Question

我正在开发一个应用程序，我必须创建一个摄像头并保存捕获的图像。我写的代码在这里：

package com.dev.camera;

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity {

    Button cambutton;
    ImageView photoImage = null;

    private static final String TAG = "CallCamera";
    private static final int CAPTURE_IMAGE_ACTIVITY_REQ = 0;

    Uri fileUri = null;
    //ImageView photoImage1 = null;

    private File getOutputPhotoFile() {

          File directory = new File(Environment.getExternalStoragePublicDirectory(
                        Environment.DIRECTORY_PICTURES), getPackageName());

          if (!directory.exists()) {
            if (!directory.mkdirs()) {
              Log.e(TAG, "Failed to create storage directory.");
              return null;
            }
          }

          String timeStamp = new SimpleDateFormat("yyyMMdd_HHmmss", Locale.US).format(new Date());

          return new File(directory.getPath() + File.separator + "IMG_"  
                            + timeStamp + ".jpg");
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Button camButton = (Button)findViewById(R.id.btncam);
        ImageView photoImage = (ImageView)findViewById(R.id.iv);

        camButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

                Intent i = new Intent (MediaStore.ACTION_IMAGE_CAPTURE);

                fileUri = Uri.fromFile(getOutputPhotoFile());
                i.putExtra(MediaStore.EXTRA_OUTPUT,fileUri);

                startActivityForResult(i, CAPTURE_IMAGE_ACTIVITY_REQ);

            }
        });

    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
          if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQ) {
            if (resultCode == RESULT_OK) {
              Uri photoUri = null;
              if (data == null) {
                // A known bug here! The image should have saved in fileUri
                Toast.makeText(this, "Image saved successfully", 
                               Toast.LENGTH_LONG).show();
                photoUri = fileUri;
              } else {
                photoUri = data.getData();
                Toast.makeText(this, "Image saved successfully in: " + data.getData(), 
                               Toast.LENGTH_LONG).show();
              }
              showPhoto(photoUri.getPath());
            } else if (resultCode == RESULT_CANCELED) {
              Toast.makeText(this, "Cancelled", Toast.LENGTH_SHORT).show();
            } else {
              Toast.makeText(this, "Callout for image capture failed!", 
                             Toast.LENGTH_LONG).show();
            }
          }
    }

    private void showPhoto(String photoUri) {
          File imageFile = new File (photoUri);
          if (imageFile.exists()){
             Bitmap bitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
             BitmapDrawable drawable = new BitmapDrawable(this.getResources(), bitmap);
             photoImage.setScaleType(ImageView.ScaleType.FIT_CENTER);
             photoImage.setImageDrawable(drawable);
          }       
    }

}

这是我用于此应用程序的xml文件。

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    tools:context="${relativePackage}.${activityClass}" 
    android:background="#858500">

    <Button 
        android:id="@+id/btncam"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="take picture"
        android:gravity="center"/>        
    <ImageView 
        android:id="@+id/iv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/button_callcamera"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="80dp"
        android:src="@drawable/ic_launcher"/>

</RelativeLayout>

当我运行此代码时，我收到一个无法创建存储目录的错误。如果有人可以帮助我，我将非常感激。 here is the screenshot of my logcat

this is the new catlog after following KALYAN's answer

Answer 1

使用此代码..我在您的文件中进行了一些更改..

package com.example.sampleapp;

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity {


Button cambutton;
ImageView photoImage = null;

private static final String TAG = "CallCamera";
private static final int CAPTURE_IMAGE_ACTIVITY_REQ = 0;

Uri fileUri = null;


private File getOutputPhotoFile() {
      File directory = new File(Environment.getExternalStoragePublicDirectory(
                    Environment.DIRECTORY_PICTURES), getPackageName());
      if (!directory.exists()) {
        if (!directory.mkdirs()) {
          Log.e(TAG, "Failed to create storage directory.");
          return null;
        }
      }
      String timeStamp = new SimpleDateFormat("yyyMMdd_HHmmss", Locale.US).format(new    Date());
      return new File(directory.getPath() + File.separator + "IMG_"  
                        + timeStamp + ".jpg");
    }

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    Button camButton = (Button)findViewById(R.id.btncam);
    photoImage = (ImageView)findViewById(R.id.iv);

    camButton.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            Intent i = new Intent (MediaStore.ACTION_IMAGE_CAPTURE);

            fileUri = Uri.fromFile(getOutputPhotoFile());
            i.putExtra(MediaStore.EXTRA_OUTPUT,fileUri);

            startActivityForResult(i, CAPTURE_IMAGE_ACTIVITY_REQ);

        }
    });

}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
      if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQ)
      {
        if (resultCode == RESULT_OK) {
          Uri photoUri = null;
          if (data == null) {
            // A known bug here! The image should have saved in fileUri
            Toast.makeText(this, "Image saved successfully",Toast.LENGTH_LONG).show();
            photoUri = fileUri;
            showPhoto(photoUri);
          } else {
            photoUri = data.getData();
            showPhoto(photoUri);
            Toast.makeText(this, "Image saved successfully in: " + data.getData(), 
                           Toast.LENGTH_LONG).show();
          }

        } else if (resultCode == RESULT_CANCELED) {
          Toast.makeText(this, "Cancelled", Toast.LENGTH_SHORT).show();
        } else {
          Toast.makeText(this, "Callout for image capture failed!", 
                         Toast.LENGTH_LONG).show();
        }
      }
}

private void showPhoto(Uri photoUri) {
      File imageFile = new File(photoUri.getPath());
      if (imageFile.exists()){
         Bitmap bitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
         BitmapDrawable drawable = new BitmapDrawable(this.getResources(), bitmap);
         photoImage.setScaleType(ImageView.ScaleType.FIT_CENTER);
         photoImage.setImageDrawable(drawable);
      }       
    }
}

这是你的xml文件：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:context="${relativePackage}.${activityClass}" 
android:background="#858500">



<Button 
    android:id="@+id/btncam"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="take picture"
    android:gravity="center"/>

<ImageView 
    android:id="@+id/iv"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/btncam"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="80dp"
    android:src="@drawable/ic_launcher"/>

</RelativeLayout>

将这些权限添加到清单文件：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

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1 个答案: