系列文章目錄

一篇文章實現Android圖片拼接并保存至相冊

---

---

前言

好久沒有寫Android系列的文章了，最近有小伙伴問到了Android圖片拼接的問題，寫一篇相關的博客。

在Android應用中實現圖片拼接功能并保存到相冊是一個常見的需求，比如制作全景圖、拼圖應用或照片編輯工具。本文將介紹如何實現一個完整的圖片拼接應用，包括圖片選擇、拼接和保存功能。

---

實現功能

1. 檢查并請求必要的存儲權限
2. 允許用戶從相冊選擇一張或多張圖片
3. 異步加載選中的圖片
4. 使用ImageStitcher類拼接圖片
5. 將拼接后的圖片保存到相冊
6. 在整個過程中顯示適當的進度指示和操作反饋

類定義和成員變量

其中包括圖片選擇請求碼，讀取權限請求碼， 寫入權限請求碼，保存目錄名稱，以及相關控件。

public class MainActivity extends AppCompatActivity {private static final int PICK_IMAGE_REQUEST = 1;  // 圖片選擇請求碼private static final int REQUEST_PERMISSION = 2;  // 讀取權限請求碼private static final int REQUEST_WRITE_PERMISSION = 3;  // 寫入權限請求碼private static final String SAVE_DIRECTORY = "ImageStitcher";  // 保存目錄名稱private List<Bitmap> selectedImages = new ArrayList<>();  // 存儲選擇的圖片private ImageView resultView;  // 顯示拼接結果的ImageViewprivate ProgressBar progressBar;  // 進度條private Button selectBtn, stitchBtn, saveBtn;  // 按鈕控件

onCreate方法

初始化控件以及設置監聽

@Override
protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);  // 設置布局文件// 初始化視圖控件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);  // 初始時隱藏保存按鈕// 設置按鈕點擊監聽器selectBtn.setOnClickListener(v -> checkPermissionAndOpenChooser());stitchBtn.setOnClickListener(v -> stitchImagesAsync());
}

權限檢查和圖片選擇

不動態申請權限小心報錯：has no access to content
需在AndroidManifest.xml聲明READ_EXTERNAL_STORAGE權限，Android Q及以上版本必須使用MediaStore API訪問公共目錄文件。

private void checkPermissionAndOpenChooser() {// 檢查是否有讀取外部存儲權限if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE)== PackageManager.PERMISSION_GRANTED) {openImageChooser();  // 有權限則直接打開圖片選擇器} else {// 沒有權限則請求權限ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},REQUEST_PERMISSION);}
}private void openImageChooser() {// 創建選擇圖片的IntentIntent intent = new Intent(Intent.ACTION_GET_CONTENT);intent.setType("image/*");  // 設置類型為圖片intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);  // 允許多選startActivityForResult(Intent.createChooser(intent, "選擇圖片"), PICK_IMAGE_REQUEST);
}// 權限請求結果回調
@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();  // 權限被授予后打開圖片選擇器}
}

處理選擇的圖片

@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);  // 處理選擇的圖片}
}private void handleSelectedImages(Intent data) {progressBar.setVisibility(View.VISIBLE);  // 顯示進度條ExecutorService executor = Executors.newSingleThreadExecutor();executor.execute(() -> {try {if (data.getClipData() != null) {processMultipleImages(data.getClipData());  // 處理多張圖片} else if (data.getData() != null) {processSingleImage(data.getData());  // 處理單張圖片}} finally {runOnUiThread(() -> progressBar.setVisibility(View.GONE));  // 隱藏進度條}});
}private void processMultipleImages(ClipData clipData) {for (int i = 0; i < clipData.getItemCount(); i++) {loadAndAddImage(clipData.getItemAt(i).getUri());  // 加載并添加每張圖片}
}private void processSingleImage(Uri uri) {loadAndAddImage(uri);  // 加載并添加單張圖片
}private void loadAndAddImage(Uri uri) {try (InputStream is = getContentResolver().openInputStream(uri)) {Bitmap bitmap = BitmapFactory.decodeStream(is);  // 從URI加載圖片runOnUiThread(() -> {selectedImages.add(bitmap);  // 添加到圖片列表Toast.makeText(this, "成功加載圖片", Toast.LENGTH_SHORT).show();});} catch (Exception e) {runOnUiThread(() ->Toast.makeText(this, "加載失敗: " + e.getMessage(), Toast.LENGTH_SHORT).show());}
}

圖片拼接功能

private void stitchImagesAsync() {if (selectedImages.isEmpty()) return;  // 如果沒有選擇圖片則返回saveBtn.setVisibility(View.VISIBLE);  // 顯示保存按鈕progressBar.setVisibility(View.VISIBLE);  // 顯示進度條ExecutorService executor = Executors.newSingleThreadExecutor();executor.execute(() -> {// 調用ImageStitcher類拼接圖片Bitmap stitched = ImageStitcher.stitchImages(selectedImages.toArray(new Bitmap[0]), 0);runOnUiThread(() -> {resultView.setImageBitmap(stitched);  // 顯示拼接結果progressBar.setVisibility(View.GONE);  // 隱藏進度條saveBtn.setVisibility(View.VISIBLE);  // 確保保存按鈕可見// 設置保存按鈕點擊監聽器saveBtn.setOnClickListener(v -> saveImageToGallery(stitched));});});
}

圖片保存功能

private void saveImageToGallery(Bitmap bitmap) {// 檢查是否有寫入外部存儲權限if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED) {// 沒有權限則請求權限ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},REQUEST_WRITE_PERMISSION);return;}// 在新線程中執行保存操作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");// 對于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 {// 插入媒體庫記錄Uri uri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);try (OutputStream os = getContentResolver().openOutputStream(uri)) {// 壓縮并寫入圖片數據bitmap.compress(Bitmap.CompressFormat.JPEG, 90, os);// 對于Android Q及以上版本，更新IS_PENDING標志if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {values.put(MediaStore.Images.Media.IS_PENDING, 0);getContentResolver().update(uri, values, null, null);}// 顯示保存成功提示runOnUiThread(() ->Toast.makeText(this, "圖片已保存至相冊", Toast.LENGTH_SHORT).show());}} catch (Exception e) {// 顯示保存失敗提示runOnUiThread(() ->Toast.makeText(this, "保存失敗: " + e.getMessage(), Toast.LENGTH_SHORT).show());}}).start();
}

使用ImageStitcher類拼接圖片

代碼解釋：ImageStitcher.java

這是一個用于拼接多張圖片的工具類，提供了將多張圖片橫向或縱向拼接成一張大圖的功能。下面是對代碼的詳細解釋：

類定義和方法

public class ImageStitcher {public static Bitmap stitchImages(Bitmap[] images, int direction) {// 檢查輸入參數是否有效if (images == null || images.length == 0) return null;

計算拼接后圖片的尺寸

        int width = images[0].getWidth();int height = images[0].getHeight();// 計算拼接后圖片的總尺寸if (direction == 0) { // 橫向拼接for (int i = 1; i < images.length; i++) {width += images[i].getWidth();  // 累加寬度height = Math.max(height, images[i].getHeight());  // 取最大高度}} else { // 縱向拼接for (int i = 1; i < images.length; i++) {height += images[i].getHeight();  // 累加高度width = Math.max(width, images[i].getWidth());  // 取最大寬度}}

計算邏輯

• 橫向拼接：總寬度為所有圖片寬度之和，高度為所有圖片中的最大高度
• 縱向拼接：總高度為所有圖片高度之和，寬度為所有圖片中的最大寬度

創建并繪制拼接后的圖片

        // 創建拼接后的BitmapBitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);Canvas canvas = new Canvas(result);// 繪制圖片int currentPos = 0;for (Bitmap image : images) {if (direction == 0) { // 橫向拼接canvas.drawBitmap(image, currentPos, 0, null);  // 在當前位置繪制圖片currentPos += image.getWidth();  // 更新橫向位置} else { // 縱向拼接canvas.drawBitmap(image, 0, currentPos, null);  // 在當前位置繪制圖片currentPos += image.getHeight();  // 更新縱向位置}}return result;  // 返回拼接后的圖片}
}

繪制過程

1. 創建一個新的空白Bitmap，大小為之前計算的總尺寸
2. 使用Canvas在這個Bitmap上繪制所有輸入圖片
3. 根據拼接方向，依次將每張圖片繪制到正確的位置
4. 更新當前位置指針(currentPos)，以便下一張圖片繪制在正確的位置

注意事項

• 所有輸入圖片應為非空且尺寸相同（代碼中未做嚴格檢查）
• 拼接方向通過簡單的int值判斷（0為橫向，非0為縱向）
• 使用了ARGB_8888配置創建Bitmap，保證圖片質量
• 這是一個基礎實現，沒有處理圖片尺寸不一致時的縮放或裁剪

效果圖

源碼

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);// 初始化保存按鈕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, "選擇圖片"), 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, "成功加載圖片", Toast.LENGTH_SHORT).show();});} catch (Exception e) {runOnUiThread(() ->Toast.makeText(this, "加載失敗: " + 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);//設置出現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, "圖片已保存至相冊", Toast.LENGTH_SHORT).show());}} catch (Exception e) {runOnUiThread(() ->Toast.makeText(this, "保存失敗: " + 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();// 計算拼接后圖片的總尺寸if (direction == 0) { // 橫向拼接for (int i = 1; i < images.length; i++) {width += images[i].getWidth();height = Math.max(height, images[i].getHeight());}} else { // 縱向拼接for (int i = 1; i < images.length; i++) {height += images[i].getHeight();width = Math.max(width, images[i].getWidth());}}// 創建拼接后的BitmapBitmap result = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);Canvas canvas = new Canvas(result);// 繪制圖片int currentPos = 0;for (Bitmap image : images) {if (direction == 0) { // 橫向拼接canvas.drawBitmap(image, currentPos, 0, null);currentPos += image.getWidth();} else { // 縱向拼接canvas.drawBitmap(image, 0, currentPos, null);currentPos += image.getHeight();}}return result;}
}

AndroidManifest權限申明

    <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="選擇要拼接的圖片"/><Buttonandroid:id="@+id/jm_stitch_btn"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="開始拼接圖片"/><Buttonandroid:id="@+id/jm_save_btn"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="保存圖片"android:visibility="gone"/><ImageViewandroid:id="@+id/jm_result_image"android:layout_width="match_parent"android:layout_height="match_parent"android:scaleType="centerInside"/>
</LinearLayout>

總結

此文章可以作為基礎，根據具體需求進行擴展和優化。歡迎留言，如有問題可以聯系計蒙。