Android 从照相机或多媒体资料在imageview中加载图像
在我的活动中，我想在图像中查看来自照相机或画廊的照片！从参考资料中，我们得到了这方面的代码Android 从照相机或多媒体资料在imageview中加载图像,android,Android,在我的活动中，我想在图像中查看来自照相机或画廊的照片！从参考资料中，我们得到了这方面的代码 private void selectImage() { final CharSequence[] items = { "Take Photo", "Choose from Library", "Cancel" }; AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
private void selectImage() {
final CharSequence[] items = { "Take Photo", "Choose from Library",
"Cancel" };
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setTitle("Add Photo!");
builder.setItems(items, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int item) {
if (items[item].equals("Take Photo")) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, REQUEST_CAMERA);
} else if (items[item].equals("Choose from Library")) {
Intent intent = new Intent(
Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
intent.setType("image/*");
startActivityForResult(
Intent.createChooser(intent, "Select File"),
SELECT_FILE);
} else if (items[item].equals("Cancel")) {
dialog.dismiss();
}
}
});
builder.show();
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == Activity.RESULT_OK) {
if (requestCode == SELECT_FILE)
onSelectFromGalleryResult(data);
else if (requestCode == REQUEST_CAMERA)
onCaptureImageResult(data);
}
}
private void onCaptureImageResult(Intent data) {
Bitmap thumbnail = (Bitmap) data.getExtras().get("data");
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
thumbnail.compress(Bitmap.CompressFormat.JPEG, 90, bytes);
File destination = new File(Environment.getExternalStorageDirectory(),
System.currentTimeMillis() + ".jpg");
FileOutputStream fo;
try {
destination.createNewFile();
fo = new FileOutputStream(destination);
fo.write(bytes.toByteArray());
fo.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
ivImage.setImageBitmap(thumbnail);
}
@SuppressWarnings("deprecation")
private void onSelectFromGalleryResult(Intent data) {
Uri selectedImageUri = data.getData();
String[] projection = { MediaColumns.DATA };
Cursor cursor = managedQuery(selectedImageUri, projection, null, null,
null);
int column_index = cursor.getColumnIndexOrThrow(MediaColumns.DATA);
cursor.moveToFirst();
String selectedImagePath = cursor.getString(column_index);
Bitmap bm;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(selectedImagePath, options);
final int REQUIRED_SIZE = 200;
int scale = 1;
while (options.outWidth / scale / 2 >= REQUIRED_SIZE
&& options.outHeight / scale / 2 >= REQUIRED_SIZE)
scale *= 2;
options.inSampleSize = scale;
options.inJustDecodeBounds = false;
bm = BitmapFactory.decodeFile(selectedImagePath, options);
ivImage.setImageBitmap(bm);
}
它不会在imageview中显示捕获图像，并且该活动已移动到主活动。有人告诉我此方法发生了什么，以及如何修复此方法吗
private void selectImage() {
final CharSequence[] options = { "Take Photo", "Gallery" };
AlertDialog.Builder builder = new AlertDialog.Builder(
EditProfileActivity.this);
builder.setItems(options, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int item) {
if (options[item].equals("Take Photo")) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
File f = new File(android.os.Environment
.getExternalStorageDirectory(), "temp.jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(f));
startActivityForResult(intent, 1);
} else if (options[item].equals("Gallery")) {
Intent intent = new Intent(
Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, 2);
}
}
});
builder.show();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if (requestCode == 1) {
// onCaptureImageResult(data);
try {
File f = new File(Environment.getExternalStorageDirectory()
.toString());
for (File temp : f.listFiles()) {
if (temp.getName().equals("temp.jpg")) {
f = temp;
break;
}
}
Bitmap bitmap;
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmap = BitmapFactory.decodeFile(f.getAbsolutePath(),
bitmapOptions);
imgPic.setImageBitmap(bitmap);
String path = android.os.Environment
.getExternalStorageDirectory()
+ File.separator
+ "Phoenix" + File.separator + "default";
f.delete();
OutputStream outFile = null;
File file = new File(path, String.valueOf(System
.currentTimeMillis()) + ".jpg");
try {
outFile = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 85, outFile);
outFile.flush();
outFile.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
} catch (Exception e) {
e.printStackTrace();
}
} else if (requestCode == 2) {
onSelectFromGalleryResult(data);
}
}
}
private void onSelectFromGalleryResult(Intent data) {
Uri selectedImageUri = data.getData();
