我正在尝试使用以下代码拍摄照片并在屏幕上查看：
public class MainActivity extends ActionBarActivity {
private static final int PICTURE_REQUEST_CODE = 100;
public Button camera, gallery;
private Uri fileUri;
private static File mediaFile;
ImageView image;
public String fileName;
@Override
protected void onCreate(Bundle savedInstanceState) {
System.out.println("Started Main Activity");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
camera = (Button) findViewById(R.id.button1);
gallery = (Button) findViewById(R.id.button2);
createListeners();
}
private static Uri getOutputMediaFile(){
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "Mustache");
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_"+ timeStamp + ".jpg");
return Uri.fromFile(mediaFile);
}
public void launchCamera(){
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
fileUri = getOutputMediaFile(); // create a file to save the image
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
startActivityForResult(intent, PICTURE_REQUEST_CODE);
}
public void launchGallery(){
Intent gallery = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
fileUri = getOutputMediaFile(); // create a file to save the image
gallery.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
startActivityForResult(gallery, PICTURE_REQUEST_CODE);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
System.out.println(String.valueOf(requestCode));
System.out.println(String.valueOf(resultCode));
System.out.println(data);
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
Uri contentUri = Uri.fromFile(mediaFile);
mediaScanIntent.setData(contentUri);
this.sendBroadcast(mediaScanIntent);
}
public static final int MEDIA_TYPE_VIDEO = 2;
private void createListeners() {
System.out.println("Started CreateListeners for Main Activity");
camera.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
launchCamera();
}
});
gallery.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
launchGallery();
}
});
}
}
XML：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
tools:context="com.example.mustache.MainActivity"
tools:ignore="MergeRootFrame" >
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_weight="1"
android:text="@string/main_camera_button" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:layout_weight="1"
android:text="@string/main_gallery_button" />
</LinearLayout>
然而，应用程序拍摄照片并将其保存到我的图库，但随后返回主屏幕而不做任何事情。如何让它显示照片？
答案 0 :(得分：4)
唯一的问题是您没有显示捕获的图像。
您需要在ImageView中添加Layout并在onActivityResult
像这样更改onActivityResult
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
Uri contentUri = Uri.fromFile(mediaFile);
ImageView imageView = (ImageView)findViewById(R.id.imageView1);
imageView.setImageURI(contentUri);
}
另外，在布局中添加ImageView
<ImageView
android:id="@+id/imageView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:layout_weight="1"/>
答案 1 :(得分：1)
除了一件事，一切看起来都很好：你刚刚创建了ImageView对象但没有引用。您应该对代码进行一些更改，如下所示：
将ImageView添加到xml布局文件中：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="fill_parent"
android:orientation="horizontal"
tools:context="com.example.mustache.MainActivity"
tools:ignore="MergeRootFrame" >
<Button .... />
<Button .... />
<ImageView
android:id="@+id/imageview"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_gravity="center" />
</LinearLayout>
然后引用您的Activity类：
public class MainActivity extends ActionBarActivity
{
private static final int PICTURE_REQUEST_CODE = 100;
public Button camera, gallery;
ImageView image;
.........
........
protected void onCreate(Bundle savedInstanceState) {
System.out.println("Started Main Activity");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
image = (ImageView)findViewById(R.id.imageview);
}
然后到 onActivityResult
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
System.out.println(String.valueOf(requestCode));
System.out.println(String.valueOf(resultCode));
System.out.println(data);
if(resulCode == RESULT_OK && requestCode == PICTURE_REQUEST_CODE)
{
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
Uri contentUri = Uri.fromFile(mediaFile);
image.setImageUri(contentUri);//set uri of captured image to imageview
mediaScanIntent.setData(contentUri);
this.sendBroadcast(mediaScanIntent);
}
}
确保为启动相机和从图库中选择图像设置不同的RequestCode。
答案 2 :(得分：1)
您需要Imageview：
public class MainActivity extends ActionBarActivity {
private static final int PICTURE_REQUEST_CODE = 100;
public Button camera, gallery;
private Uri fileUri;
private static File mediaFile;
ImageView image;
public String fileName;
@Override
protected void onCreate(Bundle savedInstanceState) {
System.out.println("Started Main Activity");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
camera = (Button) findViewById(R.id.button1);
gallery = (Button) findViewById(R.id.button2);
createListeners();
}
private static Uri getOutputMediaFile(){
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "Mustache");
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_"+ timeStamp + ".jpg");
return Uri.fromFile(mediaFile);
}
public void launchCamera(){
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
fileUri = getOutputMediaFile(); // create a file to save the image
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
startActivityForResult(intent, PICTURE_REQUEST_CODE);
}
public void launchGallery(){
Intent gallery = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
fileUri = getOutputMediaFile(); // create a file to save the image
gallery.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
startActivityForResult(gallery, PICTURE_REQUEST_CODE);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
System.out.println(String.valueOf(requestCode));
System.out.println(String.valueOf(resultCode));
System.out.println(data);
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
Uri contentUri = Uri.fromFile(mediaFile);
mediaScanIntent.setData(contentUri);
this.sendBroadcast(mediaScanIntent);
}
public static final int MEDIA_TYPE_VIDEO = 2;
private void createListeners() {
System.out.println("Started CreateListeners for Main Activity");
camera.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
launchCamera();
}
});
gallery.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
launchGallery();
}
});
}
}
答案 3 :(得分：0)
这是一种简单的技术。您应该使用AlertDialog.Builder来显示3个选项，如：
1）从相机拍摄照片 2）从画廊中选择 3）取消
然后按照以下步骤进行操作
请参阅以下代码以获取帮助......
