImg(String path){ Bitmap bitmap = BitmapFactory.decodeFile(path); mShowImg.setImageBitmap(bitmap); } }
RealPathFromUriUtils
package com.example.www.mutilmedia; import android.annotation.SuppressLint; import android.content.ContentUris; import android.content.Context; import android.database.Cursor; import android.net.Uri; import android.os.Build; import android.provider.DocumentsContract; import android.provider.MediaStore; public class RealPathFromUriUtils { /** * 根据Uri获取图片的绝对路径 * * @param context 上下文对象 * @param uri 图片的Uri * @return 如果Uri对应的图片存在, 那么返回该图片的绝对路径, 否则返回null */ public static String getRealPathFromUri(Context context, Uri uri) { int sdkVersion = Build.VERSION.SDK_INT; if (sdkVersion >= 19) { // api >= 19 return getRealPathFromUriAboveApi19(context, uri); } else { // api < 19 return getRealPathFromUriBelowAPI19(context, uri); } } /** * 适配api19以下(不包括api19),根据uri获取图片的绝对路径 * * @param context 上下文对象 * @param uri 图片的Uri * @return 如果Uri对应的图片存在, 那么返回该图片的绝对路径, 否则返回null */ private static String getRealPathFromUriBelowAPI19(Context context, Uri uri) { return getDataColumn(context, uri, null, null); } /** * 适配api19及以上,根据uri获取图片的绝对路径 * * @param context 上下文对象 * @param uri 图片的Uri * @return 如果Uri对应的图片存在, 那么返回该图片的绝对路径, 否则返回null */ @SuppressLint("NewApi") private static String getRealPathFromUriAboveApi19(Context context, Uri uri) { String filePath = null; if (DocumentsContract.isDocumentUri(context, uri)) { // 如果是document类型的 uri, 则通过document id来进行处理 String documentId = DocumentsContract.getDocumentId(uri); if (isMediaDocument(uri)) { // MediaProvider // 使用':'分割 String id = documentId.split(":")[1]; String selection = MediaStore.Images.Media._ID + "=?"; String[] selectionArgs = {id}; filePath = getDataColumn(context, MediaStore.Images.Media.EXTERNAL_CONTENT_URI, selection, selectionArgs); } else if (isDownloadsDocument(uri)) { // DownloadsProvider Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(documentId)); filePath = getDataColumn(context, contentUri, null, null); } } else if ("content".equalsIgnoreCase(uri.getScheme())) { // 如果是 content 类型的 Uri filePath = getDataColumn(context, uri, null, null); } else if ("file".equals(uri.getScheme())) { // 如果是 file 类型的 Uri,直接获取图片对应的路径 filePath = uri.getPath(); } return filePath; } /** * 获取数据库表中的 _data 列,即返回Uri对应的文件路径 * * @return */ private static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) { String path = null; String[] projection = new String[]{MediaStore.Images.Media.DATA}; Cursor cursor = null; try { cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null); if (cursor != null && cursor.moveToFirst()) { int columnIndex = cursor.getColumnIndexOrThrow(projection[0]); path = cursor.getString(columnIndex); } } catch (Exception e) { if (cursor != null) { cursor.close(); } } return path; } /** * @param uri the Uri to check * @return Whether the Uri authority is MediaProvider */ private 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 DownloadsProvider */ private static boolean isDownloadsDocument(Uri uri) { return "com.android.providers.downloads.documents".equals(uri.getAuthority()); } }
activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <ImageView android:id="@+id/imageView" android:layout_width="0dp" android:layout_height="0dp" android:layout_marginStart="8dp" android:layout_marginTop="8dp" android:layout_marginEnd="8dp" android:layout_marginBottom="8dp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toBottomOf="@+id/button3" app:srcCompat="@android:color/white" /> <Button android:id="@+id/button3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginStart="8dp" android:layout_marginTop="16dp" android:layout_marginEnd="8dp" android:onClick="openCamera" android:text="camera" app:layout_constraintEnd_toEndOf="parent" app:layout_constraintHorizontal_bias="0.048" app:layout_constraintStart_toStartOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout>
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.www.mutilmedia"> <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /> <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
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