系列文章目录

一篇文章实现Android图片拼接并保存至相册

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前言

好久没有写Android系列的文章了，最近有小伙伴问到了Android图片拼接的问题，写一篇相关的博客。

在Android应用中实现图片拼接功能并保存到相册是一个常见的需求，比如制作全景图、拼图应用或照片编辑工具。本文将介绍如何实现一个完整的图片拼接应用，包括图片选择、拼接和保存功能。

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实现功能

1. 检查并请求必要的存储权限
2. 允许用户从相册选择一张或多张图片
3. 异步加载选中的图片
4. 使用ImageStitcher类拼接图片
5. 将拼接后的图片保存到相册
6. 在整个过程中显示适当的进度指示和操作反馈

类定义和成员变量

其中包括图片选择请求码，读取权限请求码， 写入权限请求码，保存目录名称，以及相关控件。

public class MainActivity extends AppCompatActivity {private static final int PICK_IMAGE_REQUEST = 1;  // 图片选择请求码private static final int REQUEST_PERMISSION = 2;  // 读取权限请求码private static final int REQUEST_WRITE_PERMISSION = 3;  // 写入权限请求码private static final String SAVE_DIRECTORY = "ImageStitcher";  // 保存目录名称private List<Bitmap> selectedImages = new ArrayList<>();  // 存储选择的图片private ImageView resultView;  // 显示拼接结果的ImageViewprivate ProgressBar progressBar;  // 进度条private Button selectBtn, stitchBtn, saveBtn;  // 按钮控件

onCreate方法

初始化控件以及设置监听

@Override
protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);  // 设置布局文件// 初始化视图控件resultView = findViewById(R.id.jm_result_image);progressBar = findViewById(R.id.jm_progress_bar);selectBtn = findViewById(R.id.jm_select_btn);stitchBtn = findViewById(R.id.jm_stitch_btn);saveBtn = findViewById(R.id.jm_save_btn);saveBtn.setVisibility(View.GONE);  // 初始时隐藏保存按钮// 设置按钮点击监听器selectBtn.setOnClickListener(v -> checkPermissionAndOpenChooser());stitchBtn.setOnClickListener(v -> stitchImagesAsync());
}

权限检查和图片选择

不动态申请权限小心报错：has no access to content
需在AndroidManifest.xml声明READ_EXTERNAL_STORAGE权限，Android Q及以上版本必须使用MediaStore API访问公共目录文件。

private void checkPermissionAndOpenChooser() {// 检查是否有读取外部存储权限if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE)== PackageManager.PERMISSION_GRANTED) {openImageChooser();  // 有权限则直接打开图片选择器} else {// 没有权限则请求权限ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},REQUEST_PERMISSION);}
}private void openImageChooser() {// 创建选择图片的IntentIntent intent = new Intent(Intent.ACTION_GET_CONTENT);intent.setType("image/*");  // 设置类型为图片intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);  // 允许多选startActivityForResult(Intent.createChooser(intent, "选择图片"), PICK_IMAGE_REQUEST);
}// 权限请求结果回调
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {super.onRequestPermissionsResult(requestCode, permissions, grantResults);if (requestCode == REQUEST_PERMISSION && grantResults.length > 0&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {openImageChooser();  // 权限被授予后打开图片选择器}
}

处理选择的图片

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {super.onActivityResult(requestCode, resultCode, data);if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK && data != null) {handleSelectedImages(data);  // 处理选择的图片}
}private void handleSelectedImages(Intent data) {progressBar.setVisibility(View.VISIBLE);  // 显示进度条ExecutorService executor = Executors.newSingleThreadExecutor();executor.execute(() -> {try {if (data.getClipData() != null) {processMultipleImages(data.getClipData());  // 处理多张图片} else if (data.getData() != null) {processSingleImage(data.getData());  // 处理单张图片}} finally {runOnUiThread(() -> progressBar.setVisibility(View.GONE));  // 隐藏进度条}});
}private void processMultipleImages(ClipData clipData) {for (int i = 0; i < clipData.getItemCount(); i++) {loadAndAddImage(clipData.getItemAt(i).getUri());  // 加载并添加每张图片}
}private void processSingleImage(Uri uri) {loadAndAddImage(uri);  // 加载并添加单张图片
}private void loadAndAddImage(Uri uri) {try (InputStream is = getContentResolver().openInputStream(uri)) {Bitmap bitmap = BitmapFactory.decodeStream(is);  // 从URI加载图片runOnUiThread(() -> {selectedImages.add(bitmap);  // 添加到图片列表Toast.makeText(this, "成功加载图片", Toast.LENGTH_SHORT).show();});} catch (Exception e) {runOnUiThread(() ->Toast.makeText(this, "加载失败: " + e.getMessage(), Toast.LENGTH_SHORT).show());}
}

