uCrop使用
github地址
https://github.com/Yalantis/uCrop
然后clone或下载到本地，运行之。
效果预览
app/build.gradle
compile ‘com.yalantis:ucrop:1.5.0‘
AndroidManifest.xml
1 <activity 2 android:name="com.yalantis.ucrop.UCropActivity" 3 android:screenOrientation="portrait" 4 android:theme="@style/Theme.AppCompat.Light.NoActionBar" />
这里theme可以改成自己的
配置uCrop
1 /**
2 * 启动裁剪
3 * @param activity 上下文
4 * @param sourceFilePath 需要裁剪图片的绝对路径
5 * @param requestCode 比如：UCrop.REQUEST_CROP
6 * @param aspectRatioX 裁剪图片宽高比
7 * @param aspectRatioY 裁剪图片宽高比
8 * @return
9 */
10 public static String startUCrop(Activity activity, String sourceFilePath,
11 int requestCode, float aspectRatioX, float aspectRatioY) {
12 Uri sourceUri = Uri.fromFile(new File(sourceFilePath));
13 File outDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
14 if (!outDir.exists()) {
15 outDir.mkdirs();
16 }
17 File outFile = new File(outDir, System.currentTimeMillis() + ".jpg");
18 //裁剪后图片的绝对路径
19 String cameraScalePath = outFile.getAbsolutePath();
20 Uri destinationUri = Uri.fromFile(outFile);
21 //初始化，第一个参数：需要裁剪的图片；第二个参数：裁剪后图片
22 UCrop uCrop = UCrop.of(sourceUri, destinationUri);
23 //初始化UCrop配置
24 UCrop.Options options = new UCrop.Options();
25 //设置裁剪图片可操作的手势
26 options.setAllowedGestures(UCropActivity.SCALE, UCropActivity.ROTATE, UCropActivity.ALL);
27 //是否隐藏底部容器，默认显示
28 options.setHideBottomControls(true);
29 //设置toolbar颜色
30 options.setToolbarColor(ActivityCompat.getColor(activity, R.color.colorPrimary));
31 //设置状态栏颜色
32 options.setStatusBarColor(ActivityCompat.getColor(activity, R.color.colorPrimary));
33 //是否能调整裁剪框
34 options.setFreeStyleCropEnabled(true);
35 //UCrop配置
36 uCrop.withOptions(options);
37 //设置裁剪图片的宽高比，比如16：9
38 uCrop.withAspectRatio(aspectRatioX, aspectRatioY);
39 //uCrop.useSourceImageAspectRatio();
40 //跳转裁剪页面
41 uCrop.start(activity, requestCode);
42 return cameraScalePath;
43 }
其他配置
1 //设置Toolbar标题 2 void setToolbarTitle(@Nullable String text) 3 //设置裁剪的图片格式 4 void setCompressionFormat(@NonNull Bitmap.CompressFormat format) 5 //设置裁剪的图片质量，取值0-100 6 void setCompressionQuality(@IntRange(from = 0) int compressQuality) 7 //设置最多缩放的比例尺 8 void setMaxScaleMultiplier(@FloatRange(from = 1.0, fromInclusive = false) float maxScaleMultiplier) 9 //动画时间 10 void setImageToCropBoundsAnimDuration(@IntRange(from = 100) int durationMillis) 11 //设置图片压缩最大值 12 void setMaxBitmapSize(@IntRange(from = 100) int maxBitmapSize) 13 //是否显示椭圆裁剪框阴影 14 void setOvalDimmedLayer(boolean isOval) 15 //设置椭圆裁剪框阴影颜色 16 void setDimmedLayerColor(@ColorInt int color) 17 //是否显示裁剪框 18 void setShowCropFrame(boolean show) 19 //设置裁剪框边的宽度 20 void setCropFrameStrokeWidth(@IntRange(from = 0) int width) 21 //是否显示裁剪框网格 22 void setShowCropGrid(boolean show) 23 //设置裁剪框网格颜色 24 void setCropGridColor(@ColorInt int color) 25 //设置裁剪框网格宽 26 void setCropGridStrokeWidth(@IntRange(from = 0) int width)
onActivityResult
经过裁剪，返回结果，这里我一般只需要裁剪后的图片绝对路径（调用上面startUCrop，即返回图片路径），然后调接口上传服务器。
1 @Override
2 public void onActivityResult(int requestCode, int resultCode, Intent data) {
