Android拼接合并图片生成长图

Android拼接合并图片生成长图

代码实现合并两张图片，以第一张图片的宽度为标准，如果被合并的第二张图片宽度和第一张不同，那么就以第一张图片的宽度为准线，对第二张图片进行缩放。

假设根目录的Pictures下已经有两张图片zhang.jpg和phil.jpg，最终把这两张图片合并成zhangphil.jpg的长图：

package zhangphil.test; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Canvas; import android.graphics.Matrix; import android.os.Bundle; import android.os.Environment; import android.support.annotation.Nullable; import android.support.v7.app.AppCompatActivity; import android.view.View; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; public class JavaActivity extends AppCompatActivity { @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.drawable_activity); findViewById(R.id.button).setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { merge(); } }); } private void merge() { new Thread(new Runnable() { @Override public void run() { File zhang = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "zhang.jpg"); File phil = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "phil.jpg"); try { Bitmap bitmap1 = BitmapFactory.decodeStream(new FileInputStream(zhang)); Bitmap bitmap2 = BitmapFactory.decodeStream(new FileInputStream(phil)); Bitmap newBmp = newBitmap(bitmap1, bitmap2); File zhangphil = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "zhangphil.jpg"); if (!zhangphil.exists()) zhangphil.createNewFile(); save(newBmp, zhangphil, Bitmap.CompressFormat.JPEG, true); } catch (Exception e) { e.printStackTrace(); } } }).start(); } public static Bitmap newBitmap(Bitmap bmp1, Bitmap bmp2) { Bitmap retBmp; int width = bmp1.getWidth(); if (bmp2.getWidth() != width) { //以第一张图片的宽度为标准，对第二张图片进行缩放。 int h2 = bmp2.getHeight() * width / bmp2.getWidth(); retBmp = Bitmap.createBitmap(width, bmp1.getHeight() + h2, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(retBmp); Bitmap newSizeBmp2 = resizeBitmap(bmp2, width, h2); canvas.drawBitmap(bmp1, 0, 0, null); canvas.drawBitmap(newSizeBmp2, 0, bmp1.getHeight(), null); } else { //两张图片宽度相等，则直接拼接。 retBmp = Bitmap.createBitmap(width, bmp1.getHeight() + bmp2.getHeight(), Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(retBmp); canvas.drawBitmap(bmp1, 0, 0, null); canvas.drawBitmap(bmp2, 0, bmp1.getHeight(), null); } return retBmp; } public static Bitmap resizeBitmap(Bitmap bitmap, int newWidth, int newHeight) { float scaleWidth = ((float) newWidth) / bitmap.getWidth(); float scaleHeight = ((float) newHeight) / bitmap.getHeight(); Matrix matrix = new Matrix(); matrix.postScale(scaleWidth, scaleHeight); Bitmap bmpScale = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true); return bmpScale; } /** * 保存图片到文件File。 * * @param src 源图片 * @param file 要保存到的文件 * @param format 格式 * @param recycle 是否回收 * @return true 成功 false 失败 */ public static boolean save(Bitmap src, File file, Bitmap.CompressFormat format, boolean recycle) { if (isEmptyBitmap(src)) return false; OutputStream os; boolean ret = false; try { os = new BufferedOutputStream(new FileOutputStream(file)); ret = src.compress(format, 100, os); if (recycle && !src.isRecycled()) src.recycle(); } catch (IOException e) { e.printStackTrace(); } return ret; } /** * Bitmap对象是否为空。 */ public static boolean isEmptyBitmap(Bitmap src) { return src == null || src.getWidth() == 0 || src.getHeight() == 0; } } 

合并后生成的长图：

添加权限：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />