我想写一个模块，在点击一个按钮，相机打开，我可以点击和捕捉图像。如果我不喜欢图像，我可以删除它，然后点击另一个图像，然后选择图像，它应该返回并在活动中显示该图像。
当前回答
正如其他人所讨论的，使用data. getextras ().get("data")只会得到低质量的缩略图。
解决方案是通过ACTION_IMAGE_CAPTURE意图传递一个位置，告诉相机在哪里存储全质量图像。
代码是Kotlin，不需要任何权限。
val f = File("${getExternalFilesDir(null)}/imgShot")
val photoURI = FileProvider.getUriForFile(this, "${packageName}.fileprovider", f)
val intent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
.apply { putExtra(MediaStore.EXTRA_OUTPUT, photoURI) }
startActivityForResult(intent, 1234)
然后对拍摄后的结果进行处理:
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
if (requestCode == 1234 && resultCode == Activity.RESULT_OK) {
val bitmap = BitmapFactory.decodeFile(
File("${getExternalFilesDir(null)}/imgShot").toString()
)
// use imageView.setImageBitmap(bitmap) or whatever
}
}
您还需要像这里描述的那样添加一个外部FileProvider。AndroidManifest.xml:
<manifest>
<application>
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/provide_paths" />
</provider>
</application>
</manifest>
添加一个新文件app/src/main/res/xml/provide_paths.xml:
<?xml version="1.0" encoding="utf-8"?>
<paths>
<external-path name="external_files" path="." />
</paths>
最后，你应该用你自己的逻辑替换1234来跟踪请求代码(通常是一个包含RequestCode.CAPTURE_IMAGE等成员的枚举)
其他回答
使用下面的代码捕捉图片使用您的移动相机。 如果你使用的android版本高于棒棒糖，你也应该添加权限请求。
private void cameraIntent()
{
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, REQUEST_CAMERA);
}
@override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == CAMERA_REQUEST && resultCode == Activity.RESULT_OK) {
Bitmap photo = (Bitmap) data.getExtras().get("data");
imageView.setImageBitmap(photo);
}
}
坏的质量
根据我的经验，如果我们使用
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, RESULT_ADD_PHOTO);
和处理onActivityResult()
Bitmap thumbnail= (Bitmap) data.getExtras().get("data");
它只会给你一个缩略图，当然有一个坏的质量。
不错的质量
您可以显示相机和保存您的图像文件在公共目录，例如在文档目录
在onClick()中使用这个
String imagePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS) +
File.separator + "your_image_name.jpeg";
Intent i =new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
imageFile = new File(imagePath );
i.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(imageFile));
startActivityForResult(i, RESULT_ADD_PHOTO);
在onActivityResult()中
Bitmap imageBitmap1 = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
Matrix matrix = new Matrix();
matrix.postRotate(90);
Bitmap imageBitmap = Bitmap.createBitmap(imageBitmap1, 0, 0, imageBitmap1.getWidth(), imageBitmap1.getHeight(), matrix, true);
binding.imageView.setImageBitmap(imageBitmap);
我使用postRotate()，因为在我的代码中，图像结果向左旋转，所以我需要将其旋转90
拍摄照片+从图库中选择:
a = (ImageButton)findViewById(R.id.imageButton1);
a.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
selectImage();
}
});
}
private File savebitmap(Bitmap bmp) {
String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
OutputStream outStream = null;
// String temp = null;
File file = new File(extStorageDirectory, "temp.png");
if (file.exists()) {
file.delete();
file = new File(extStorageDirectory, "temp.png");
}
try {
outStream = new FileOutputStream(file);
bmp.compress(Bitmap.CompressFormat.PNG, 100, outStream);
outStream.flush();
outStream.close();
} catch (Exception e) {
e.printStackTrace();
return null;
}
return file;
}
@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;
}
private void selectImage() {
final CharSequence[] options = { "Take Photo", "Choose from Gallery","Cancel" };
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setTitle("Add Photo!");
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));
//pic = f;
startActivityForResult(intent, 1);
}
else if (options[item].equals("Choose from Gallery"))
{
Intent intent = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, 2);
}
else if (options[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 == 1) {
//h=0;
File f = new File(Environment.getExternalStorageDirectory().toString());
for (File temp : f.listFiles()) {
if (temp.getName().equals("temp.jpg")) {
f = temp;
File photo = new File(Environment.getExternalStorageDirectory(), "temp.jpg");
//pic = photo;
break;
}
}
try {
Bitmap bitmap;
BitmapFactory.Options bitmapOptions = new BitmapFactory.Options();
bitmap = BitmapFactory.decodeFile(f.getAbsolutePath(),
bitmapOptions);
a.setImageBitmap(bitmap);
String path = android.os.Environment
.getExternalStorageDirectory()
+ File.separator
+ "Phoenix" + File.separator + "default";
//p = path;
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);
//pic=file;
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) {
Uri selectedImage = data.getData();
// h=1;
//imgui = selectedImage;
String[] filePath = { MediaStore.Images.Media.DATA };
Cursor c = getContentResolver().query(selectedImage,filePath, null, null, null);
c.moveToFirst();
int columnIndex = c.getColumnIndex(filePath[0]);
String picturePath = c.getString(columnIndex);
c.close();
Bitmap thumbnail = (BitmapFactory.decodeFile(picturePath));
Log.w("path of image from gallery......******************.........", picturePath+"");
a.setImageBitmap(thumbnail);
}
}
正如其他人所讨论的，使用data. getextras ().get("data")只会得到低质量的缩略图。
解决方案是通过ACTION_IMAGE_CAPTURE意图传递一个位置，告诉相机在哪里存储全质量图像。
代码是Kotlin，不需要任何权限。
val f = File("${getExternalFilesDir(null)}/imgShot")
val photoURI = FileProvider.getUriForFile(this, "${packageName}.fileprovider", f)
val intent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
.apply { putExtra(MediaStore.EXTRA_OUTPUT, photoURI) }
startActivityForResult(intent, 1234)
然后对拍摄后的结果进行处理:
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
if (requestCode == 1234 && resultCode == Activity.RESULT_OK) {
val bitmap = BitmapFactory.decodeFile(
File("${getExternalFilesDir(null)}/imgShot").toString()
)
// use imageView.setImageBitmap(bitmap) or whatever
}
}
您还需要像这里描述的那样添加一个外部FileProvider。AndroidManifest.xml:
<manifest>
<application>
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/provide_paths" />
</provider>
</application>
</manifest>
添加一个新文件app/src/main/res/xml/provide_paths.xml:
<?xml version="1.0" encoding="utf-8"?>
<paths>
<external-path name="external_files" path="." />
</paths>
最后，你应该用你自己的逻辑替换1234来跟踪请求代码(通常是一个包含RequestCode.CAPTURE_IMAGE等成员的枚举)
下面是一个示例活动，它将启动相机应用程序，然后检索图像并显示它。
package edu.gvsu.cis.masl.camerademo;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
public class MyCameraActivity extends Activity
{
private static final int CAMERA_REQUEST = 1888;
private ImageView imageView;
private static final int MY_CAMERA_PERMISSION_CODE = 100;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
this.imageView = (ImageView)this.findViewById(R.id.imageView1);
Button photoButton = (Button) this.findViewById(R.id.button1);
photoButton.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)
{
requestPermissions(new String[]{Manifest.permission.CAMERA}, MY_CAMERA_PERMISSION_CODE);
}
else
{
Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, CAMERA_REQUEST);
}
}
});
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults)
{
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == MY_CAMERA_PERMISSION_CODE)
{
if (grantResults[0] == PackageManager.PERMISSION_GRANTED)
{
Toast.makeText(this, "camera permission granted", Toast.LENGTH_LONG).show();
Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, CAMERA_REQUEST);
}
else
{
Toast.makeText(this, "camera permission denied", Toast.LENGTH_LONG).show();
}
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
if (requestCode == CAMERA_REQUEST && resultCode == Activity.RESULT_OK)
{
Bitmap photo = (Bitmap) data.getExtras().get("data");
imageView.setImageBitmap(photo);
}
}
}
请注意，相机应用程序本身提供了查看/重拍图像的功能，一旦图像被接受，活动就会显示它。
下面是上面的活动使用的布局。它只是一个包含id为button1的Button和id为imageview1的ImageView的LinearLayout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/photo"></Button>
<ImageView android:id="@+id/imageView1" android:layout_height="wrap_content" android:src="@drawable/icon" android:layout_width="wrap_content"></ImageView>
</LinearLayout>
最后一个细节，一定要加上:
<uses-feature android:name="android.hardware.camera"></uses-feature>
如果摄像头是你应用功能的可选选项。请确保在权限中将require设置为false。像这样
<uses-feature android:name="android.hardware.camera" android:required="false"></uses-feature>
到你的manifest.xml。
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
