这个问题最初是针对Android 1.6提出的。
我正在开发一个应用中的照片选项。
在我的活动中,我有一个按钮和一个ImageView。当我点击按钮时,它会跳转到相册,我就可以选择一张图片。所选的图片将显示在我的ImageView中。
这个问题最初是针对Android 1.6提出的。
我正在开发一个应用中的照片选项。
在我的活动中,我有一个按钮和一个ImageView。当我点击按钮时,它会跳转到相册,我就可以选择一张图片。所选的图片将显示在我的ImageView中。
更新的答案,接近五年后:
原始答案中的代码已经不再可靠,因为来自不同来源的图像有时会返回具有不同内容URI的content://,而不是file://。更好的解决方案是只需使用context.getContentResolver().openInputStream(intent.getData())
,因为它会返回一个InputStream,您可以根据需要处理它。
例如,BitmapFactory.decodeStream()
在这种情况下完美地工作,因为您还可以使用Options和inSampleSize字段来缩小大型图像并避免内存问题。
但是,像Google Drive之类的东西会返回尚未实际下载的图像的URI。 因此,您需要在后台线程上执行getContentResolver()代码。
原始答案:
其他答案解释了如何发送意图,但没有很好地解释如何处理响应。以下是一些示例代码,用于处理响应:
protected void onActivityResult(int requestCode, int resultCode,
Intent imageReturnedIntent) {
super.onActivityResult(requestCode, resultCode, imageReturnedIntent);
switch(requestCode) {
case REQ_CODE_PICK_IMAGE:
if(resultCode == RESULT_OK){
Uri selectedImage = imageReturnedIntent.getData();
String[] filePathColumn = {MediaStore.Images.Media.DATA};
Cursor cursor = getContentResolver().query(
selectedImage, filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String filePath = cursor.getString(columnIndex);
cursor.close();
Bitmap yourSelectedImage = BitmapFactory.decodeFile(filePath);
}
}
}
接下来,你已经将所选图像存储在“yourSelectedImage”中,可以按照自己的需求进行操作。该代码通过获取ContentResolver数据库中图像的位置来工作,但仅有此信息是不够的。每个图像大约有18列信息,从其文件路径到“上次修改日期”再到拍摄照片的GPS坐标等,尽管许多字段实际上并未使用。
为了节省时间,因为您实际上不需要其他字段,所以使用筛选器进行游标搜索。筛选器通过指定您想要的列的名称MediaStore.Images.Media.DATA(即路径),然后将该字符串[]提供给游标查询。游标查询返回路径,但在使用columnIndex代码之前,您不知道它在哪个列中。columnIndex只是根据其名称获取列的编号,与筛选过程中使用的相同名称。一旦获得了这个数字,您就可以使用我提供的最后一行代码将图像解码为位图。
private static final int SELECT_PHOTO = 100;
开始意图
Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
photoPickerIntent.setType("image/*");
startActivityForResult(photoPickerIntent, SELECT_PHOTO);
处理结果
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
super.onActivityResult(requestCode, resultCode, imageReturnedIntent);
switch(requestCode) {
case SELECT_PHOTO:
if(resultCode == RESULT_OK){
Uri selectedImage = imageReturnedIntent.getData();
InputStream imageStream = getContentResolver().openInputStream(selectedImage);
Bitmap yourSelectedImage = BitmapFactory.decodeStream(imageStream);
}
}
}
或者,您还可以对图像进行下采样以避免OutOfMemory错误。
private Bitmap decodeUri(Uri selectedImage) throws FileNotFoundException {
// Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage), null, o);
// The new size we want to scale to
final int REQUIRED_SIZE = 140;
// Find the correct scale value. It should be the power of 2.
int width_tmp = o.outWidth, height_tmp = o.outHeight;
int scale = 1;
while (true) {
if (width_tmp / 2 < REQUIRED_SIZE
|| height_tmp / 2 < REQUIRED_SIZE) {
break;
}
width_tmp /= 2;
height_tmp /= 2;
scale *= 2;
}
// Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
return BitmapFactory.decodeStream(getContentResolver().openInputStream(selectedImage), null, o2);
}
int scale = 1;
for ( ; bfOptions.outWidth / scale > TARGET_SIZE && bfOptions.outWidth > TARGET_SIZE; scale*=2);
- The_Rafi你需要启动图库意图并获取结果。
Intent i = new Intent(Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, ACTIVITY_SELECT_IMAGE);
接着在onActivityForResult
中调用intent.getData()
以获取图片的Uri。 然后您需要从ContentProvider中获取该图片。
这是一段已测试的图像和视频代码。它适用于所有小于19和大于19的API。
图像:
if (Build.VERSION.SDK_INT <= 19) {
Intent i = new Intent();
i.setType("image/*");
i.setAction(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
startActivityForResult(i, 10);
} else if (Build.VERSION.SDK_INT > 19) {
Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, 10);
}
视频:
if (Build.VERSION.SDK_INT <= 19) {
Intent i = new Intent();
i.setType("video/*");
i.setAction(Intent.ACTION_GET_CONTENT);
i.addCategory(Intent.CATEGORY_OPENABLE);
startActivityForResult(i, 20);
} else if (Build.VERSION.SDK_INT > 19) {
Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Video.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, 20);
}
.
