android - 在图像上单击在另一个 Activity 中打开图像

Question

我有一个 imageView，其中的图像是从 url 加载的。单击图像时，我想在另一个包含自定义 View 的 Activity 中显示图像。当我点击图像时出现错误并且 Activity 崩溃。

Main2Activity

public class Main2Activity extends AppCompatActivity {

    ImageView imageView;
    ImageLoader imgLoader;
    String strURL = "http://static.ddmcdn.com/gif/cats-250-250.jpg";
   // URI uri = null;
   // URL url = null;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);


        imageView = (ImageView) findViewById(R.id.imageView2);

        imgLoader = new ImageLoader(this);

        imgLoader.DisplayImage(strURL, imageView);

        imageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {


                Intent i = new Intent(Main2Activity.this, MemeCreateActivity.class);
                i.putExtra(MemeCreateActivity.EXTRA_IMAGE_PATH, strURL);
                startActivity(i);
            }
        });


}
}

MemeCreateActivity

public class MemeCreateActivity extends AppCompatActivity
        implements MemeSetting.OnMemeSettingChangedListener<Typeface, Bitmap>,
        BottomSheetLayout.OnSheetStateChangeListener, OnSheetDismissedListener {
    //########################
    //## Static
    //########################
    public final static int RESULT_MEME_EDITING_FINISHED = 150;
    public final static int RESULT_MEME_EDIT_SAVED = 1;
    public final static int RESULT_MEME_NOT_SAVED = 0;
    public final static String EXTRA_IMAGE_PATH = "extraImage";
    public final static String ASSET_IMAGE = "assetImage";


    //########################
    //## UI Binding
    //########################
    @BindView(R.id.fab)
    FloatingActionButton fab;

    @BindView(R.id.toolbar)
    Toolbar toolbar;

    @BindView(R.id.memecreate__activity__bottomsheet_layout)
    BottomSheetLayout bottomSheet;

    @BindView(R.id.memecreate__activity__image)
    ImageView imageEditView;

    @BindView(R.id.memecreate__activity__edit_caption_bottom)
    EditText textEditBottomCaption;

    @BindView(R.id.memecreate__activity__edit_caption_top)
    EditText textEditTopCaption;

    //#####################
    //## Members
    //#####################
    private static boolean doubleBackToExitPressedOnce = false;
    private Bitmap lastBitmap = null;
    private long memeSavetime = -1;
    private App app;
    private MemeSetting<Typeface, Bitmap> memeSetting;
    private boolean bFullscreenImage = true;

    //#####################
    //## Methods
    //#####################
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.memecreate__activity);

        // Quit activity if no image was given
        Intent intent = getIntent();
        String action = intent.getAction();
        String type = intent.getType();
        if (!(Intent.ACTION_SEND.equals(action) && type.startsWith("image/")) &&
                (!getIntent().hasExtra(EXTRA_IMAGE_PATH) || !getIntent().hasExtra(ASSET_IMAGE))) {
            finish();
            return;
        }

        // Bind Ui
        ButterKnife.bind(this);
        app = (App) getApplication();

        // Set toolbar
        setSupportActionBar(toolbar);
        if (getSupportActionBar() != null) {
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        }


        Bitmap bitmap = extractBitmapFromIntent(intent);
        memeSetting = new MemeSetting<>(app.getFonts().get(app.settings.getLastSelectedFont()), bitmap);
        memeSetting.setDisplayImage(memeSetting.getImage().copy(Bitmap.Config.RGB_565, false));
        memeSetting.setFontId(app.settings.getLastSelectedFont());

        textEditTopCaption.setText(memeSetting.getCaptionTop());
        textEditBottomCaption.setText(memeSetting.getCaptionBottom());

        memeSetting.setMemeSettingChangedListener(this);
        memeSetting.notifyChangedListener();

    }

    @Override
    protected void onDestroy() {
        imageEditView.setImageBitmap(null);
        if (lastBitmap != null && !lastBitmap.isRecycled())
            lastBitmap.recycle();
        if (!memeSetting.getImage().isRecycled())
            memeSetting.getImage().recycle();
        if (!memeSetting.getDisplayImage().isRecycled())
            memeSetting.getDisplayImage().recycle();
        super.onDestroy();
    }