图片拼接功能

private void stitchImagesAsync() {if (selectedImages.isEmpty()) return;  // 如果没有选择图片则返回saveBtn.setVisibility(View.VISIBLE);  // 显示保存按钮progressBar.setVisibility(View.VISIBLE);  // 显示进度条ExecutorService executor = Executors.newSingleThreadExecutor();executor.execute(() -> {// 调用ImageStitcher类拼接图片Bitmap stitched = ImageStitcher.stitchImages(selectedImages.toArray(new Bitmap[0]), 0);runOnUiThread(() -> {resultView.setImageBitmap(stitched);  // 显示拼接结果progressBar.setVisibility(View.GONE);  // 隐藏进度条saveBtn.setVisibility(View.VISIBLE);  // 确保保存按钮可见// 设置保存按钮点击监听器saveBtn.setOnClickListener(v -> saveImageToGallery(stitched));});});
}

图片保存功能

private void saveImageToGallery(Bitmap bitmap) {// 检查是否有写入外部存储权限if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED) {// 没有权限则请求权限ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},REQUEST_WRITE_PERMISSION);return;}// 在新线程中执行保存操作new Thread(() -> {String fileName = "stitched_" + System.currentTimeMillis() + ".jpg";ContentValues values = new ContentValues();values.put(MediaStore.Images.Media.DISPLAY_NAME, fileName);values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");// 对于Android Q及以上版本if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {values.put(MediaStore.Images.Media.RELATIVE_PATH, Environment.DIRECTORY_PICTURES + File.separator + SAVE_DIRECTORY);values.put(MediaStore.Images.Media.IS_PENDING, 1);}try {// 插入媒体库记录Uri uri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);try (OutputStream os = getContentResolver().openOutputStream(uri)) {// 压缩并写入图片数据bitmap.compress(Bitmap.CompressFormat.JPEG, 90, os);// 对于Android Q及以上版本，更新IS_PENDING标志if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {values.put(MediaStore.Images.Media.IS_PENDING, 0);getContentResolver().update(uri, values, null, null);}// 显示保存成功提示runOnUiThread(() ->Toast.makeText(this, "图片已保存至相册", Toast.LENGTH_SHORT).show());}} catch (Exception e) {// 显示保存失败提示runOnUiThread(() ->Toast.makeText(this, "保存失败: " + e.getMessage(), Toast.LENGTH_SHORT).show());}}).start();
}

使用ImageStitcher类拼接图片

代码解释：ImageStitcher.java

这是一个用于拼接多张图片的工具类，提供了将多张图片横向或纵向拼接成一张大图的功能。下面是对代码的详细解释：

类定义和方法

public class ImageStitcher {public static Bitmap stitchImages(Bitmap[] images, int direction) {// 检查输入参数是否有效if (images == null || images.length == 0) return null;

计算拼接后图片的尺寸

        int width = images[0].getWidth();int height = images[0].getHeight();// 计算拼接后图片的总尺寸if (direction == 0) { // 横向拼接for (int i = 1; i < images.length; i++) {width += images[i].getWidth();  // 累加宽度height = Math.max(height, images[i].getHeight());  // 取最大高度}} else { // 纵向拼接for (int i = 1; i < images.length; i++) {height += images[i].getHeight();  // 累加高度width = Math.max(width, images[i].getWidth());  // 取最大宽度}}

计算逻辑

• 横向拼接：总宽度为所有图片宽度之和，高度为所有图片中的最大高度
• 纵向拼接：总高度为所有图片高度之和，宽度为所有图片中的最大宽度

创建并绘制拼接后的图片

        // 创建拼接后的BitmapBitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);Canvas canvas = new Canvas(result);// 绘制图片int currentPos = 0;for (Bitmap image : images) {if (direction == 0) { // 横向拼接canvas.drawBitmap(image, currentPos, 0, null);  // 在当前位置绘制图片currentPos += image.getWidth();  // 更新横向位置} else { // 纵向拼接canvas.drawBitmap(image, 0, currentPos, null);  // 在当前位置绘制图片currentPos += image.getHeight();  // 更新纵向位置}}return result;  // 返回拼接后的图片}
}

绘制过程

1. 创建一个新的空白Bitmap，大小为之前计算的总尺寸
2. 使用Canvas在这个Bitmap上绘制所有输入图片
3. 根据拼接方向，依次将每张图片绘制到正确的位置
4. 更新当前位置指针(currentPos)，以便下一张图片绘制在正确的位置

注意事项

• 所有输入图片应为非空且尺寸相同（代码中未做严格检查）
• 拼接方向通过简单的int值判断（0为横向，非0为纵向）
• 使用了ARGB_8888配置创建Bitmap，保证图片质量
• 这是一个基础实现，没有处理图片尺寸不一致时的缩放或裁剪

效果图

源码

MainActivity.java

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;import android.Manifest;
import android.content.ClipData;
import android.content.ContentValues;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.Toast;import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;public class MainActivity extends AppCompatActivity {private static final int PICK_IMAGE_REQUEST = 1;private static final int REQUEST_PERMISSION = 2;private List<Bitmap> selectedImages = new ArrayList<>();private ImageView resultView;private ProgressBar progressBar;private static final int REQUEST_WRITE_PERMISSION = 3;private static final String SAVE_DIRECTORY = "JmImgStitcher";private Button selectBtn,stitchBtn,saveBtn;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);resultView = findViewById(R.id.jm_result_image);progressBar = findViewById(R.id.jm_progress_bar);selectBtn = findViewById(R.id.jm_select_btn);stitchBtn = findViewById(R.id.jm_stitch_btn);// 初始化保存按钮saveBtn = findViewById(R.id.jm_save_btn);saveBtn.setVisibility(View.GONE);selectBtn.setOnClickListener(v -> checkPermissionAndOpenChooser());stitchBtn.setOnClickListener(v -> stitchImagesAsync());}private void checkPermissionAndOpenChooser() {if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE)== PackageManager.PERMISSION_GRANTED) {openImageChooser();} else {ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},REQUEST_PERMISSION);}}private void openImageChooser() {Intent intent = new Intent(Intent.ACTION_GET_CONTENT);intent.setType("image/*");intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);startActivityForResult(Intent.createChooser(intent, "选择图片"), PICK_IMAGE_REQUEST);}@Overridepublic void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {super.onRequestPermissionsResult(requestCode, permissions, grantResults);if (requestCode == REQUEST_PERMISSION && grantResults.length > 0&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {openImageChooser();}}@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {super.onActivityResult(requestCode, resultCode, data);if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK && data != null) {handleSelectedImages(data);}}private void handleSelectedImages(Intent data) {progressBar.setVisibility(View.VISIBLE);ExecutorService executor = Executors.newSingleThreadExecutor();executor.execute(() -> {try {if (data.getClipData() != null) {processMultipleImages(data.getClipData());} else if (data.getData() != null) {processSingleImage(data.getData());}} finally {runOnUiThread(() -> progressBar.setVisibility(View.GONE));}});}private void processMultipleImages(ClipData clipData) {for (int i = 0; i < clipData.getItemCount(); i++) {loadAndAddImage(clipData.getItemAt(i).getUri());}}private void processSingleImage(Uri uri) {loadAndAddImage(uri);}private void loadAndAddImage(Uri uri) {try (InputStream is = getContentResolver().openInputStream(uri)) {Bitmap bitmap = BitmapFactory.decodeStream(is);runOnUiThread(() -> {selectedImages.add(bitmap);Toast.makeText(this, "成功加载图片", Toast.LENGTH_SHORT).show();});} catch (Exception e) {runOnUiThread(() ->Toast.makeText(this, "加载失败: " + e.getMessage(), Toast.LENGTH_SHORT).show());}}// 修改stitchImagesAsync方法private void stitchImagesAsync() {if (selectedImages.isEmpty()) return;saveBtn.setVisibility(View.VISIBLE);progressBar.setVisibility(View.VISIBLE);ExecutorService executor = Executors.newSingleThreadExecutor();executor.execute(() -> {Bitmap stitched = ImageStitcher.stitchImages(selectedImages.toArray(new Bitmap[0]), 0);runOnUiThread(() -> {resultView.setImageBitmap(stitched);progressBar.setVisibility(View.GONE);//设置出现saveBtn.setVisibility(View.VISIBLE);saveBtn.setOnClickListener(v -> saveImageToGallery(stitched));});});}private void saveImageToGallery(Bitmap bitmap) {if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED) {ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},REQUEST_WRITE_PERMISSION);return;}new Thread(() -> {String fileName = "stitched_" + System.currentTimeMillis() + ".jpg";ContentValues values = new ContentValues();values.put(MediaStore.Images.Media.DISPLAY_NAME, fileName);values.put(MediaStore.Images.Media.MIME_TYPE, "image/jpeg");if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {values.put(MediaStore.Images.Media.RELATIVE_PATH, Environment.DIRECTORY_PICTURES + File.separator + SAVE_DIRECTORY);values.put(MediaStore.Images.Media.IS_PENDING, 1);}try {Uri uri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);try (OutputStream os = getContentResolver().openOutputStream(uri)) {bitmap.compress(Bitmap.CompressFormat.JPEG, 90, os);if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {values.put(MediaStore.Images.Media.IS_PENDING, 0);getContentResolver().update(uri, values, null, null);}runOnUiThread(() ->Toast.makeText(this, "图片已保存至相册", Toast.LENGTH_SHORT).show());}} catch (Exception e) {runOnUiThread(() ->Toast.makeText(this, "保存失败: " + e.getMessage(), Toast.LENGTH_SHORT).show());}}).start();}}

ImageStitcher.java

import android.graphics.Bitmap;
import android.graphics.Canvas;public class ImageStitcher {public static Bitmap stitchImages(Bitmap[] images, int direction) {if (images == null || images.length == 0) return null;int width = images[0].getWidth();int height = images[0].getHeight();// 计算拼接后图片的总尺寸if (direction == 0) { // 横向拼接for (int i = 1; i < images.length; i++) {width += images[i].getWidth();height = Math.max(height, images[i].getHeight());}} else { // 纵向拼接for (int i = 1; i < images.length; i++) {height += images[i].getHeight();width = Math.max(width, images[i].getWidth());}}// 创建拼接后的BitmapBitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);Canvas canvas = new Canvas(result);// 绘制图片int currentPos = 0;for (Bitmap image : images) {if (direction == 0) { // 横向拼接canvas.drawBitmap(image, currentPos, 0, null);currentPos += image.getWidth();} else { // 纵向拼接canvas.drawBitmap(image, 0, currentPos, null);currentPos += image.getHeight();}}return result;}
}

AndroidManifest权限申明

    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /><!-- Android 10+ 需要添加 --><uses-permission android:name="android.permission.ACCESS_MEDIA_LOCATION"android:maxSdkVersion="29" />

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"><ProgressBarandroid:id="@+id/jm_progress_bar"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_gravity="center"android:visibility="gone"/><Buttonandroid:id="@+id/jm_select_btn"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="选择要拼接的图片"/><Buttonandroid:id="@+id/jm_stitch_btn"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="开始拼接图片"/><Buttonandroid:id="@+id/jm_save_btn"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="保存图片"android:visibility="gone"/><ImageViewandroid:id="@+id/jm_result_image"android:layout_width="match_parent"android:layout_height="match_parent"android:scaleType="centerInside"/>
</LinearLayout>

总结

此文章可以作为基础，根据具体需求进行扩展和优化。欢迎留言，如有问题可以联系计蒙。