Java android应用程序在切换到同一文件中的其他方法后崩溃_Java_Android_Android Activity

Java android应用程序在切换到同一文件中的其他方法后崩溃

java android

Java android应用程序在切换到同一文件中的其他方法后崩溃,java,android,android-activity,Java,Android,Android Activity,这是一个我为练习相机活动而创建的练习应用程序。我是Android Studio和Android开发的新手，所以在评论时请记住这一点。该应用程序很简单，点击一个按钮，就会出现三个选项（拍照、从库中选择、取消）。我可以拍一张照片，然后再次点击按钮，再拍一张照片，然后从库中进行选择。我的问题是，当我从拍照切换到选择照片时，应用程序崩溃。我也使用在线教程创建了这段代码。下面是我的MainActivity.java、Utility.java和应用程序清单。提前谢谢你的帮助 MainActivity.jav

这是一个我为练习相机活动而创建的练习应用程序。我是Android Studio和Android开发的新手，所以在评论时请记住这一点。该应用程序很简单，点击一个按钮，就会出现三个选项（拍照、从库中选择、取消）。我可以拍一张照片，然后再次点击按钮，再拍一张照片，然后从库中进行选择。我的问题是，当我从拍照切换到选择照片时，应用程序崩溃。我也使用在线教程创建了这段代码。下面是我的MainActivity.java、Utility.java和应用程序清单。提前谢谢你的帮助

MainActivity.java

package com.example.myfirstapp;

import android.app.Activity;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import com.squareup.picasso.Picasso;

public class MainActivity extends AppCompatActivity {

private int REQUEST_CAMERA = 0, SELECT_FILE = 1;
private Button btnSelect;
private ImageView ivImage;
private String userChoosenTask;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    btnSelect = (Button) findViewById(R.id.btnSelectPhoto);
    btnSelect.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            selectImage();
        }
    });
    ivImage = (ImageView) findViewById(R.id.ivImage);
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    switch (requestCode) {
        case com.example.myfirstapp.Utility.MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                if(userChoosenTask.equals("Take Photo"))
                    cameraIntent();
                else if(userChoosenTask.equals("Choose from Library"))
                    galleryIntent();
            } else {
                //code for deny
            }
            break;
    }
}

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) {
            boolean result=com.example.myfirstapp.Utility.checkPermission(MainActivity.this);

            if (items[item].equals("Take Photo")) {
                userChoosenTask ="Take Photo";
                if(result)
                    cameraIntent();

            } else if (items[item].equals("Choose from Library")) {
                userChoosenTask ="Choose from Library";
                if(result)
                    galleryIntent();

            } else if (items[item].equals("Cancel")) {
                dialog.dismiss();
            }
        }
    });
    builder.show();
}

private void galleryIntent()
{
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);//
    startActivityForResult(Intent.createChooser(intent, "Select File"),SELECT_FILE);
}

private void cameraIntent()
{
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    startActivityForResult(intent, REQUEST_CAMERA);
}

@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();
    }
    Bitmap bm=null;
    //grab recently taken image from gallery
    try {
        bm = MediaStore.Images.Media.getBitmap(getApplicationContext().getContentResolver(), data.getData());
    } catch (IOException e) {
        e.printStackTrace();
    }
    ivImage.setImageBitmap(bm);
    ivImage.setRotation(90);
}

@SuppressWarnings("deprecation")
private void onSelectFromGalleryResult(Intent data) {

    Bitmap bm=null;
    if (data != null) {
        try {
            bm = MediaStore.Images.Media.getBitmap(getApplicationContext().getContentResolver(), data.getData());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    ivImage.setImageBitmap(bm);
    ivImage.setRotation(90);
}

}

package com.example.myfirstapp;

    import android.Manifest;
    import android.annotation.TargetApi;
    import android.app.Activity;
    import android.content.Context;
    import android.content.DialogInterface;
    import android.content.pm.PackageManager;
    import android.os.Build;
    import android.support.v4.app.ActivityCompat;
    import android.support.v4.content.ContextCompat;
    import android.support.v7.app.AlertDialog;

public class Utility {
public static final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE = 
123;

@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
public static boolean checkPermission(final Context context)
{
    int currentAPIVersion = Build.VERSION.SDK_INT;
    if(currentAPIVersion>=android.os.Build.VERSION_CODES.M)
    {
        if (ContextCompat.checkSelfPermission(context, 
Manifest.permission.READ_EXTERNAL_STORAGE) != 
PackageManager.PERMISSION_GRANTED) {
            if 
(ActivityCompat.shouldShowRequestPermissionRationale((Activity) 
context, 
Manifest.permission.READ_EXTERNAL_STORAGE)) {
                AlertDialog.Builder alertBuilder = new 
AlertDialog.Builder(context);
                alertBuilder.setCancelable(true);
                alertBuilder.setTitle("Permission necessary");
                alertBuilder.setMessage("External storage permission is 
necessary");
                alertBuilder.setPositiveButton(android.R.string.yes, 
new DialogInterface.OnClickListener() {
                    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
                    public void onClick(DialogInterface dialog, int 
which) {
                        ActivityCompat.requestPermissions((Activity) 
context, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 
MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
                    }
                });
                AlertDialog alert = alertBuilder.create();
                alert.show();