    @Override
    protected void onResume() {
        super.onResume();
        if (bFullscreenImage) {
            bFullscreenImage = false;
            overridePendingTransition(R.anim.fadein, R.anim.fadeout);
        }
    }

    private Bitmap extractBitmapFromIntent(final Intent intent) {
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        Bitmap bitmap = null;
        String imagePath = getIntent().getStringExtra(EXTRA_IMAGE_PATH);
        App.log("imagepath::" + imagePath);
        if (intent.getAction() != null && intent.getAction().equals(Intent.ACTION_SEND) && intent.getType().startsWith("image/")) {
            Uri imageURI = intent.getParcelableExtra(Intent.EXTRA_STREAM);
            if (imageURI != null) {
                try {
                    bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), imageURI);
                } catch (IOException e) {
                    bitmap = null;
                    e.printStackTrace();
                }
            }
        } else if (intent.getBooleanExtra(ASSET_IMAGE, false)) {
            try {
                //Scale big images down to avoid "out of memory"
                InputStream inputStream = getAssets().open(imagePath);
                BitmapFactory.decodeStream(inputStream, new Rect(0, 0, 0, 0), options);
                options.inSampleSize = Helpers.calculateInSampleSize(options, app.settings.getRenderQuality());
                options.inJustDecodeBounds = false;
                inputStream.close();
                inputStream = getAssets().open(imagePath);
                bitmap = BitmapFactory.decodeStream(inputStream, new Rect(0, 0, 0, 0), options);
            } catch (IOException e) {
                bitmap = null;
                e.printStackTrace();
            }
        } else {
            //Scale big images down to avoid "out of memory"
            BitmapFactory.decodeFile(imagePath, options);
            options.inSampleSize = Helpers.calculateInSampleSize(options, app.settings.getRenderQuality());
            options.inJustDecodeBounds = false;
            bitmap = BitmapFactory.decodeFile(imagePath, options);
        }
        return bitmap;
    }

    @Override
    public void onBackPressed() {
        if (bottomSheet.isSheetShowing()) {
            bottomSheet.dismissSheet();
            return;
        }
        if (doubleBackToExitPressedOnce) {
            super.onBackPressed();
            return;
        }
        doubleBackToExitPressedOnce = true;
        Snackbar.make(findViewById(android.R.id.content), R.string.creator__press_back_again_to_exit, Snackbar.LENGTH_SHORT).show();
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                doubleBackToExitPressedOnce = false;
            }
        }, 2000);
    }

    @OnClick(R.id.memecreate__activity__image)
    public void onImageClicked(View view) {
        Helpers.hideSoftKeyboard(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.creatememe__menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.action_share: {
                app.shareBitmapToOtherApp(lastBitmap, this);
                return true;
            }
            case R.id.action_save: {
                saveMemeToFilesystem();
                return true;
            }
        }
        return super.onOptionsItemSelected(item);
    }

    private void saveMemeToFilesystem() {
        String filepath = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), getString(R.string.app_name)).getAbsolutePath();
        String thumbnailPath = new File(filepath, getString(R.string.dot_thumbnails)).getAbsolutePath();
        if (memeSavetime < 0) {
            memeSavetime = System.currentTimeMillis();
        }

        String filename = String.format(Locale.getDefault(), "%s_%d.jpg", getString(R.string.app_name), memeSavetime);
        if (Helpers.saveBitmapToFile(filepath, filename, lastBitmap) != null && Helpers.saveBitmapToFile(thumbnailPath, filename, Helpers.createThumbnail(lastBitmap)) != null) {
            AlertDialog.Builder dialog = new AlertDialog.Builder(this);
            dialog.setTitle(R.string.creator__saved_successfully)
                    .setMessage(R.string.creator__saved_successfully_message)
                    .setNegativeButton(android.R.string.no, null)
                    .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {
                            finish();
                        }
                    });
            dialog.show();
        }
    }

    @OnClick(R.id.fab)
    public void onFloatingButtonClicked(View view) {
        fab.setVisibility(View.INVISIBLE);
        bottomSheet.showWithSheetView(((LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE)).
                inflate(R.layout.memecreate__bottom_sheet, bottomSheet, false));
        bottomSheet.addOnSheetStateChangeListener(this);
        bottomSheet.addOnSheetDismissedListener(this);

        LineColorPicker colorPickerShade = ButterKnife.findById(this, R.id.memecreate__bottom_sheet__color_picker_for_border);
        LineColorPicker colorPickerText = ButterKnife.findById(this, R.id.memecreate__bottom_sheet__color_picker_for_text);
        Spinner dropdownFont = ButterKnife.findById(this, R.id.memecreate__bottom_sheet__dropdown_font);
        SeekBar seekFontSize = ButterKnife.findById(this, R.id.memecreate__bottom_sheet__seek_font_size);
        ToggleButton toggleAllCaps = ButterKnife.findById(this, R.id.memecreate__bottom_sheet__toggle_all_caps);

        colorPickerText.setColors(MemeLibConfig.MEME_COLORS.ALL);
        colorPickerShade.setColors(MemeLibConfig.MEME_COLORS.ALL);

        FontAdapter adapter = new FontAdapter(
                this, android.R.layout.simple_list_item_1, app.getFonts());
        dropdownFont.setAdapter(adapter);


        // Apply existing settings
        colorPickerText.setSelectedColor(memeSetting.getTextColor());
        colorPickerShade.setSelectedColor(memeSetting.getBorderColor());
        dropdownFont.setSelection(memeSetting.getFontId());
        toggleAllCaps.setChecked(memeSetting.isAllCaps());
        ((SeekBar) ButterKnife.findById(this, R.id.memecreate__bottom_sheet__seek_font_size)).setProgress(memeSetting.getFontSize() - MemeLibConfig.FONT_SIZES.MIN);

        //
        //  Add bottom sheet listeners
        //
        colorPickerShade.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                LineColorPicker picker = (LineColorPicker) v;
                memeSetting.setBorderColor(picker.getColor());
            }
        });
        colorPickerText.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                LineColorPicker picker = (LineColorPicker) v;
                memeSetting.setTextColor(picker.getColor());
            }
        });
        dropdownFont.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            public void onNothingSelected(AdapterView<?> parent) {
            }

            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                memeSetting.setFont((MemeFont<Typeface>) parent.getSelectedItem());
                memeSetting.setFontId(parent.getSelectedItemPosition());
                app.settings.setLastSelectedFont(memeSetting.getFontId());
            }
        });
        seekFontSize.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            public void onStartTrackingTouch(SeekBar seekBar) {
            }

            public void onStopTrackingTouch(SeekBar seekBar) {
            }

            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                memeSetting.setFontSize(progress + MemeLibConfig.FONT_SIZES.MIN);
            }
        });
        toggleAllCaps.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                memeSetting.setAllCaps(isChecked);
            }
        });
    }

    public Bitmap drawMultilineTextToBitmap(Context c, MemeSetting<Typeface, Bitmap> memeSetting) {
        // prepare canvas
        Resources resources = c.getResources();
        Bitmap bitmap = memeSetting.getDisplayImage();

        float scale = Helpers.getScalingFactor(bitmap.getWidth(), bitmap.getHeight());
        float borderScale = scale * memeSetting.getFontSize() / MemeLibConfig.FONT_SIZES.DEFAULT;
        Bitmap.Config bitmapConfig = bitmap.getConfig();
        // set default bitmap config if none
        if (bitmapConfig == null) {
            bitmapConfig = Bitmap.Config.RGB_565;
        }
        // resource bitmaps are immutable,
        // so we need to convert it to mutable one
        bitmap = bitmap.copy(bitmapConfig, true);
        Canvas canvas = new Canvas(bitmap);

        // new antialiased Paint
        TextPaint paint = new TextPaint(Paint.ANTI_ALIAS_FLAG);
        paint.setTextSize((int) (memeSetting.getFontSize() * scale));
        paint.setTypeface(memeSetting.getFont().getFont());
        //paint.setStrokeWidth(memeSetting.getFontSize() / 4);
        paint.setStrokeWidth(borderScale);

        String[] textStrings = {memeSetting.getCaptionTop(), memeSetting.getCaptionBottom()};
        if (memeSetting.isAllCaps()) {
            for (int i = 0; i < textStrings.length; i++) {
                textStrings[i] = textStrings[i].toUpperCase();
            }
        }

        for (int i = 0; i < textStrings.length; i++) {
            paint.setColor(memeSetting.getBorderColor());
            paint.setStyle(Paint.Style.FILL_AND_STROKE);

            // set text width to canvas width minus 16dp padding
            int textWidth = canvas.getWidth() - (int) (16 * scale);

            // init StaticLayout for text
            StaticLayout textLayout = new StaticLayout(
                    textStrings[i], paint, textWidth, Layout.Alignment.ALIGN_CENTER, 1.0f, 0.0f, false);

            // get height of multiline text
            int textHeight = textLayout.getHeight();

            // get position of text's top left corner  center: (bitmap.getWidth() - textWidth)/2
            float x = (bitmap.getWidth() - textWidth) / 2;
            float y = 0;
            if (i == 0)
                y = bitmap.getHeight() / 15;
            else
                y = bitmap.getHeight() - textHeight;

            // draw text to the Canvas center
            canvas.save();
            canvas.translate(x, y);
            textLayout.draw(canvas);

            // new antialiased Paint
            paint.setColor(memeSetting.getTextColor());
            paint.setStyle(Paint.Style.FILL);

            // init StaticLayout for text
            textLayout = new StaticLayout(
                    textStrings[i], paint, textWidth, Layout.Alignment.ALIGN_CENTER, 1.0f, 0.0f, false);

