如何在Objective-C(iOS)中的图像上写文字? [英] How to write text on image in Objective-C (iOS)?
问题描述
我想以编程方式制作这样的图片:
I want to make an image like this programmatically:
我有上面的图像和文字。我应该在图像上写文字吗?
I have the upper image and text with me. Should I write text on the image?
我想让它成为一个完整的.png图像(图像+标签)并将其设置为按钮的背景。
I want to make it a complete .png image(image + label) and set it as the background of the button.
推荐答案
在图像中绘制文本并返回结果图像:
Draw text inside an image and return the resulting image:
+(UIImage*) drawText:(NSString*) text
inImage:(UIImage*) image
atPoint:(CGPoint) point
{
UIFont *font = [UIFont boldSystemFontOfSize:12];
UIGraphicsBeginImageContext(image.size);
[image drawInRect:CGRectMake(0,0,image.size.width,image.size.height)];
CGRect rect = CGRectMake(point.x, point.y, image.size.width, image.size.height);
[[UIColor whiteColor] set];
[text drawInRect:CGRectIntegral(rect) withFont:font];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
用法:
// note: replace "ImageUtils" with the class where you pasted the method above
UIImage *img = [ImageUtils drawText:@"Some text"
inImage:img
atPoint:CGPointMake(0, 0)];
将图像内部文本的原点从0,0更改为您喜欢的任何位置。
Change the origin of the text inside the image from 0,0 to whatever point you like.
要在文本后面绘制一个纯色矩形,请在行 [[UIColor whiteColor] set]之前添加以下内容;
:
To paint a rectangle of solid color behind the text, add the following before the line [[UIColor whiteColor] set];
:
[[UIColor brownColor] set];
CGContextFillRect(UIGraphicsGetCurrentContext(),
CGRectMake(0, (image.size.height-[text sizeWithFont:font].height),
image.size.width, image.size.height));
我使用文字大小来计算纯色矩形的原点,但你可以更换它有任何数字。
I'm using the text size to calculate the origin for the solid color rectangle, but you can replace it with any number.
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