我的应用程序是打开内置相机并将其保存到 sd 卡中，然后启动一个新活动并在其上预览捕获的图像。
这是启动新的 AsynTask 以打开相机的 loginActivity ：
package com.android.grad;
import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;
import com.Camera.R;
public class LoginActivity extends Activity {
private final int MEDIA_TYPE_IMAGE = 1;
private CheckBox rememberMe;
private EditText userName, passWord;
private Button loginBtn;
private final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100;
private String path;
private Uri fileUri;
private OnClickListener loginOnClick = new OnClickListener() {
public void onClick(View v) {
new LoginTask(LoginActivity.this, fileUri).execute();
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE);
path = fileUri.getPath();
loginBtn = (Button) findViewById(R.id.signInBtn);
loginBtn.setOnClickListener(loginOnClick);
rememberMe = (CheckBox) findViewById(R.id.keepMe);
userName = (EditText) findViewById(R.id.userNameID);
passWord = (EditText) findViewById(R.id.passwordID);
}
@Override
protected void onResume() {
super.onResume();
SharedPreferences sp = getSharedPreferences("user", MODE_PRIVATE);
try {
userName.setText(sp.getString("username", ""));
passWord.setText(sp.getString("password", ""));
rememberMe.setChecked(sp.getBoolean("rememberMe", false));
} catch (ClassCastException ex) {
}
}
@Override
protected void onPause() {
super.onPause();
SharedPreferences sp = getSharedPreferences("user", MODE_PRIVATE);
Editor editor = sp.edit();
if (rememberMe.isChecked()) {
editor.putString("username", userName.getText().toString());
editor.putString("password", passWord.getText().toString());
} else {
editor.putString("username", "");
editor.putString("password", "");
}
editor.putBoolean("rememberMe", rememberMe.isChecked());
editor.commit();
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) {
if (resultCode == RESULT_OK) {
Intent intent = new Intent(LoginActivity.this,
PreviewActivity.class);
intent.putExtra("path", path);
startActivity(intent);
} else if (resultCode == RESULT_CANCELED) {
// User cancelled the image capture
Toast.makeText(getApplicationContext(),
"User cancelled the image capture", Toast.LENGTH_LONG)
.show();
} else {
// Image capture failed, advise user
}
}
}
/** Create a file Uri for saving an image or video */
private Uri getOutputMediaFileUri(int type) {
File f = getOutputMediaFile(type);
if (f == null) {
Toast.makeText(LoginActivity.this, "MyCameraApp File not found",
Toast.LENGTH_LONG);
return null;
}
return Uri.fromFile(f);
}
/** Create a File for saving an image or video */
private File getOutputMediaFile(int type) {
// Check if SD card is mounted
if (Environment.getExternalStorageState().equals(
Environment.MEDIA_MOUNTED)) {
File externalFilesDir = LoginActivity.this
.getExternalFilesDir(Environment.DIRECTORY_PICTURES);
File outFile = new File(externalFilesDir, "IDOCR");
if (!outFile.exists())
outFile.mkdirs();
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
.format(new Date());
String path = outFile.getPath() + File.separator + "IMG"
+ timeStamp + ".jpg";
File mediaFile = new File(path);
return mediaFile;
}
Toast.makeText(LoginActivity.this, "SD card unmounted",
Toast.LENGTH_LONG);
return null;
}
}
这是 AsynTask :-
package com.android.grad;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.net.Uri;
import android.os.AsyncTask;
import android.provider.MediaStore;
public class LoginTask extends AsyncTask<Void, Void, Boolean> {
private Activity activity;
private ProgressDialog pd;
private Uri fileUri;
private final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100;
public LoginTask(Activity activity, Uri fileUri) {
this.activity = activity;
this.fileUri = fileUri;
}
@Override
protected void onPreExecute() {
pd = ProgressDialog.show(activity, "Signing in",
"Please wait while we are signing you in..");
}
@Override
protected Boolean doInBackground(Void... arg0) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
}
return true;
}
@Override
protected void onPostExecute(Boolean result) {
pd.dismiss();
pd = null;
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
activity.startActivityForResult(intent,
CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
}
}
这是previewActivity：-
package com.android.grad;
import java.io.File;
import java.io.IOException;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import com.Camera.R;
import com.OCR.ID.AndroidImage;
import com.OCR.ID.Segement;
public class PreviewActivity extends Activity {
private ImageView previewIV;
private final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100;
private String path;
private boolean crop = true;
private boolean resample = true;
private ProgressDialog pd;
OnClickListener processOnClickListener = new OnClickListener() {
public void onClick(View v) {
try {
createProgressDialog();
pd.show();
new Segement(PreviewActivity.this, pd).execute(path);
} catch (IOException e) {
}
}
};
private void createProgressDialog() {
pd = new ProgressDialog(PreviewActivity.this);
pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
pd.setTitle("Extract ID");
pd.setMessage("Processing...");
pd.setIcon(R.drawable.ic_launcher);
pd.setProgress(0);
pd.setCancelable(false);
}
private OnClickListener backOnClickListener = new OnClickListener() {
public void onClick(View v) {
startActivityForResult(
new Intent(MediaStore.ACTION_IMAGE_CAPTURE).putExtra(
MediaStore.EXTRA_OUTPUT,
Uri.fromFile(new File(path))),
CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
}
};
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) {
previewIV.setImageBitmap(BitmapFactory.decodeFile(path));
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.preview);
path = getIntent().getExtras().getString("path");
previewIV = (ImageView) findViewById(R.id.previewPicID);
previewIV.setImageBitmap(AndroidImage.decodeSampledBitmapFromSDcard(
path, 150, 150));
// previewIV.setImageBitmap(AndroidImage.readImage(path));
Button process = (Button) findViewById(R.id.processID);
process.setOnClickListener(processOnClickListener);
Button back = (Button) findViewById(R.id.back);
back.setOnClickListener(backOnClickListener);
}
}
有时拍照时出现在previewActivity中有时不出现的错误？
为什么会出现这个错误？？