我试图从我的应用程序中打开画廊内置应用程序中的图像/图片。
我有一个图片的URI(图片位于SD卡上)。
你有什么建议吗?
当前回答
这是我的例子，可能不完全是你的情况。
假设你从你的API提供者获得base64格式，给它一个文件名和文件扩展名，将它保存到文件系统中的某个位置。
public static void shownInBuiltInGallery(final Context ctx, String strBase64Image, final String strFileName, final String strFileExtension){
new AsyncTask<String, String, File>() {
@Override
protected File doInBackground(String... strBase64Image) {
Bitmap bmpImage = convertBase64StringToBitmap(strBase64Image[0], Base64.NO_WRAP);
if(bmpImage == null) {
cancel(true);
return null;
}
byte[] byImage = null;
if(strFileExtension.compareToIgnoreCase(FILE_EXTENSION_JPG) == 0) {
byImage = convertToJpgByte(bmpImage); // convert bitmap to binary for latter use
} else if(strFileExtension.compareToIgnoreCase(FILE_EXTENSION_PNG) == 0){
byImage = convertToPngByte(bmpImage); // convert bitmap to binary for latter use
} else if(strFileExtension.compareToIgnoreCase(FILE_EXTENSION_BMP) == 0){
byImage = convertToBmpByte(bmpImage); // convert bitmap to binary for latter use
} else {
cancel(true);
return null;
}
if(byImage == null) {
cancel(true);
return null;
}
File imageFolder = ctx.getExternalCacheDir();
if(imageFolder.exists() == false){
if(imageFolder.mkdirs() == false){
cancel(true);
return null;
}
}
File imageFile = null;
try {
imageFile = File.createTempFile(strFileName, strFileExtension, imageFolder);
} catch (IOException e){
e.printStackTrace();
}
if(imageFile == null){
cancel(true);
return null;
}
if (imageFile.exists() == true) {
if(imageFile.delete() == false){
cancel(true);
return null;
}
}
FileOutputStream fos = null;
try {
fos = new FileOutputStream(imageFile.getPath());
fos.write(byImage);
fos.flush();
fos.close();
} catch (java.io.IOException e) {
e.printStackTrace();
} finally {
fos = null;
}
return imageFile;
}
@Override
protected void onPostExecute(File file) {
super.onPostExecute(file);
String strAuthority = ctx.getPackageName() + ".provider";
Uri uriImage = FileProvider.getUriForFile(ctx, strAuthority, file);
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(uriImage, "image/*");
intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
ctx.startActivity(intent);
}
}.execute(strBase64Image);}
不要忘记在AndroidManifest.xml中首先设置一个适当的文件提供程序
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="${applicationId}.provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths"/>
</provider>
文件路径是XML在…/res/ XML /file_path.xml
<?xml version="1.0" encoding="utf-8"?>
<external-files-path name="external_files" path="Accessory"/>
<external-path name="ex_Download" path="Download/" />
<external-path name="ex_Pictures" path="Pictures/" />
<external-files-path name="my_Download" path="Download/" />
<external-files-path name="my_Pictures" path="Pictures/" />
<external-cache-path name="my_cache" path="." />
<files-path name="private_Download" path="Download/" />
<files-path name="private_Pictures" path="Pictures/" />
<cache-path name="private_cache" path="." />
长话短说，首先准备好文件提供程序，将已知且可访问的图片源的Uri传递给Intent，否则，将图片保存在所需的位置，然后将位置(作为Uri)传递给Intent。
其他回答
以上答案正确。我遇到了一个不同的问题，在HTC M8中，我的应用程序在从图库中选择图像时崩溃。我得到的图像路径是空值。我用以下解决方案进行了修正和优化。onActivityResult方法
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if ((requestCode == RESULT_LOAD_IMAGE) && (resultCode == RESULT_OK)) {
if (data != null) {
Uri selectedImageUri = null;
selectedImageUri = data.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA };
Cursor imageCursor = mainActivity.getContentResolver().query(
selectedImageUri, filePathColumn, null, null, null);
