当不选择裁剪图像应用程序时，阻止应用程序崩溃-Android

debugcn 发表于 Dev

用户名

我有一个可以从图库或相机中裁剪图像的应用程序。除了一个小功能，它工作得非常好。当我从图库中选择图像时，它会问我要使用哪种裁切应用程序来裁切图像，但是如果我在布局框外单击或按“后退”按钮，则整个应用程序将崩溃。如何使应用程序不崩溃？

这是我的主要活动

package com.goboapp;

import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.ActivityNotFoundException;
import android.content.ComponentName;
import android.content.Context;
import android.content.ContextWrapper;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.ResolveInfo;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import com.loopj.android.http.RequestParams;


public class Main extends ActionBarActivity {
    private Uri mImageCaptureUri;

    private static final int PICK_FROM_CAMERA = 1;
    private static final int CROP_FROM_CAMERA = 2;
    private static final int PICK_FROM_FILE = 3;

     ImageView imageView1;
     RoundImage roundedImage;
     Bitmap bitmap;
     ProgressDialog prgDialog;
     String encodedString;
     RequestParams params = new RequestParams();
     String imgPath, fileName;
     Bitmap bitmap2;
     TextView tv;
     String uploadFilePath;
     String uploadFileName;


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

        //SET VIEWS
        imageView1 = (ImageView) findViewById(R.id.imageView1);
        tv = (TextView) findViewById(R.id.tv);


        //CAMERA STUFF

        final String [] items           = new String [] {"Take from camera", "Select from gallery"};                
        ArrayAdapter<String> adapter    = new ArrayAdapter<String> (this, android.R.layout.select_dialog_item,items);
        AlertDialog.Builder builder     = new AlertDialog.Builder(this);

        builder.setTitle("Select Image");
        builder.setAdapter( adapter, new DialogInterface.OnClickListener() {
            public void onClick( DialogInterface dialog, int item ) { //pick from camera
                if (item == 0) {
                    Intent intent    = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

                    mImageCaptureUri = Uri.fromFile(new File(Environment.getExternalStorageDirectory(),
                                       "tmp_avatar_" + String.valueOf(System.currentTimeMillis()) + ".jpg"));

                    intent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, mImageCaptureUri);

                    try {
                        intent.putExtra("return-data", true);

                        startActivityForResult(intent, PICK_FROM_CAMERA);
                    } catch (ActivityNotFoundException e) {
                        e.printStackTrace();
                    }
                } else { //pick from file
                    Intent i = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                    startActivityForResult(i, PICK_FROM_FILE);

                }
            }
        } );

        final AlertDialog dialog = builder.create();

        Button button   = (Button) findViewById(R.id.btn_crop);

        button.setOnClickListener(new View.OnClickListener() {  
            @Override
            public void onClick(View v) {
                dialog.show();
            }
        });

        //END END END CAMERA STUFF


         }// End OnCreate



    @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;
    }//end onCreateOptionsMenu

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }//end onOptionsItemSelected



    //CAMERA STUFF

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode != RESULT_OK) return;

        switch (requestCode) {
            case PICK_FROM_CAMERA:
                doCrop();

                break;

            case PICK_FROM_FILE: 
                mImageCaptureUri = data.getData();

                doCrop();

                break;          

            case CROP_FROM_CAMERA:          
                Bundle extras = data.getExtras();

                if (extras != null) {               
                    Bitmap photo = extras.getParcelable("data");

                   imageView1.setImageBitmap(photo);


                }

                File f = new File(mImageCaptureUri.getPath());            

                if (f.exists()) f.delete();

                break;

        }
    }



    //CROP IMAGE

      private void doCrop() {
        final ArrayList<CropOption> cropOptions = new ArrayList<CropOption>();

        Intent intent = new Intent("com.android.camera.action.CROP");
          intent.setType("image/*");

          List<ResolveInfo> list = getPackageManager().queryIntentActivities( intent, 0 );

          int size = list.size();

          if (size == 0) {          
            Toast.makeText(this, "Can not find image crop app", Toast.LENGTH_SHORT).show();

              return;
          } else {
            intent.setData(mImageCaptureUri);

              intent.putExtra("outputX", 200);
              intent.putExtra("outputY", 200);
              intent.putExtra("aspectX", 1);
              intent.putExtra("aspectY", 1);
              intent.putExtra("scale", true);
              intent.putExtra("return-data", true);

            if (size == 1) {
                Intent i        = new Intent(intent);
                ResolveInfo res = list.get(0);

                i.setComponent( new ComponentName(res.activityInfo.packageName, res.activityInfo.name));

                startActivityForResult(i, CROP_FROM_CAMERA);
            } else {
                for (ResolveInfo res : list) {
                    final CropOption co = new CropOption();

                    co.title    = getPackageManager().getApplicationLabel(res.activityInfo.applicationInfo);
                    co.icon     = getPackageManager().getApplicationIcon(res.activityInfo.applicationInfo);
                    co.appIntent= new Intent(intent);

                    co.appIntent.setComponent( new ComponentName(res.activityInfo.packageName, res.activityInfo.name));

                    cropOptions.add(co);
                }

                CropOptionAdapter adapter = new CropOptionAdapter(getApplicationContext(), cropOptions);

                AlertDialog.Builder builder = new AlertDialog.Builder(this);
                builder.setTitle("Choose Crop App");
                builder.setAdapter( adapter, new DialogInterface.OnClickListener() {
                    public void onClick( DialogInterface dialog, int item ) {
                        startActivityForResult( cropOptions.get(item).appIntent, CROP_FROM_CAMERA);
                    }
                });

                builder.setOnCancelListener( new DialogInterface.OnCancelListener() {
                    @Override
                    public void onCancel( DialogInterface dialog ) {

                        if (mImageCaptureUri != null ) {
                            getContentResolver().delete(mImageCaptureUri, null, null );
                            mImageCaptureUri = null;
                        }
                    }
                } );

                AlertDialog alert = builder.create();

                alert.show();
            }
          }
    }

      //END END END CROP IMAGE





}//end activity

这是CropOptionAdapter.java

package com.goboapp;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import android.content.Context;

import java.util.ArrayList;

public class CropOptionAdapter extends ArrayAdapter<CropOption> {
    private ArrayList<CropOption> mOptions;
    private LayoutInflater mInflater;

    public CropOptionAdapter(Context context, ArrayList<CropOption> options) {
        super(context, R.layout.crop_selector, options);

        mOptions    = options;

        mInflater   = LayoutInflater.from(context);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup group) {
        if (convertView == null)
            convertView = mInflater.inflate(R.layout.crop_selector, null);

        CropOption item = mOptions.get(position);

        if (item != null) {
            ((ImageView) convertView.findViewById(R.id.iv_icon)).setImageDrawable(item.icon);
            ((TextView) convertView.findViewById(R.id.tv_name)).setText(item.title);

            return convertView;
        }

        return null;
    }
}

这是CropOption.java

package com.goboapp;

import android.content.Intent;
import android.graphics.drawable.Drawable;

public class CropOption {
    public CharSequence title;
    public Drawable icon;
    public Intent appIntent;
}

这是crop_selector.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="10dp"
    android:gravity="center_vertical">

    <ImageView
        android:id="@+id/iv_icon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

    <TextView
        android:id="@+id/tv_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text=""/>
</LinearLayout>

这是LogCat

11-17 20:17:15.708: E/AndroidRuntime(23829): FATAL EXCEPTION: main
11-17 20:17:15.708: E/AndroidRuntime(23829): Process: com.goboapp, PID: 23829
11-17 20:17:15.708: E/AndroidRuntime(23829): java.lang.SecurityException: Permission Denial: writing com.android.providers.media.MediaProvider uri content://media/external/images/media/1448 from pid=23829, uid=10168 requires android.permission.WRITE_EXTERNAL_STORAGE, or grantUriPermission()
11-17 20:17:15.708: E/AndroidRuntime(23829):    at android.os.Parcel.readException(Parcel.java:1471)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:185)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:137)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at android.content.ContentProviderProxy.delete(ContentProviderNative.java:536)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at android.content.ContentResolver.delete(ContentResolver.java:1282)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at com.goboapp.Main$5.onCancel(Main.java:340)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at android.app.Dialog$ListenersHandler.handleMessage(Dialog.java:1241)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at android.os.Handler.dispatchMessage(Handler.java:102)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at android.os.Looper.loop(Looper.java:136)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at android.app.ActivityThread.main(ActivityThread.java:5097)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at java.lang.reflect.Method.invokeNative(Native Method)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at java.lang.reflect.Method.invoke(Method.java:515)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
11-17 20:17:15.708: E/AndroidRuntime(23829):    at dalvik.system.NativeStart.main(Native Method)

我从主要活动中省略了一些不相关的功能。我也想知道是否有可能强迫用户使用默认的作物应用程序而不是要求他们选择。我遵循了获得此代码的教程，这就是为什么我不知道如何做到这一点的原因。

奥斯汀·马奥尼（Austyn Mahoney）

您的应用缺少权限android.permission.WRITE_EXTERNAL_STORAGE。

我认为裁剪照片需要能够写入磁盘，因为它正在使用MediaProvider内容提供程序。

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