我写了一个接口“myDrawInRect”来替换NSString中的原始“drawInRect”。
代码如下:
.h文件:
@interface NSString(TextDrawing)
-(CGSize) myDrawInRect:(CGRect)rect withFont:(UIFont *)font textColor:(UIColor*)textColor
lineBreakMode:(NSLineBreakMode)lineBreakMode alignment:(NSTextAlignment)alignment;
@end
.m文件:
@interface NSString(TextDrawing)
-(CGSize) myDrawInRect:(CGRect)rect withFont:(UIFont *)font textColor:(UIColor*)textColor
lineBreakMode:(NSLineBreakMode)lineBreakMode alignment:(NSTextAlignment)alignment
{
CGFloat screen_scale = [UIScreen mainScreen].scale;
CGContextRef bitmapContext = CreateBitmapContext( rect.size.width * screen_scale, rect.size.height * screen_scale );
/* ... some code to draw the bitmapContext; */
CGImageRef image = CGBitmapContextCreateImage( bitmapContext );
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextScaleCTM( context, 1.0f, -1.0f );
CGContextTranslateCTM( context, 0.0f, -CGRectGetHeight(realRect) );
CGContextDrawImage( context, rect, image );
CGContextRelease( bitmapContext );
CGImageRelease( myImage );
}
@end
我在UILabel drawInRect中调用了myDrawInRect,但我在标签上看不到任何内容。 任何人都可以建议吗?谢谢!
答案 0 :(得分:0)
试试这个
CGImageRef image = CGBitmapContextCreateImage( bitmapContext );
CGContextRef context = UIGraphicsGetCurrentContext();
// MODIFY AND ADD FOLLOWING LINES
CGContextTranslateCTM( context, 0.0f, CGRectGetMaxY(realRect)*2 );
CGContextScaleCTM( context, 1.0f, -1.0f );
CGContextDrawImage( context, rect, image );
CGContextScaleCTM( context, 1.0f, -1.0f );
CGContextTranslateCTM( context, 0.0f, -CGRectGetMaxY(realRect)*2 );
// MODIFY UPTO THIS PONIT
CGContextRelease( bitmapContext );
CGImageRelease( myImage );