加入ctrundelegate 的回调

_posts/2013/2013-03-11-core-text.md

@@ -161,6 +161,25 @@ callbacks的结构体为CTRunDelegateCallbacks，主要是包含一些回调函
 
 {% highlight objc %}
 
+void RunDelegateDeallocCallback( void* refCon ){
+    
+}
+
+CGFloat RunDelegateGetAscentCallback( void *refCon ){
+    NSString *imageName = (NSString *)refCon;
+    return [UIImage imageNamed:imageName].size.height;
+}
+
+CGFloat RunDelegateGetDescentCallback(void *refCon){
+    return 0;
+}
+
+CGFloat RunDelegateGetWidthCallback(void *refCon){
+    NSString *imageName = (NSString *)refCon;
+    return [UIImage imageNamed:imageName].size.width;
+}
+
+
 - (void)drawRect:(CGRect)rect
 {
     CGContextRef context = UIGraphicsGetCurrentContext();