String[] projection = { MediaColumns.DATA };
@SuppressWarnings("deprecation")
Cursor cursor = managedQuery(selectedImageUri, projection, null, null,
null);
int column_index = cursor.getColumnIndexOrThrow(MediaColumns.DATA);
cursor.moveToFirst();
String selectedImagePath = cursor.getString(column_index);
Bitmap bm;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(selectedImagePath, options);
final int REQUIRED_SIZE = 200;
int scale = 1;
while (options.outWidth / scale / 2 >= REQUIRED_SIZE
&& options.outHeight / scale / 2 >= REQUIRED_SIZE)
scale *= 2;
options.inSampleSize = scale;
options.inJustDecodeBounds = false;
bm = BitmapFactory.decodeFile(selectedImagePath, options);
imgPic.setImageBitmap(bm);
}
这是我为您编写的代码，它正在工作并经过充分测试，首先您需要在清单中添加权限。您的minifest文件应该如下所示
<?xml version="1.0" encoding="utf-8"?>
<?xml version="1.0" encoding="utf-8"?>
以下代码可以解决您的问题 MainActivity.java 主要活动
System.err:java.lang.NullPointerException:尝试调用虚拟方法'java.lang.String java.io.File.getAbsolutePath（）'在空对象引用上<?xml version="1.0" encoding="utf-8"?>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!"
android:id="@+id/textView" />
<ImageView
android:layout_width="200dp"
android:layout_height="200dp"
android:id="@+id/imageView"
android:layout_below="@+id/textView"
android:layout_toRightOf="@+id/textView"
android:layout_toEndOf="@+id/textView"
android:layout_marginTop="161dp" />
</RelativeLayout>
public class MainActivity extends AppCompatActivity {
private static final int REQUEST_CAMERA = 101;
private static final int SELECT_FILE = 102;
/**
* ATTENTION: This was auto-generated to implement the App Indexing API.
* See https://g.co/AppIndexing/AndroidStudio for more information.
*/
private GoogleApiClient client;
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
selectImage();
}
});
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
private void selectImage() {
final CharSequence[] items = {"Take Photo", "Choose from Library",
"Cancel"};
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setTitle("Add Photo!");
builder.setItems(items, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int item) {
if (items[item].equals("Take Photo")) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
File f = new File(Environment
.getExternalStorageDirectory(), "temp.jpg");
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(f));
startActivityForResult(intent, REQUEST_CAMERA);
} else if (items[item].equals("Choose from Library")) {
Intent intent = new Intent(
Intent.ACTION_PICK,
MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
intent.setType("image/*");
startActivityForResult(
Intent.createChooser(intent, "Select File"),
SELECT_FILE);
} else if (items[item].equals("Cancel")) {
dialog.dismiss();
}
}
});
builder.show();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
if (requestCode == REQUEST_CAMERA) {
File f = new File(Environment.getExternalStorageDirectory()
.toString());
for (File temp : f.listFiles()) {
if (temp.getName().equals("temp.jpg")) {
f = temp;
break;
}
}
try {
Bitmap bm;
BitmapFactory.Options btmapOptions = new BitmapFactory.Options();
bm = BitmapFactory.decodeFile(f.getAbsolutePath(),
btmapOptions);
// bm = Bitmap.createScaledBitmap(bm, 70, 70, true);
ivImage.setImageBitmap(bm);
String path = Environment
.getExternalStorageDirectory()
+ File.separator
+ "Phoenix" + File.separator + "default";
f.delete();
OutputStream fOut = null;
File file = new File(path, String.valueOf(System
.currentTimeMillis()) + ".jpg");
try {
fOut = new FileOutputStream(file);
bm.compress(Bitmap.CompressFormat.JPEG, 85, fOut);
fOut.flush();
fOut.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
} catch (Exception e) {
e.printStackTrace();
}
} else if (requestCode == SELECT_FILE) {
Uri selectedImageUri = data.getData();
String tempPath = getPath(selectedImageUri, MainActivity.this);
Bitmap bm;
BitmapFactory.Options btmapOptions = new BitmapFactory.Options();
bm = BitmapFactory.decodeFile(tempPath, btmapOptions);
ivImage.setImageBitmap(bm);
}
}
}
public String getPath(Uri uri, Activity activity) {
String[] projection = {MediaStore.MediaColumns.DATA};
Cursor cursor = activity
.managedQuery(uri, projection, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
}
@Override
public void onStart() {
super.onStart();
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
client.connect();
Action viewAction = Action.newAction(
Action.TYPE_VIEW, // TODO: choose an action type.
