当我尝试将图像从相机设置为图像视图时，ImageView返回空白。我已经给了Manifest和一切的权限。它仍然无法正常工作。自上周以来，我一直坚持这一点。请帮忙。这是代码：
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logcat的：
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class MainActivity extends AppCompatActivity
{
static final int REQUEST_IMAGE_CAPTURE = 1;
static final int REQUEST_TAKE_PHOTO = 1;
String mCurrentPhotoPath;
ImageView mImageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button = (Button) findViewById(R.id.button);
mImageView = (ImageView) findViewById(R.id.imageView);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
{
dispatchTakePictureIntent();
}
});
}
private File createImageFile() throws IOException {
// Create an image file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_";
File storageDir = Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES);
File image = File.createTempFile(
imageFileName, /* prefix */
".jpg", /* suffix */
storageDir /* directory */
);
// Save a file: path for use with ACTION_VIEW intents
mCurrentPhotoPath = "file:" + image.getAbsolutePath();
Log.d("","file place:"+mCurrentPhotoPath);
return image;
}
private void dispatchTakePictureIntent() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
// Create the File where the photo should go
File photoFile = null;
try {
photoFile = createImageFile();
} catch (IOException ex) {
// Error occurred while creating the File
}
// Continue only if the File was successfully created
if (photoFile != null) {
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(photoFile));
startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
}
}
}
public static Bitmap decodeSampledBitmapFromFile(String path,
int reqWidth, int reqHeight) { // BEST QUALITY MATCH
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path, options);
// Calculate inSampleSize
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
options.inPreferredConfig = Bitmap.Config.RGB_565;
int inSampleSize = 1;
if (height > reqHeight) {
inSampleSize = Math.round((float) height / (float) reqHeight);
}
int expectedWidth = width / inSampleSize;
if (expectedWidth > reqWidth) {
//if(Math.round((float)width / (float)reqWidth) > inSampleSize) // If bigger SampSize..
inSampleSize = Math.round((float) width / (float) reqWidth);
}
options.inSampleSize = inSampleSize;
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(path, options);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
//setPic();
File file = new File(Environment.getExternalStorageDirectory()+File.separator + "image.jpg");
mImageView = (ImageView) findViewById(R.id.imageView);
mImageView.setImageBitmap(decodeSampledBitmapFromFile(file.getAbsolutePath(), 500, 250));
}
}
答案 0 :(得分：0)
尝试将代码更改为
<强> onActivityResult
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
//setPic();
if(resultCode == RESULT_OK && requestCode == REQUEST_TAKE_PHOTO){
Log.d("onActivityResult","file place:"+mCurrentPhotoPath);
mImageView.setImageBitmap(decodeSampledBitmapFromFile(mCurrentPhotoPath, 500, 250));
}
}
<强> createImageFile
private File createImageFile() throws IOException {
// Create an image file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_";
File storageDir = Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES);
File image = File.createTempFile(
imageFileName, /* prefix */
".jpg", /* suffix */
storageDir /* directory */
);
// Save a file: path for use with ACTION_VIEW intents
mCurrentPhotoPath = image.getAbsolutePath();
Log.d("","file place:"+mCurrentPhotoPath);
return image;
}
答案 1 :(得分：0)
这是问题所在。当您发送获取图片的意图时，您将提供一个Uri来将图像写入。
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photoFile));
然而，在onActivityResult方法中，您正在创建一个全新的文件（将为空）并将ImageView对象设置为从该文件中提取的位图。
以下是解决此问题的方法。
1）使用您传递给意图的文件
// Make this a class variable
File photoFile;
private void dispatchTakePictureIntent() {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
// Create the File where the photo should go
photoFile = null;
try {
photoFile = createImageFile();
} catch (IOException ex) {
// Error occurred while creating the File
}
// Continue only if the File was successfully created
if (photoFile != null) {
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT,
Uri.fromFile(photoFile));
startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
}
}
}
然后在onActivityResult方法中：
mImageView = (ImageView) findViewById(R.id.imageView);
mImageView.setImageBitmap(decodeSampledBitmapFromFile(photoFile.getAbsolutePath(), 500, 250));
您可以保存文件路径并重新初始化onActivityResult
2）或者，如果您只想将结果设置为imageView，我建议：
删除此行
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photoFile));
在onActivityResult：
if (result == Activity.RESULT_OK && data != null && data.getData() != null) {
mImageView = (ImageView) findViewById(R.id.imageView);
// data.getData() will return the bitmap
mImageView.setImageBitmap(data.getData());
}
请注意，在完成其余操作之前，您应该先检查(requestCode == TAKE_PHOTO_REQUEST)，因为您要确保这是对您拍摄照片的请求的回复
答案 2 :(得分：0)
String imageFileName,imagePath;
private void clickPhotoFromCamera() {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
imageFileName = "JPEG_" + timeStamp + ".jpg";
File imageStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM), imageFileName);
uri = Uri.fromFile(imageStorageDir);
intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
startActivityForResult(intent, 1);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if (requestCode == 1) {
imagePath = uri.getPath();
Bitmap myBitmap = BitmapFactory.decodeFile(imagePath.getAbsolutePath());
imageView.setImageBitmap(myBitmap);
}
}
}