            } else {
                ActivityCompat.requestPermissions((Activity) context, 
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 
MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
            }
            return false;
        } else {
            return true;
        }
    } else {
        return true;
    }
}
}

Utility.java

package com.example.myfirstapp;

import android.app.Activity;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import com.squareup.picasso.Picasso;

public class MainActivity extends AppCompatActivity {

private int REQUEST_CAMERA = 0, SELECT_FILE = 1;
private Button btnSelect;
private ImageView ivImage;
private String userChoosenTask;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    btnSelect = (Button) findViewById(R.id.btnSelectPhoto);
    btnSelect.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            selectImage();
        }
    });
    ivImage = (ImageView) findViewById(R.id.ivImage);
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    switch (requestCode) {
        case com.example.myfirstapp.Utility.MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                if(userChoosenTask.equals("Take Photo"))
                    cameraIntent();
                else if(userChoosenTask.equals("Choose from Library"))
                    galleryIntent();
            } else {
                //code for deny
            }
            break;
    }
}

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) {
            boolean result=com.example.myfirstapp.Utility.checkPermission(MainActivity.this);

            if (items[item].equals("Take Photo")) {
                userChoosenTask ="Take Photo";
                if(result)
                    cameraIntent();

            } else if (items[item].equals("Choose from Library")) {
                userChoosenTask ="Choose from Library";
                if(result)
                    galleryIntent();

            } else if (items[item].equals("Cancel")) {
                dialog.dismiss();
            }
        }
    });
    builder.show();
}

private void galleryIntent()
{
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);//
    startActivityForResult(Intent.createChooser(intent, "Select File"),SELECT_FILE);
}

private void cameraIntent()
{
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    startActivityForResult(intent, REQUEST_CAMERA);
}

@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();
    }
    Bitmap bm=null;
    //grab recently taken image from gallery
    try {
        bm = MediaStore.Images.Media.getBitmap(getApplicationContext().getContentResolver(), data.getData());
    } catch (IOException e) {
        e.printStackTrace();
    }
    ivImage.setImageBitmap(bm);
    ivImage.setRotation(90);
}

@SuppressWarnings("deprecation")
private void onSelectFromGalleryResult(Intent data) {

    Bitmap bm=null;
    if (data != null) {
        try {
            bm = MediaStore.Images.Media.getBitmap(getApplicationContext().getContentResolver(), data.getData());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    ivImage.setImageBitmap(bm);
    ivImage.setRotation(90);
}

}

package com.example.myfirstapp;

    import android.Manifest;
    import android.annotation.TargetApi;
    import android.app.Activity;
    import android.content.Context;
    import android.content.DialogInterface;
    import android.content.pm.PackageManager;
    import android.os.Build;
    import android.support.v4.app.ActivityCompat;
    import android.support.v4.content.ContextCompat;
    import android.support.v7.app.AlertDialog;

public class Utility {
public static final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE = 
123;

@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
public static boolean checkPermission(final Context context)
{
    int currentAPIVersion = Build.VERSION.SDK_INT;
    if(currentAPIVersion>=android.os.Build.VERSION_CODES.M)
    {
        if (ContextCompat.checkSelfPermission(context, 
Manifest.permission.READ_EXTERNAL_STORAGE) != 
PackageManager.PERMISSION_GRANTED) {
            if 
(ActivityCompat.shouldShowRequestPermissionRationale((Activity) 
context, 
Manifest.permission.READ_EXTERNAL_STORAGE)) {
                AlertDialog.Builder alertBuilder = new 
AlertDialog.Builder(context);
                alertBuilder.setCancelable(true);
                alertBuilder.setTitle("Permission necessary");
                alertBuilder.setMessage("External storage permission is 
necessary");
                alertBuilder.setPositiveButton(android.R.string.yes, 
new DialogInterface.OnClickListener() {
                    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
                    public void onClick(DialogInterface dialog, int 
which) {
                        ActivityCompat.requestPermissions((Activity) 
context, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 
MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
                    }
                });
                AlertDialog alert = alertBuilder.create();
                alert.show();

            } else {
                ActivityCompat.requestPermissions((Activity) context, 
new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 
MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
            }
            return false;
        } else {
            return true;
        }
    } else {
        return true;
    }
}
}

Android清单

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.myfirstapp">

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

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" 
/>
        </intent-filter>
    </activity>
</application>

</manifest>

你能发布崩溃日志吗？我的调试器工作不正常，所以日志中没有出现任何问题。在这里发布之前，我打算先查看一下…Android监视器应该显示您的崩溃日志，而不是调试器。我建议先让它工作。感谢您的建议，它现在正在工作，我发布了崩溃日志。您的Android设备在尝试加载

位图时内存不足，崩溃日志中的OutOfMemoryError指出了这一点。这是Android中的一个常见问题，有许多在线解决方案。有关解决方案，请参阅：