3 if (resultCode == RESULT_OK && requestCode == UCrop.REQUEST_CROP) {
4 final Uri resultUri = UCrop.getOutput(data);
5 } else if (resultCode == UCrop.RESULT_ERROR) {
6 final Throwable cropError = UCrop.getError(data);
7 }
8 }
uCrop源码浅析
uCrop源码能学习的东西有很多，比如左右滑的标尺，不过我们这里源码浅析只关注裁剪部分。
类关系
首先有个大概了解：
GestureCropImageView：负责监听各种手势
CropImageView：主要完成图片裁剪工作，和判断裁剪图片是否充满裁剪框
TransformImageView：负责图片旋转、缩放、位移操作
入口
由上面的效果图可知，点击右上角，调用裁剪操作，代码如下：
1 @Override
2 public boolean onOptionsItemSelected(MenuItem item) {
3 if (item.getItemId() == R.id.menu_crop) {
4 cropAndSaveImage();
5 }
6 return super.onOptionsItemSelected(item);
7 }
8 //裁剪和保存图片
9 protected void cropAndSaveImage() {
10 ……
11 mGestureCropImageView.cropAndSaveImage(mCompressFormat, mCompressQuality, new BitmapCropCallback() {
12 @Override
13 public void onBitmapCropped(@NonNull Uri resultUri) {
14 setResultUri(resultUri, mGestureCropImageView.getTargetAspectRatio());
15 finish();
16 }
17 @Override
18 public void onCropFailure(@NonNull Throwable t) {
19 setResultError(t);
20 finish();
21 }
22 });
23 }
这里调用了GestureCropImageView&cropAndSaveImage方法，如下：
1 /**
2 * @param compressFormat 图片压缩格式
3 * @param compressQuality 图片压缩质量
4 * @param cropCallback 图片压缩回调
5 */
6 public void cropAndSaveImage(@NonNull Bitmap.CompressFormat compressFormat, int compressQuality,@Nullable BitmapCropCallback cropCallback) {
7 //取消所有动画
8 cancelAllAnimations();
9 //判断裁剪图片是否充满裁剪框
10 setImageToWrapCropBounds(false);
11 //进行裁剪
12 new BitmapCropTask(getViewBitmap(), mCropRect, RectUtils.trapToRect(mCurrentImageCorners),
13 getCurrentScale(), getCurrentAngle(),
14 mMaxResultImageSizeX, mMaxResultImageSizeY,
15 compressFormat, compressQuality,
16 getImageInputPath(), getImageOutputPath(),
17 cropCallback).execute();
18 }
裁剪之前
setImageToWrapCropBounds
裁剪之前，先判断裁剪图片是否充满裁剪框，如果没有，进行移动和缩放让其充满。
1 public void setImageToWrapCropBounds(boolean animate) {
2 //mBitmapLaidOut图片加载OK，isImageWrapCropBounds()检查图片是否充满裁剪框
3 if (mBitmapLaidOut && !isImageWrapCropBounds()) {
4 //当前图片中心X点
5 float currentX = mCurrentImageCenter[0];
6 //当前图片中心Y点
7 float currentY = mCurrentImageCenter[1];
8 //当前图片缩放值
9 float currentScale = getCurrentScale();
10 //差量
11 float deltaX = mCropRect.centerX() - currentX;
12 float deltaY = mCropRect.centerY() - currentY;
13 float deltaScale = 0;
14 //临时矩阵重置
15 mTempMatrix.reset();
16 //临时矩阵移动
17 mTempMatrix.setTranslate(deltaX, deltaY);
18 //复制到新的数组
19 final float[] tempCurrentImageCorners = Arrays.copyOf(mCurrentImageCorners, mCurrentImageCorners.length);
20 //将此矩阵应用于二维点的数组，并编写转换后的指向数组的点
21 mTempMatrix.mapPoints(tempCurrentImageCorners);
22 //再检查图片是否充满裁剪框
23 boolean willImageWrapCropBoundsAfterTranslate = isImageWrapCropBounds(tempCurrentImageCorners);
24 if (willImageWrapCropBoundsAfterTranslate) {
25 //图片缩进的数组
26 final float[] imageIndents = calculateImageIndents();
27 deltaX = -(imageIndents[0] + imageIndents[2]);
28 deltaY = -(imageIndents[1] + imageIndents[3]);
29 } else {