if (imageCursor == null) {
return;
}
imageCursor.moveToFirst();
int columnIndex = imageCursor.getColumnIndex(filePathColumn[0]);
picturePath = imageCursor.getString(columnIndex);
if (picturePath == null) {
picturePath = selectedImageUri.getPath();
String wholeID = DocumentsContract
.getDocumentId(selectedImage);
// Split at colon, use second item in the array
String id = wholeID.split(":")[1];
String[] column = { MediaStore.Images.Media.DATA };
// where id is equal to
String sel = MediaStore.Images.Media._ID + "=?";
Cursor cursor = mainActivity.getContentResolver().query(
MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
column, sel, new String[] { id }, null);
columnIndex = cursor.getColumnIndex(column[0]);
if (cursor.moveToFirst()) {
picturePath = cursor.getString(columnIndex);
}
cursor.close();
}
picturePathAbs = new File(picturePath).getAbsolutePath();
imageCursor.close();
}
}
package com.ImageConvertingDemo;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.widget.EditText;
import android.widget.ImageView;
public class MyActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
EditText tv = (EditText)findViewById(R.id.EditText01);
ImageView iv = (ImageView)findViewById(R.id.ImageView01);
FileInputStream in;
BufferedInputStream buf;
try
{
in = new FileInputStream("/sdcard/smooth.png");
buf = new BufferedInputStream(in,1070);
System.out.println("1.................."+buf);
byte[] bMapArray= new byte[buf.available()];
tv.setText(bMapArray.toString());
buf.read(bMapArray);
Bitmap bMap = BitmapFactory.decodeByteArray(bMapArray, 0, bMapArray.length);
/*for (int i = 0; i < bMapArray.length; i++)
{
System.out.print("bytearray"+bMapArray[i]);
}*/
iv.setImageBitmap(bMap);
//tv.setText(bMapArray.toString());
//tv.setText(buf.toString());
if (in != null)
{
in.close();
}
if (buf != null)
{
buf.close();
}
}
catch (Exception e)
{
Log.e("Error reading file", e.toString());
}
}
}
这是我的例子，可能不完全是你的情况。
假设你从你的API提供者获得base64格式，给它一个文件名和文件扩展名，将它保存到文件系统中的某个位置。
public static void shownInBuiltInGallery(final Context ctx, String strBase64Image, final String strFileName, final String strFileExtension){
new AsyncTask<String, String, File>() {
@Override
protected File doInBackground(String... strBase64Image) {
Bitmap bmpImage = convertBase64StringToBitmap(strBase64Image[0], Base64.NO_WRAP);
if(bmpImage == null) {
cancel(true);
return null;
}
byte[] byImage = null;
if(strFileExtension.compareToIgnoreCase(FILE_EXTENSION_JPG) == 0) {
byImage = convertToJpgByte(bmpImage); // convert bitmap to binary for latter use
} else if(strFileExtension.compareToIgnoreCase(FILE_EXTENSION_PNG) == 0){
byImage = convertToPngByte(bmpImage); // convert bitmap to binary for latter use
} else if(strFileExtension.compareToIgnoreCase(FILE_EXTENSION_BMP) == 0){
byImage = convertToBmpByte(bmpImage); // convert bitmap to binary for latter use
} else {
cancel(true);
return null;
}
if(byImage == null) {
cancel(true);
return null;
}
File imageFolder = ctx.getExternalCacheDir();
if(imageFolder.exists() == false){
if(imageFolder.mkdirs() == false){
cancel(true);
return null;
}
}
File imageFile = null;
try {
imageFile = File.createTempFile(strFileName, strFileExtension, imageFolder);
} catch (IOException e){
e.printStackTrace();
}
if(imageFile == null){
cancel(true);
return null;
}
if (imageFile.exists() == true) {
if(imageFile.delete() == false){
cancel(true);
return null;
}
}
FileOutputStream fos = null;
try {
fos = new FileOutputStream(imageFile.getPath());