            // get height of multiline text
            textHeight = textLayout.getHeight();

            // draw text to the Canvas center
            textLayout.draw(canvas);
            canvas.restore();
        }
        return bitmap;
    }

    @OnTextChanged(value = R.id.memecreate__activity__edit_caption_bottom, callback = OnTextChanged.Callback.TEXT_CHANGED)
    public void onCaptionBottomChanged(CharSequence text) {
        memeSetting.setCaptionBottom(text.toString());
    }

    @OnTextChanged(value = R.id.memecreate__activity__edit_caption_top, callback = OnTextChanged.Callback.TEXT_CHANGED)
    public void onCaptionTopChanged(CharSequence text) {
        memeSetting.setCaptionTop(text.toString());
    }

    @Override
    public void onMemeSettingChanged(MemeSetting<Typeface, Bitmap> memeSetting) {
        imageEditView.setImageBitmap(null);
        if (lastBitmap != null)
            lastBitmap.recycle();
        Bitmap bmp = drawMultilineTextToBitmap(this, memeSetting);
        imageEditView.setImageBitmap(bmp);
        lastBitmap = bmp;
    }

    @Override
    public void onSheetStateChanged(BottomSheetLayout.State state) {
        if (state == BottomSheetLayout.State.HIDDEN) {
            fab.setVisibility(View.VISIBLE);
            textEditBottomCaption.setVisibility(View.VISIBLE);
            textEditTopCaption.setVisibility(View.VISIBLE);
        }
        if (state == BottomSheetLayout.State.EXPANDED || state == BottomSheetLayout.State.PEEKED) {
            textEditBottomCaption.setVisibility(View.GONE);
            textEditTopCaption.setVisibility(View.GONE);
        }
    }

    @Override
    public void onDismissed(BottomSheetLayout bottomSheetLayout) {
        fab.setVisibility(View.VISIBLE);
    }
}

我在 logcat 中收到以下错误

 E/AndroidRuntime: FATAL EXCEPTION: main
                                                                               Process: io.github.gsantner.memetastic, PID: 18271
                                                                               java.lang.RuntimeException: Unable to destroy activity {io.github.gsantner.memetastic/io.github.gsantner.memetastic.activity.MemeCreateActivity}: java.lang.NullPointerException
                                                                                   at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3497)
                                                                                   at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3515)
                                                                                   at android.app.ActivityThread.access$1400(ActivityThread.java:135)
                                                                                   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1249)
                                                                                   at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                   at android.os.Looper.loop(Looper.java:136)
                                                                                   at android.app.ActivityThread.main(ActivityThread.java:5021)
                                                                                   at java.lang.reflect.Method.invokeNative(Native Method)
                                                                                   at java.lang.reflect.Method.invoke(Method.java:515)
                                                                                   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:827)
                                                                                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:643)
                                                                                   at dalvik.system.NativeStart.main(Native Method)
                                                                                Caused by: java.lang.NullPointerException
                                                                                   at io.github.gsantner.memetastic.activity.MemeCreateActivity.onDestroy(MemeCreateActivity.java:150)
                                                                                   at android.app.Activity.performDestroy(Activity.java:5403)
                                                                                   at android.app.Instrumentation.callActivityOnDestroy(Instrumentation.java:1120)
                                                                                   at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3484)
                                                                                   at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3515) 
                                                                                   at android.app.ActivityThread.access$1400(ActivityThread.java:135) 
                                                                                   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1249) 
                                                                                   at android.os.Handler.dispatchMessage(Handler.java:102) 
                                                                                   at android.os.Looper.loop(Looper.java:136) 
                                                                                   at android.app.ActivityThread.main(ActivityThread.java:5021) 
                                                                                   at java.lang.reflect.Method.invokeNative(Native Method) 
                                                                                   at java.lang.reflect.Method.invoke(Method.java:515) 
                                                                                   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:827) 
                                                                                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:643) 
                                                                                   at dalvik.system.NativeStart.main(Native Method) 

Answer 1

问题是你调用了两次 getIntent 但实际上它应该只接收一次 intent

因此，在您的第二个 Activity 方法 onCreate 中，删除这些行

if (!(Intent.ACTION_SEND.equals(action) && type.startsWith("image/")) && (!getIntent().hasExtra(EXTRA_IMAGE_PATH) || !getIntent().hasExtra(ASSET_IMAGE))) { finish(); return; }

然后添加这些行

Intent i = getIntent();
if (!(Intent.ACTION_SEND.equals(action) && type.startsWith("image/")) && (!i.hasExtra(EXTRA_IMAGE_PATH) || !i.hasExtra(ASSET_IMAGE))) { finish(); return; }