"Main Page", // TODO: Define a title for the content shown.
// TODO: If you have web page content that matches this app activity's content,
// make sure this auto-generated web page URL is correct.
// Otherwise, set the URL to null.
Uri.parse("http://host/path"),
// TODO: Make sure this auto-generated app deep link URI is correct.
Uri.parse("android-app://com.group3amd.myapplication/http/host/path")
);
AppIndex.AppIndexApi.start(client, viewAction);
}
@Override
public void onStop() {
super.onStop();
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
Action viewAction = Action.newAction(
Action.TYPE_VIEW, // TODO: choose an action type.
"Main Page", // TODO: Define a title for the content shown.
// TODO: If you have web page content that matches this app activity's content,
// make sure this auto-generated web page URL is correct.
// Otherwise, set the URL to null.
Uri.parse("http://host/path"),
// TODO: Make sure this auto-generated app deep link URI is correct.
Uri.parse("android-app://com.group3amd.myapplication/http/host/path")
);
AppIndex.AppIndexApi.end(client, viewAction);
client.disconnect();
}
}
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.provider.MediaStore.MediaColumns;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import com.example.takeimage.R;
public class MainActivity extends Activity {
int REQUEST_CAMERA = 0, SELECT_FILE = 1;
Button btnSelect;
ImageView ivImage;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnSelect = (Button) findViewById(R.id.btnSelectPhoto);
btnSelect.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
selectImage();
}
});
ivImage = (ImageView) findViewById(R.id.ivImage);
}
private void selectImage() {
final CharSequence[] items = { "Take Photo", "Choose from Library",
"Cancel" };
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setTitle("Add Photo!");
builder.setItems(items, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int item) {
if (items[item].equals("Take Photo")) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, REQUEST_CAMERA);
} else if (items[item].equals("Choose from Library")) {
Intent intent = new Intent(
Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
intent.setType("image/*");
startActivityForResult(
Intent.createChooser(intent, "Select File"),
SELECT_FILE);
} else if (items[item].equals("Cancel")) {
dialog.dismiss();
}
}
});
builder.show();
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == Activity.RESULT_OK) {
if (requestCode == SELECT_FILE)
onSelectFromGalleryResult(data);
else if (requestCode == REQUEST_CAMERA)
onCaptureImageResult(data);
}
}
private void onCaptureImageResult(Intent data) {
Bitmap thumbnail = (Bitmap) data.getExtras().get("data");
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
thumbnail.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
File destination = new File(Environment.getExternalStorageDirectory(),
System.currentTimeMillis() + ".jpg");
FileOutputStream fo;
try {
destination.createNewFile();
fo = new FileOutputStream(destination);
fo.write(bytes.toByteArray());
fo.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
ivImage.setImageBitmap(thumbnail);
}
@SuppressWarnings("deprecation")
private void onSelectFromGalleryResult(Intent data) {
Uri selectedImageUri = data.getData();
String[] projection = { MediaColumns.DATA };
Cursor cursor = managedQuery(selectedImageUri, projection, null, null,
null);
int column_index = cursor.getColumnIndexOrThrow(MediaColumns.DATA);
cursor.moveToFirst();
String selectedImagePath = cursor.getString(column_index);
Bitmap bm;
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(selectedImagePath, options);
final int REQUIRED_SIZE = 200;
int scale = 1;
while (options.outWidth / scale / 2 >= REQUIRED_SIZE
&& options.outHeight / scale / 2 >= REQUIRED_SIZE)
scale *= 2;
options.inSampleSize = scale;
options.inJustDecodeBounds = false;
bm = BitmapFactory.decodeFile(selectedImagePath, options);
ivImage.setImageBitmap(bm);
}
}
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="10dp" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:padding="5dp" >
<Button
android:id="@+id/btnSelectPhoto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Select Photo" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="vertical"
android:padding="10dp" >
<ImageView
android:id="@+id/ivImage"
android:layout_width="200dp"
android:layout_height="200dp"
android:scaleType="fitXY"
android:adjustViewBounds="true"
android:src="@drawable/ic_launcher" />
</LinearLayout>
</LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.takeimage"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.tag.photocaptureandgallery.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>