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == Activity.RESULT_OK) {
if (requestCode == 10) {
Uri selectedImageUri = data.getData();
String selectedImagePath = getRealPathFromURI(selectedImageUri);
} else if (requestCode == 20) {
Uri selectedVideoUri = data.getData();
String selectedVideoPath = getRealPathFromURI(selectedVideoUri);
}
}
}
public String getRealPathFromURI(Uri uri) {
if (uri == null) {
return null;
}
String[] projection = {MediaStore.Images.Media.DATA};
Cursor cursor = getActivity().getContentResolver().query(uri, projection, null, null, null);
if (cursor != null) {
int column_index = cursor
.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
return uri.getPath();
}
按照以下方式执行,以启动图库并允许用户选择图像:
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("image/*");
startActivityForResult(intent, IMAGE_PICK);
然后在你的 onActivityResult()
中,使用返回的图像URI设置ImageView上的图像。
public class EMView extends Activity {
ImageView img,img1;
int column_index;
Intent intent=null;
// Declare our Views, so we can access them later
String logo,imagePath,Logo;
Cursor cursor;
//YOU CAN EDIT THIS TO WHATEVER YOU WANT
private static final int SELECT_PICTURE = 1;
String selectedImagePath;
//ADDED
String filemanagerstring;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
img= (ImageView)findViewById(R.id.gimg1);
((Button) findViewById(R.id.Button01))
.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
// in onCreate or any event where your want the user to
// select a file
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent,
"Select Picture"), SELECT_PICTURE);
}
});
}
//UPDATED
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == Activity.RESULT_OK) {
if (requestCode == SELECT_PICTURE) {
Uri selectedImageUri = data.getData();
//OI FILE Manager
filemanagerstring = selectedImageUri.getPath();
//MEDIA GALLERY
selectedImagePath = getPath(selectedImageUri);
img.setImageURI(selectedImageUri);
imagePath.getBytes();
TextView txt = (TextView)findViewById(R.id.title);
txt.setText(imagePath.toString());
Bitmap bm = BitmapFactory.decodeFile(imagePath);
// img1.setImageBitmap(bm);
}
}
}
//UPDATED!
public String getPath(Uri uri) {
String[] projection = { MediaColumns.DATA };
Cursor cursor = managedQuery(uri, projection, null, null, null);
column_index = cursor
.getColumnIndexOrThrow(MediaColumns.DATA);
cursor.moveToFirst();
imagePath = cursor.getString(column_index);
return cursor.getString(column_index);
}
}
public class BrowsePictureActivity extends Activity {
private static final int SELECT_PICTURE = 1;
private String selectedImagePath;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
((Button) findViewById(R.id.Button01))
.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent,
"Select Picture"), SELECT_PICTURE);
}
});
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
if (requestCode == SELECT_PICTURE) {
Uri selectedImageUri = data.getData();
selectedImagePath = getPath(selectedImageUri);
}
}
}
public String getPath(Uri uri) {
if( uri == null ) {
return null;
}
// this will only work for images selected from gallery
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();
return cursor.getString(column_index);
}
return uri.getPath();
}
}
onActivityResult()
尝试对接收到的 Uri
进行后处理,例如获取图像的真实路径,然后使用 BitmapFactory.decodeFile(path)
来获取 Bitmap
。ImageView
类有一个名为 setImageURI(uri)
的方法。将您的 uri 传递给它,然后就可以了。Uri imageUri = data.getData();
imageView.setImageURI(imageUri);
像这样调用chooseImage方法:
public void chooseImage(ImageView v)
{
Intent intent = new Intent(Intent.ACTION_PICK);
intent.setType("image/*");
startActivityForResult(intent, SELECT_PHOTO);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, imageReturnedIntent);
if(imageReturnedIntent != null)
{
Uri selectedImage = imageReturnedIntent.getData();
switch(requestCode) {
case SELECT_PHOTO:
if(resultCode == RESULT_OK)
{
Bitmap datifoto = null;
temp.setImageBitmap(null);
Uri picUri = null;
picUri = imageReturnedIntent.getData();//<- get Uri here from data intent
if(picUri !=null){
try {
datifoto = android.provider.MediaStore.Images.Media.getBitmap(this.getContentResolver(), picUri);
temp.setImageBitmap(datifoto);
} catch (FileNotFoundException e) {
throw new RuntimeException(e);
} catch (IOException e) {
throw new RuntimeException(e);
} catch (OutOfMemoryError e) {
Toast.makeText(getBaseContext(), "Image is too large. choose other", Toast.LENGTH_LONG).show();
}
}
}
break;
}
}
else
{
//Toast.makeText(getBaseContext(), "data null", Toast.LENGTH_SHORT).show();
}
}
#initialize in main activity
path = Environment.getExternalStorageDirectory()
+ "/images/make_machine_example.jpg"; #
ImageView image=(ImageView)findViewById(R.id.image);
//--------------------------------------------------||
public void FromCamera(View) {
Log.i("camera", "startCameraActivity()");
File file = new File(path);
Uri outputFileUri = Uri.fromFile(file);
Intent intent = new Intent(
android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
startActivityForResult(intent, 1);
}
public void FromCard() {
Intent i = new Intent(Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(i, 2);
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 2 && resultCode == RESULT_OK
&& null != data) {
Uri selectedImage = data.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(selectedImage,
filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String picturePath = cursor.getString(columnIndex);
cursor.close();
bitmap = BitmapFactory.decodeFile(picturePath);
image.setImageBitmap(bitmap);
if (bitmap != null) {
ImageView rotate = (ImageView) findViewById(R.id.rotate);
}
} else {
Log.i("SonaSys", "resultCode: " + resultCode);
switch (resultCode) {
case 0:
Log.i("SonaSys", "User cancelled");
break;
case -1:
onPhotoTaken();
break;
}
}
}
protected void onPhotoTaken() {
// Log message
Log.i("SonaSys", "onPhotoTaken");
taken = true;
imgCapFlag = true;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 4;
bitmap = BitmapFactory.decodeFile(path, options);
image.setImageBitmap(bitmap);
}