Merge pull request OpenFlutter#475 from 9527001/feat-compress_ios

分享小程序，data数据压缩成功，但是image转data 导致图片大小变大
sunpulun · Apr 14, 2022 · 518f31b · 518f31b
2 parents dc5be0e + 4457611
commit 518f31b
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Showing 3 changed files with 70 additions and 10 deletions.
diff --git a/ios/Classes/FluwxShareHandler.m b/ios/Classes/FluwxShareHandler.m
@@ -235,16 +235,15 @@ - (void)shareMiniProgram:(FlutterMethodCall *)call result:(FlutterResult)result
         NSDictionary *hdImagePath = call.arguments[@"hdImagePath"];
         if (hdImagePath != (id) [NSNull null]) {
             NSData *imageData = [self getNsDataFromWeChatFile:hdImagePath];
-            NSString *suffix = hdImagePath[@"suffix"];
-            BOOL isPNG = [self isPNG:suffix];
             BOOL compress = call.arguments[fluwxKeyCompressThumbnail];
 
-            UIImage *uiImage = [self getThumbnailFromNSData:imageData size:120 * 1024 isPNG:isPNG compress:compress];
-            if (isPNG) {
-                hdImageData = UIImagePNGRepresentation(uiImage);
-            } else {
-                hdImageData = UIImageJPEGRepresentation(uiImage, 1);
-            }
+            hdImageData = [self getThumbnailDataFromNSData:imageData size:120 * 1024 compress:compress];
+//            UIImage *uiImage = [self getThumbnailFromNSData:imageData size:120 * 1024 isPNG:isPNG compress:compress];
+//            if (isPNG) {
+//                hdImageData = UIImagePNGRepresentation(uiImage);
+//            } else {
+//                hdImageData = UIImageJPEGRepresentation(uiImage, 1);
+//            }
         }
 
         dispatch_async(dispatch_get_main_queue(), ^{
@@ -332,6 +331,14 @@ - (UIImage *)getThumbnailFromNSData:(NSData *)data size:(NSUInteger)size isPNG:(
         return uiImage;
 }
 
+- (NSData *)getThumbnailDataFromNSData:(NSData *)data size:(NSUInteger)size compress:(BOOL)compress {
+    if(compress) {
+        return [ThumbnailHelper compressImageData:data toByte:size];
+    } else{
+        return data;
+    }
+}
+
 - (NSString *)readFileFromAssets:(NSString *)imagePath {
     NSArray *array = [self formatAssets:imagePath];
     NSString *key;

diff --git a/ios/Classes/ThumbnailHelper.h b/ios/Classes/ThumbnailHelper.h
@@ -7,4 +7,10 @@
 
 @interface ThumbnailHelper : NSObject
 + (UIImage *)compressImage:(UIImage *)image toByte:(NSUInteger)maxLength isPNG:(BOOL)isPNG;
-@end
+
+
+/// NSData 压缩后转NSData
+/// @param imageData 来源data
+/// @param maxLength 压缩目标值，压缩结果在maxLength的0.9~1之间
++ (NSData *)compressImageData:(NSData *)imageData toByte:(NSUInteger)maxLength;
+@end
diff --git a/ios/Classes/ThumbnailHelper.m b/ios/Classes/ThumbnailHelper.m
@@ -7,6 +7,53 @@
 
 @implementation ThumbnailHelper
 
++ (NSData *)compressImageData:(NSData *)imageData toByte:(NSUInteger)maxLength {
+    // Compress by quality
+    CGFloat compression = 1;
+    NSData *data = imageData;
+    NSLog(@"压缩前 %lu  %lu  ",(unsigned long)data.length,maxLength);
+    if (data.length < maxLength) return data;
+
+    UIImage *image = [UIImage imageWithData:imageData];
+    CGFloat max = 1;
+    CGFloat min = 0;
+    for (int i = 0; i < 6; ++i) {
+        compression = (max + min) / 2;
+        data = UIImageJPEGRepresentation(image, compression);
+        if (data.length < maxLength * 0.9) {
+            min = compression;
+        } else if (data.length > maxLength) {
+            max = compression;
+        } else {
+            break;
+        }
+    }
+
+    NSLog(@"压缩第一次 %lu  %lu  ",(unsigned long)data.length,maxLength);
+    if (data.length < maxLength) return data;
+
+    UIImage *resultImage;
+
+    resultImage = [UIImage imageWithData:data];
+
+    // Compress by size
+    NSUInteger lastDataLength = 0;
+    while (data.length > maxLength && data.length != lastDataLength) {
+        lastDataLength = data.length;
+        CGFloat ratio = (CGFloat) maxLength / data.length;
+        CGSize size = CGSizeMake((NSUInteger) (resultImage.size.width * sqrtf(ratio)),
+                (NSUInteger) (resultImage.size.height * sqrtf(ratio))); // Use NSUInteger to prevent white blank
+        UIGraphicsBeginImageContext(size);
+        [resultImage drawInRect:CGRectMake(0, 0, size.width, size.height)];
+        resultImage = UIGraphicsGetImageFromCurrentImageContext();
+        UIGraphicsEndImageContext();
+        data = UIImageJPEGRepresentation(resultImage, compression);
+    }
+
+    NSLog(@"压缩第二次%lu  %lu  ",(unsigned long)data.length,maxLength);
+    return data;
+}
+
 + (UIImage *)compressImage:(UIImage *)image toByte:(NSUInteger)maxLength isPNG:(BOOL)isPNG {
     // Compress by quality
     CGFloat compression = 1;
@@ -83,4 +130,4 @@ - (UIImage *)scaleFromImage:(UIImage *)image width:(CGSize)newSize {
     UIGraphicsEndImageContext();
     return newImage;
 }
-@end
+@end