ios - DrawText on Image with text 调整到图像的大小

Question

我正在图像上绘制文本。文本绘制没有任何问题，但我的文本是动态的，有时它的字符更多，有时它更少。

从下图中您可以看到“ 这是超过图像 的 320 宽度的长消息，因为图像 的 没有出现。

我希望所有消息都显示在下一行，因为我的消息是动态的，我想以 320 * 480 大小的图像显示它，这里我显示小图像只是为了测试目的。

这是绘制文本的代码:

-(UIImage *)addText:(UIImage *)img text:(NSString *)text1{

 int w = img.size.width;
 int h = img.size.height;
 //lon = h - lon;
 CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
 CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);
 CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage);
 CGContextSetRGBFillColor(context, 0.0, 0.0, 1.0, 1);

 char* text = (char *)[text1 cStringUsingEncoding:NSASCIIStringEncoding];

 CGContextSelectFont (context, // 3
 "Helvetica-Bold",
 15,
 kCGEncodingMacRoman);
 CGContextSetTextDrawingMode(context, kCGTextFill);
 CGContextSetRGBFillColor(context, 255, 255, 255, 1); 
 CGContextShowTextAtPoint(context, 4, 52, text, strlen(text));
 CGImageRef imageMasked = CGBitmapContextCreateImage(context);
 CGContextRelease(context);
 CGColorSpaceRelease(colorSpace);
 return [UIImage imageWithCGImage:imageMasked];
}

Answer 1

试试这段代码:

lblText.text=[NSString stringWithFormat:@"Put Your Text"];
lblText.font = [UIFont fontWithName:@"Helvetica" size:10.0f];
CGPoint point=lblText.center;
imgview.image =[self drawText:lblText.text inImage:imgview.image atPoint:point];


    //Save it in Document directory for Checking Purpose...
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:@"savedImage.png"];
    UIImage *image1 =   imgview.image; // imageView is my image from camera
    NSData *imageData = UIImagePNGRepresentation(image1);
    [imageData writeToFile:savedImagePath atomically:NO];


 -(UIImage *) drawText:(NSString*) text inImage:(UIImage*)image atPoint:(CGPoint)point
  {
     UIFont *font =lblText.font;;    
     if ([UIScreen instancesRespondToSelector:@selector(scale)]) {
          UIGraphicsBeginImageContextWithOptions(imgview.frame.size, NO, 0.0f);
      } else {
        UIGraphicsBeginImageContext(imgview.frame.size);
      }

       [image drawInRect:CGRectMake(0,0,imgview.frame.size.width,imgview.frame.size.height)];
       CGRect rect = CGRectMake(point.x,point.y,lblText.frame.size.width, lblText.frame.size.height);//Set Frame as per your Requirement 
       [lblText.textColor set];
       [text drawInRect:CGRectIntegral(rect) withFont:font];
       UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();

     return newImage;
 }

我会帮你的。