fos.write(byImage);
fos.flush();
fos.close();
} catch (java.io.IOException e) {
e.printStackTrace();
} finally {
fos = null;
}
return imageFile;
}
@Override
protected void onPostExecute(File file) {
super.onPostExecute(file);
String strAuthority = ctx.getPackageName() + ".provider";
Uri uriImage = FileProvider.getUriForFile(ctx, strAuthority, file);
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setDataAndType(uriImage, "image/*");
intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
ctx.startActivity(intent);
}
}.execute(strBase64Image);}
不要忘记在AndroidManifest.xml中首先设置一个适当的文件提供程序
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="${applicationId}.provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths"/>
</provider>
文件路径是XML在…/res/ XML /file_path.xml
<?xml version="1.0" encoding="utf-8"?>
<external-files-path name="external_files" path="Accessory"/>
<external-path name="ex_Download" path="Download/" />
<external-path name="ex_Pictures" path="Pictures/" />
<external-files-path name="my_Download" path="Download/" />
<external-files-path name="my_Pictures" path="Pictures/" />
<external-cache-path name="my_cache" path="." />
<files-path name="private_Download" path="Download/" />
<files-path name="private_Pictures" path="Pictures/" />
<cache-path name="private_cache" path="." />
长话短说，首先准备好文件提供程序，将已知且可访问的图片源的Uri传递给Intent，否则，将图片保存在所需的位置，然后将位置(作为Uri)传递给Intent。
除了前面的答案，如果你在获得正确的路径(如AndroZip)有问题，你可以使用这个:
public String getPath(Uri uri ,ContentResolver contentResolver) {
String[] projection = { MediaStore.MediaColumns.DATA};
Cursor cursor;
try{
cursor = contentResolver.query(uri, projection, null, null, null);
} catch (SecurityException e){
String path = uri.getPath();
String result = tryToGetStoragePath(path);
return result;
}
if(cursor != null) {
//HERE YOU WILL GET A NULLPOINTER IF CURSOR IS NULL
//THIS CAN BE, IF YOU USED OI FILE MANAGER FOR PICKING THE MEDIA
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
String filePath = cursor.getString(columnIndex);
cursor.close();
return filePath;
}
else
return uri.getPath(); // FOR OI/ASTRO/Dropbox etc
}
private String tryToGetStoragePath(String path) {
int actualPathStart = path.indexOf("//storage");
String result = path;
if(actualPathStart!= -1 && actualPathStart< path.length())
result = path.substring(actualPathStart+1 , path.length());
return result;
}
在上面代码的基础上，我反映了如下代码，可能它更适合:
public String getPath(Uri uri) {
String selectedImagePath;
//1:MEDIA GALLERY --- query from MediaStore.Images.Media.DATA
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = managedQuery(uri, projection, null, null, null);
if(cursor != null){
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
selectedImagePath = cursor.getString(column_index);
}else{
selectedImagePath = null;
}
if(selectedImagePath == null){
//2:OI FILE Manager --- call method: uri.getPath()
selectedImagePath = uri.getPath();
}
return selectedImagePath;
}
推荐文章
- 警告:API ' variable . getjavacompile()'已过时，已被' variable . getjavacompileprovider()'取代
- 安装APK时出现错误
- 碎片中的onCreateOptionsMenu
- TextView粗体通过XML文件?
- 如何使线性布局的孩子之间的空间?
- DSL元素android.dataBinding。enabled'已过时，已被'android.buildFeatures.dataBinding'取代
- ConstraintLayout:以编程方式更改约束
- PANIC: AVD系统路径损坏。检查ANDROID_SDK_ROOT值
- 如何生成字符串类型的buildConfigField
- Recyclerview不调用onCreateViewHolder
- Android API 21工具栏填充
- Android L中不支持操作栏导航模式
- 如何在TextView中添加一个子弹符号?
- PreferenceManager getDefaultSharedPreferences在Android Q中已弃用
- 在Android Studio中创建aar文件