ImageView profile_img; //When you select image either from Gallery or take from Camera the code will set your selected image to this ImageView...
Context context;
final CharSequence[] items = { "Take Picture from camera", "Choose from gallery", "Cancel" };
private static final int REQUEST_CAMERA = 0;
private static final int SELECT_IMAGE = 1;
Bitmap bmp;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.your_xml_layout_name);
context = YourActivityClass.this;
profile_img = (ImageView) findViewById(R.id.profile_img);
profile_img.setOnClickListener(this);
}
@Override
public void onClick(View v)
{
int id = v.getId();
switch (id)
{
case R.id.profile_img:
selectImage();
break;
}
}
private void selectImage()
{
AlertDialog.Builder alert = new AlertDialog.Builder(context);
alert.setTitle("Choose Options...");
alert.setItems(items, new DialogInterface.OnClickListener()
{
@Override
public void onClick(DialogInterface dialog, int position)
{
if(items[position].equals("Take Picture from camera"))
{
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, REQUEST_CAMERA);
}
else if(items[position].equals("Choose from gallery"))
{
Intent intent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, SELECT_IMAGE);
}
else if(items[position].equals("Cancel"))
{
dialog.dismiss();
}
}
});
alert.show();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
if(resultCode == RESULT_OK)
{
if(requestCode == REQUEST_CAMERA)
{
Uri uri = (Uri) data.getData();
try
{
bmp = decodeUri(uri);
profile_img.setImageBitmap(bmp);
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
}
else if(requestCode == SELECT_IMAGE)
{
Uri uri = data.getData();
try
{
bmp = decodeUri(uri);
profile_img.setImageBitmap(bmp);
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
}
}
}
public String getPath(Uri uri)
{
String[] projection = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(uri, projection, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
private Bitmap decodeUri(Uri selectedImage) throws FileNotFoundException
{
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeStream(
getContentResolver().openInputStream(selectedImage), null, o);
final int REQUIRED_SIZE = 70;
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;
}
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
return BitmapFactory.decodeStream(
getContentResolver().openInputStream(selectedImage), null, o2);
}
希望这会对你有所帮助......祝你好运
答案 4 :(得分：0)
// try this way,hope this will help you...
**XML** code
**activity_main**
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="10dp"
android:gravity="center">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:gravity="center"
android:layout_weight="1">
<ImageView
android:id="@+id/imageView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:src="@drawable/ic_launcher"/>
</LinearLayout>
<Button
android:id="@+id/btnCamera"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:text="Camera" />
<Button
android:id="@+id/btnGallery"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:text="Gallery" />
</LinearLayout>
**ACTIVITY** code
**MainActivity**
public class MainActivity extends Activity {
final private int PICK_IMAGE = 1;
final private int CAPTURE_IMAGE = 2;
private Button btnCamera;
private Button btnGallery;
private ImageView imageView;
private String imgPath;
@Override
protected void onCreate(Bundle savedInstanceState) {
System.out.println("Started Main Activity");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnCamera = (Button) findViewById(R.id.btnCamera);
btnGallery = (Button) findViewById(R.id.btnGallery);
imageView = (ImageView) findViewById(R.id.imageView);
btnCamera.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
final Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, setImageUri());
startActivityForResult(intent, CAPTURE_IMAGE);
}
});
btnGallery.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, ""), PICK_IMAGE);
}
});
}
public Uri setImageUri() {
// Store image in dcim
File file = new File(Environment.getExternalStorageDirectory() + "/DCIM/", "image" + new Date().getTime() + ".jpg");
Uri imgUri = Uri.fromFile(file);
this.imgPath = file.getAbsolutePath();
return imgUri;
}
public String getImagePath() {
return imgPath;
}
public String getAbsolutePath(Uri uri) {
if(Build.VERSION.SDK_INT >= 19){
String id = uri.getLastPathSegment().split(":")[1];
final String[] imageColumns = {MediaStore.Images.Media.DATA };
final String imageOrderBy = null;
Uri tempUri = getUri();
Cursor imageCursor = managedQuery(tempUri, imageColumns,
MediaStore.Images.Media._ID + "="+id, null, imageOrderBy);
if (imageCursor.moveToFirst()) {
return imageCursor.getString(imageCursor.getColumnIndex(MediaStore.Images.Media.DATA));
}else{
return null;
}
}else{
String[] projection = { MediaStore.MediaColumns.DATA };
@SuppressWarnings("deprecation")
Cursor cursor = managedQuery(uri, projection, null, null, null);
if (cursor != null) {
int column_index = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
} else
return null;
}
}
private Uri getUri() {
String state = Environment.getExternalStorageState();
if(!state.equalsIgnoreCase(Environment.MEDIA_MOUNTED))
return MediaStore.Images.Media.INTERNAL_CONTENT_URI;
return MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == Activity.RESULT_OK) {
if (requestCode == CAPTURE_IMAGE) {
imageView.setImageBitmap(BitmapFactory.decodeFile(getImagePath()));
} else if (requestCode == PICK_IMAGE) {
imageView.setImageBitmap(BitmapFactory.decodeFile(getAbsolutePath(data.getData())));
}
}
}
}
Note : add this permission on you "AndroidManifest.xml"
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />