如何在位置保存图像并在Android App中将其检索为imageView? [英] How to get save an image at location and retrieve it for imageView in Android App?
问题描述
我正在构建一个在Android中使用的简单相机应用,以在imageView
中显示它.我可以获得非常模糊的缩略图.因此,我为此创建了一个文件,然后它给了我文件的位置.当我检查它时,它的大小为0 kb,这是众所周知的.
我的任务是捕获图像并保存在mCurrentPhotoPath
上,我应该能够在startActivityForResult()
I am building a simple camera app in Android to show it in a imageView
.I can get thumbnail which is very blurr .So I have a made file for that and then It gives me the location of the file. When I check it ,Its is of 0 kb which is well understood .
My Task is to capture image and save at mCurrentPhotoPath
and I should be able to display it in my imageView
in startActivityForResult()
但是应用程序崩溃在校准之前一遍又一遍. 我知道这行有问题
But App Crashes Before Caling Before that again and again. I know something is buggy in this line
Uri photoURI = FileProvider.getUriForFile(MainActivity.this,"com.infolabs.photu", photoFile);
.我已经将Uri photoURI = FileProvider.getUriForFile(this, "com.example.android.fileprovider",photoFile);
更改为com.infolabs.photu
,但是我无法弄明白其中有什么问题.
请查看我的代码,我具有位置URL的位置,但是由于图像为0KB,因此无法显示或工作
.I have changed Uri photoURI = FileProvider.getUriForFile(this, "com.example.android.fileprovider",photoFile);
to com.infolabs.photu
.But I can't get whats wrong in it .
Please have a look at my code and I have location URL location but It won't show or work as the image is 0KB
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
b = (Button) findViewById(R.id.captureimage);
imageView = (ImageView) findViewById(R.id.imageView);
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
if (takePictureIntent.resolveActivity(getPackageManager()) != null)
{
// Create the File where the photo should go
File photoFile = null;
try
{
photoFile = createImageFile();
Toast.makeText(MainActivity.this,mCurrentPhotoPath,Toast.LENGTH_LONG).show();
}
catch (IOException ex)
{
Toast.makeText(MainActivity.this,"the file is not created ",Toast.LENGTH_SHORT).show();
}
if (photoFile != null)
{
//this Uri does not working properly
Uri photoURI = FileProvider.getUriForFile(MainActivity.this,"com.infolabs.photu", photoFile);
takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
}
}
}
});
}
错误日志:- 致命异常:主要 流程:infolabs.photu,PID:21415 java.lang.NullPointerException:尝试在空对象引用上调用虚拟方法"android.content.res.XmlResourceParser android.content.pm.ProviderInfo.loadXmlMetaData(android.content.pm.PackageManager,java.lang.String)" 在android.support.v4.content.FileProvider.parsePathStrategy(FileProvider.java:583) 在android.support.v4.content.FileProvider.getPathStrategy(FileProvider.java:557) 在android.support.v4.content.FileProvider.getUriForFile(FileProvider.java:399) 在infolabs.photu.MainActivity $ 1.onClick(MainActivity.java:71) 在android.view.View.performClick(View.java:5269) 在android.view.View $ PerformClick.run(View.java:21556) 在android.os.Handler.handleCallback(Handler.java:815) 在android.os.Handler.dispatchMessage(Handler.java:104) 在android.os.Looper.loop(Looper.java:207) 在android.app.ActivityThread.main(ActivityThread.java:5776) 在java.lang.reflect.Method.invoke(本机方法) 在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:789) 在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:679) 04-17 16:56:15.085 21415-21425/infolabs.photu I/System:FinalizerDaemon:完成对象= 65
Error Log:- FATAL EXCEPTION: main Process: infolabs.photu, PID: 21415 java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.XmlResourceParser android.content.pm.ProviderInfo.loadXmlMetaData(android.content.pm.PackageManager, java.lang.String)' on a null object reference at android.support.v4.content.FileProvider.parsePathStrategy(FileProvider.java:583) at android.support.v4.content.FileProvider.getPathStrategy(FileProvider.java:557) at android.support.v4.content.FileProvider.getUriForFile(FileProvider.java:399) at infolabs.photu.MainActivity$1.onClick(MainActivity.java:71) at android.view.View.performClick(View.java:5269) at android.view.View$PerformClick.run(View.java:21556) at android.os.Handler.handleCallback(Handler.java:815) at android.os.Handler.dispatchMessage(Handler.java:104) at android.os.Looper.loop(Looper.java:207) at android.app.ActivityThread.main(ActivityThread.java:5776) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:789) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:679) 04-17 16:56:15.085 21415-21425/infolabs.photu I/System: FinalizerDaemon: finalize objects = 65
推荐答案
从Camera捕获图像并将其保存到sdcard:
Capture the image from Camera and save it to sdcard:
cameraBtn.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
try {
File f = createImageFile();//createImageFile() is added.
if (f != null) {
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(f));
startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
}
} catch (IOException IOE) {
IOE.printStackTrace();
}
}
});
private File createImageFile() throws IOException {
String imageFileName = "image";
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
imageFileName = imageFileName + timeStamp.toString();
File albumF = getStorageDir();
File imageF = File.createTempFile(imageFileName, ".jpg", albumF);
return imageF;
}
private File getStorageDir() {
File storageDir = null;
storageDir = new File(Environment.getExternalStorageDirectory(), "/MyApp" );
if (storageDir != null) {
if (!storageDir.mkdirs()) {
if (!storageDir.exists()) {
Log.d("CameraSample", "failed to create directory");
return null;
}
}
}
return storageDir;
}
private File getImageFile() {
String Path = Environment.getExternalStorageDirectory() + "/MyApp";
File f = new File(Path);
File imageFiles[] = f.listFiles();
if (imageFiles == null || imageFiles.length == 0) {
return null;
}
File lastModifiedFile = imageFiles[0];
for (int i = 1; i < imageFiles.length; i++) {
if (lastModifiedFile.lastModified() < imageFiles[i].lastModified()) {
lastModifiedFile = imageFiles[i];
}
}
return lastModifiedFile;
}
//从活动中覆盖方法,读取保存的图像文件并在ImageView中显示:
// overwrite the method from activity, read the save image file and show in the ImageView:
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) {
if (resultCode == RESULT_OK) {
File imageFile = getImageFile();
Bitmap bitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
mImageView.setImageBitmap(bitmap);
}}}
在清单文件中添加权限:
Add permission in the menifest file:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.CAMERA" />
这篇关于如何在位置保存图像并在Android App中将其检索为imageView?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!