30 RectF tempCropRect = new RectF(mCropRect);
31 mTempMatrix.reset();
32 mTempMatrix.setRotate(getCurrentAngle());
33 mTempMatrix.mapRect(tempCropRect);
34 //获取裁剪图片的边
35 final float[] currentImageSides = RectUtils.getRectSidesFromCorners(mCurrentImageCorners);
36 deltaScale = Math.max(tempCropRect.width() / currentImageSides[0],
37 tempCropRect.height() / currentImageSides[1]);
38 deltaScale = deltaScale * currentScale - currentScale;
39 }
40 if (animate) {
41 //移动或缩放图片（有动画效果）
42 post(mWrapCropBoundsRunnable = new WrapCropBoundsRunnable(
43 CropImageView.this, mImageToWrapCropBoundsAnimDuration, currentX, currentY, deltaX, deltaY,
44 currentScale, deltaScale, willImageWrapCropBoundsAfterTranslate));
45 } else {
46 //移动图片
47 postTranslate(deltaX, deltaY);
48 if (!willImageWrapCropBoundsAfterTranslate) {
49 //缩放图片
50 zoomInImage(currentScale + deltaScale, mCropRect.centerX(), mCropRect.centerY());
51 }
52 }
53 }
54 }
进行裁剪
裁剪放到了异步，即BitmapCropTask继承AsyncTask，先设置原始图片resizeScale值，然后通过ExifInterface保存新的图片，即裁剪后的图片
1 public class BitmapCropTask extends AsyncTask<Void, Void, Throwable> {
2
3 ……
4 /**
5 * @param viewBitmap 裁剪图片bitmap
6 * @param cropRect 裁剪矩形
7 * @param currentImageRect 当前图片矩形
8 * @param currentScale 当前图片缩放值
9 * @param currentAngle 当前图片角度
10 * @param maxResultImageSizeX 图片裁剪后最大宽值
11 * @param maxResultImageSizeY 图片裁剪后最大高值
12 * @param compressFormat 图片裁剪的格式
13 * @param compressQuality 图片裁剪的质量
14 * @param imageInputPath 裁剪图片路径
15 * @param imageOutputPath 图片裁剪后路径
16 * @param cropCallback 裁剪回调
17 */
18 public BitmapCropTask(@Nullable Bitmap viewBitmap,
19 @NonNull RectF cropRect, @NonNull RectF currentImageRect,
20 float currentScale, float currentAngle,
21 int maxResultImageSizeX, int maxResultImageSizeY,
22 @NonNull Bitmap.CompressFormat compressFormat, int compressQuality,
23 @NonNull String imageInputPath, @NonNull String imageOutputPath,
24 @Nullable BitmapCropCallback cropCallback) {
25 ……
26 }
27 @Override
28 @Nullable
29 protected Throwable doInBackground(Void... params) {
30 if (mViewBitmap == null || mViewBitmap.isRecycled()) {
31 return new NullPointerException("ViewBitmap is null or already recycled");
32 }
33 if (mCurrentImageRect.isEmpty()) {
34 return new NullPointerException("CurrentImageRect is empty");
35 }
36 //设置resizeScale值
37 float resizeScale = resize();
38 try {
39 //裁剪
40 crop(resizeScale);
41 //回收
42 mViewBitmap.recycle();
43 mViewBitmap = null;
44 } catch (Throwable throwable) {
45 return throwable;
46 }
47 return null;
48 }
49 private float resize() {
50 //初始Options
51 final BitmapFactory.Options options = new BitmapFactory.Options();
52 //查询该位图，而无需分配存储器，可获取outHeight(图片原始高度)和 outWidth(图片的原始宽度)
53 options.inJustDecodeBounds = true;
54 //裁剪图片解码
55 BitmapFactory.decodeFile(mImageInputPath, options);
56 //原始图片和裁剪后图片比值
57 float scaleX = options.outWidth / mViewBitmap.getWidth();
58 float scaleY = options.outHeight / mViewBitmap.getHeight();
59 float resizeScale = Math.min(scaleX, scaleY);
60 mCurrentScale /= resizeScale;
61 //初始化值为1
62 resizeScale = 1;
63 if (mMaxResultImageSizeX > 0 && mMaxResultImageSizeY > 0) {
64 float cropWidth = mCropRect.width() / mCurrentScale;
65 float cropHeight = mCropRect.height() / mCurrentScale;
66 if (cropWidth > mMaxResultImageSizeX || cropHeight > mMaxResultImageSizeY) {
67 scaleX = mMaxResultImageSizeX / cropWidth;
68 scaleY = mMaxResultImageSizeY / cropHeight;
69 //设置resizeScale，如果是2就是高度和宽度都是原始的一半
70 resizeScale = Math.min(scaleX, scaleY);
71 mCurrentScale /= resizeScale;
72 }
73 }
74 return resizeScale;
75 }
76 private boolean crop(float resizeScale) throws IOException {
77 //ExifInterface这个接口提供了图片文件的旋转，gps，时间等信息，从原始图片读出Exif标签
78 ExifInterface originalExif = new ExifInterface(mImageInputPath);
79 int top = Math.round((mCropRect.top - mCurrentImageRect.top) / mCurrentScale);
80 int left = Math.round((mCropRect.left - mCurrentImageRect.left) / mCurrentScale);
81 int width = Math.round(mCropRect.width() / mCurrentScale);
82 int height = Math.round(mCropRect.height() / mCurrentScale);
83 //复制图片
84 boolean cropped = cropCImg(mImageInputPath, mImageOutputPath,
85 left, top, width, height, mCurrentAngle, resizeScale,
86 mCompressFormat.ordinal(), mCompressQuality);
87 if (cropped) {
88 //拿到裁剪后图片
89 copyExif(originalExif, width, height);
90 }
91 return cropped;
92 }
93 @SuppressWarnings("JniMissingFunction")
94 native public boolean cropCImg(String inputPath, String outputPath,
95 int left, int top, int width, int height, float angle, float resizeScale,
96 int format, int quality) throws IOException, OutOfMemoryError;
97 /**
98 * @param originalExif 原始图片Exif
99 * @param width 裁剪后图片宽
100 * @param height 裁剪后图片高
101 * @throws IOException 是否异常
102 */
103 public void copyExif(ExifInterface originalExif, int width, int height) throws IOException {
104 //Exif标签数组
105 String[] attributes = new String[]{
106 ExifInterface.TAG_APERTURE,
107 ……
108 };
109 //指定裁剪后图片路径，初始化新的ExifInterface
110 ExifInterface newExif = new ExifInterface(mImageOutputPath);
111 String value;
112 for (String attribute : attributes) {
113 value = originalExif.getAttribute(attribute);
114 if (!TextUtils.isEmpty(value)) {
115 //设置Exif标签
116 newExif.setAttribute(attribute, value);
117 }
118 }
119 newExif.setAttribute(ExifInterface.TAG_IMAGE_WIDTH, String.valueOf(width));
120 newExif.setAttribute(ExifInterface.TAG_IMAGE_LENGTH, String.valueOf(height));
121 newExif.setAttribute(ExifInterface.TAG_ORIENTATION, "0");
122 //保存
123 newExif.saveAttributes();
124 }
125 @Override
126 protected void onPostExecute(@Nullable Throwable t) {
127 if (mCropCallback != null) {
128 if (t == null) {
129 //接口回调，over
130 mCropCallback.onBitmapCropped(Uri.fromFile(new File(mImageOutputPath)));
131 } else {
132 mCropCallback.onCropFailure(t);
133 }
134 }
135 }
136 }
总结
uCrop功能强大，对于我来说，有很多东西值得学习，难点如Rect包含问题（其实这块还不是很理解），新知识如ExifInterface操作图片，BitmapFactory显示图片的知识点温故等，还有自定义左右滑的标尺，都是不错的学习源码。抛砖引玉至此，over。
原文地址：https://www.cnblogs.com/ganchuanpu/p/8490518.html
时间： 2024-10-08 06:10:15