Merge pull request #1238 from kinarobin/optimize_request_operation

[Enhancements] Optimize request operation

TZImagePickerController/TZImagePickerController/TZImageRequestOperation.m

@@ -26,26 +26,24 @@
 
 - (void)start {
     self.executing = YES;
-    dispatch_async(dispatch_get_global_queue(0, 0), ^{
-        [[TZImageManager manager] getPhotoWithAsset:self.asset completion:^(UIImage *photo, NSDictionary *info, BOOL isDegraded) {
-            dispatch_async(dispatch_get_main_queue(), ^{
-                if (!isDegraded) {
-                    if (self.completedBlock) {
-                        self.completedBlock(photo, info, isDegraded);
-                    }
-                    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
-                        [self done];
-                    });
+    [[TZImageManager manager] getPhotoWithAsset:self.asset completion:^(UIImage *photo, NSDictionary *info, BOOL isDegraded) {
+        dispatch_async(dispatch_get_main_queue(), ^{
+            if (!isDegraded) {
+                if (self.completedBlock) {
+                    self.completedBlock(photo, info, isDegraded);
                 }
-            });
-        } progressHandler:^(double progress, NSError *error, BOOL *stop, NSDictionary *info) {
-            dispatch_async(dispatch_get_main_queue(), ^{
-                if (self.progressBlock) {
-                    self.progressBlock(progress, error, stop, info);
-                }
-            });
-        } networkAccessAllowed:YES];
-    });
+                dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
+                    [self done];
+                });
+            }
+        });
+    } progressHandler:^(double progress, NSError *error, BOOL *stop, NSDictionary *info) {
+        dispatch_async(dispatch_get_main_queue(), ^{
+            if (self.progressBlock) {
+                self.progressBlock(progress, error, stop, info);
+            }
+        });
+    } networkAccessAllowed:YES];
 }
 
 - (void)done {