Java 在ImageView上显示裁剪的图像

概述：我有一个简单的布局，有一个按钮，按下该按钮时。。打开gallery告诉我选择要裁剪的图片，一旦选择了图片，它就会进入裁剪图像屏幕。一旦图像裁剪完成，我点击“保存/完成”，它就会在我的ImageView上显示新裁剪的图像

package com.example.pau.crop_test;

import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.File;

public class ImageSelecter extends Activity {

    private final int GALLERY_ACTIVITY_CODE = 200;
    private final int RESULT_CROP = 400;
    private ImageView imageView2;

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

        ImageView imageView2 = (ImageView) findViewById(R.id.imageView2);
        Button profile_button = (Button) findViewById(R.id.button);
        profile_button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                //Start Activity To Select Image From Gallery   
                Intent gallery_Intent = new Intent(getApplicationContext(), GalleryUtil.class);
                startActivityForResult(gallery_Intent, GALLERY_ACTIVITY_CODE);

            }
        });

    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == GALLERY_ACTIVITY_CODE) {
            if (resultCode == Activity.RESULT_OK) {
                String picturePath = data.getStringExtra("picturePath");
                //perform Crop on the Image Selected from Gallery
                performCrop(picturePath);
            }
        }

        if (requestCode == RESULT_CROP) {
            if (resultCode == Activity.RESULT_OK) {
                if (data != null) {
                    Bundle extras = data.getExtras();
                    if (extras != null) {
                        Bitmap selectedBitmap = extras.getParcelable("data");
                        // Set The Bitmap Data To ImageView

                        ImageView image =(ImageView) findViewById(R.id.imageView2);
                        image.setImageBitmap(selectedBitmap);
                       // imageView2.setScaleType(ImageView.ScaleType.FIT_XY);
                        }
                    }
                }
            }
        }


    private void performCrop(String picUri) {
        try {
            //Start Crop Activity

            Intent cropIntent = new Intent("com.android.camera.action.CROP");
            // indicate image type and Uri
            File f = new File(picUri);
            Uri contentUri = Uri.fromFile(f);

            cropIntent.setDataAndType(contentUri, "image/*");
            // set crop properties
            cropIntent.putExtra("crop", "true");
            // indicate aspect of desired crop
            cropIntent.putExtra("aspectX", 1);
            cropIntent.putExtra("aspectY", 1);
            // indicate output X and Y
            cropIntent.putExtra("outputX", 280);
            cropIntent.putExtra("outputY", 280);

            // retrieve data on return
            cropIntent.putExtra("return-data", true);
            // start the activity - we handle returning in onActivityResult
            startActivityForResult(cropIntent, RESULT_CROP);
        }
        // respond to users whose devices do not support the crop action
        catch (ActivityNotFoundException anfe) {
            // display an error message
            String errorMessage = "your device doesn't support the crop action!";
            Toast toast = Toast.makeText(this, errorMessage, Toast.LENGTH_SHORT);
            toast.show();
        }
    }

问题：我似乎无法在ImageView上显示新裁剪的图像；当我在裁剪完图像后点击“保存”时，它会返回到我的主布局，指示它已保存，但它从不在视图上显示图像

按下按钮后，此活动开始，进入第二个活动。获取第二个活动的图片后，它将裁剪图像并将其显示在ImageView上

package com.example.pau.crop_test;

import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.File;

public class ImageSelecter extends Activity {

    private final int GALLERY_ACTIVITY_CODE = 200;
    private final int RESULT_CROP = 400;
    private ImageView imageView2;

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

        ImageView imageView2 = (ImageView) findViewById(R.id.imageView2);
        Button profile_button = (Button) findViewById(R.id.button);
        profile_button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                //Start Activity To Select Image From Gallery   
                Intent gallery_Intent = new Intent(getApplicationContext(), GalleryUtil.class);
                startActivityForResult(gallery_Intent, GALLERY_ACTIVITY_CODE);

            }
        });

    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == GALLERY_ACTIVITY_CODE) {
            if (resultCode == Activity.RESULT_OK) {
                String picturePath = data.getStringExtra("picturePath");
                //perform Crop on the Image Selected from Gallery
                performCrop(picturePath);
            }
        }

        if (requestCode == RESULT_CROP) {
            if (resultCode == Activity.RESULT_OK) {
                if (data != null) {
                    Bundle extras = data.getExtras();
                    if (extras != null) {
                        Bitmap selectedBitmap = extras.getParcelable("data");
                        // Set The Bitmap Data To ImageView

                        ImageView image =(ImageView) findViewById(R.id.imageView2);
                        image.setImageBitmap(selectedBitmap);
                       // imageView2.setScaleType(ImageView.ScaleType.FIT_XY);
                        }
                    }
                }
            }
        }


    private void performCrop(String picUri) {
        try {
            //Start Crop Activity

            Intent cropIntent = new Intent("com.android.camera.action.CROP");
            // indicate image type and Uri
            File f = new File(picUri);
            Uri contentUri = Uri.fromFile(f);

            cropIntent.setDataAndType(contentUri, "image/*");
            // set crop properties
            cropIntent.putExtra("crop", "true");
            // indicate aspect of desired crop
            cropIntent.putExtra("aspectX", 1);
            cropIntent.putExtra("aspectY", 1);
            // indicate output X and Y
            cropIntent.putExtra("outputX", 280);
            cropIntent.putExtra("outputY", 280);

            // retrieve data on return
            cropIntent.putExtra("return-data", true);
            // start the activity - we handle returning in onActivityResult
            startActivityForResult(cropIntent, RESULT_CROP);
        }
        // respond to users whose devices do not support the crop action
        catch (ActivityNotFoundException anfe) {
            // display an error message
            String errorMessage = "your device doesn't support the crop action!";
            Toast toast = Toast.makeText(this, errorMessage, Toast.LENGTH_SHORT);
            toast.show();
        }
    }

下面是第二个活动，允许我们进入图库选择一张图片，然后将其返回到第一个活动进行裁剪：

package com.example.pau.crop_test;

import java.io.File;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;

public class GalleryUtil extends Activity{
    private final static int RESULT_SELECT_IMAGE = 100;
    public static final int MEDIA_TYPE_IMAGE = 1;
    private static final String TAG = "GalleryUtil";

    String mCurrentPhotoPath;
    File photoFile = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


        try{
            //Pick Image From Gallery
            Intent i = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            startActivityForResult(i, RESULT_SELECT_IMAGE);
        }catch(Exception e){
            e.printStackTrace();
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        switch(requestCode){
            case RESULT_SELECT_IMAGE:

                if (resultCode == Activity.RESULT_OK && data != null && data.getData() != null) {
                    try{
                        Uri selectedImage = data.getData();
                        String[] filePathColumn = {MediaStore.Images.Media.DATA };
                        Cursor cursor = getContentResolver().query(selectedImage,
                                filePathColumn, null, null, null);
                        cursor.moveToFirst();
                        int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
                        String picturePath = cursor.getString(columnIndex);
                        cursor.close();

                        //return Image Path to the Main Activity
                        Intent returnFromGalleryIntent = new Intent();
                        returnFromGalleryIntent.putExtra("picturePath",picturePath);
                        setResult(RESULT_OK,returnFromGalleryIntent);
                        finish();
                    }catch(Exception e){
                        e.printStackTrace();
                        Intent returnFromGalleryIntent = new Intent();
                        setResult(RESULT_CANCELED, returnFromGalleryIntent);
                        finish();
                    }
                }else{
                    Log.i(TAG,"RESULT_CANCELED");
                    Intent returnFromGalleryIntent = new Intent();
                    setResult(RESULT_CANCELED, returnFromGalleryIntent);
                    finish();
                }
                break;
        }
    }
}

下面是我的布局，其中显示按钮和图像视图：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#FFFFFF"
    >

    <ImageView
        android:layout_width="200dp"
        android:layout_height="fill_parent"
        android:id="@+id/imageView2"

        android:layout_marginTop="41dp"
        android:contentDescription="@string/abc_activity_chooser_view_see_all" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/crop"
        android:id="@+id/button"
        android:layout_centerVertical="true"
        android:layout_toRightOf="@+id/imageView2"
        android:layout_toEndOf="@+id/imageView2" />


</RelativeLayout>

在

requestCode==RESULT\u CROP

块中进行一些调试，以确保部分正在运行。如果

ImageView

没有得到更新，并且由于您进行更新的唯一地方是成功的裁剪，那么它将表明活动没有像您预期的那样返回

，包括与问题无关的部分（所谓的绒毛或闲聊），这会增加您的文本输入错误的几率（环境！）别提了。