1.判断字符串为空和只为空格解决办法
+ (BOOL)isBlankString:(NSString *)string
{
if (string == nil) {
return YES;
}
if (string == NULL) {
return YES;
}
if ([string isKindOfClass:[NSNull class]]) {
return YES;
}
if ([[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] length]==0) {
return YES;
}
if ([[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] isEqualToString:@"null"]||[[string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] isEqualToString:@"(null)"]) {
return YES;
}
return NO;
}
2.限制textfiled 文字字数（textview同理）
+ (void)limitTextField:(UITextField *)textField limitNum:(NSUInteger)num
{
/**
* 最大输入长度,中英文字符都按一个字符计算
*/
UITextField *textfield = textField;
NSString *toBeString = textfield.text;
// 获取键盘输入模式
NSString *lang = textfield.textInputMode.primaryLanguage;
// 中文输入的时候,可能有markedText(高亮选择的文字),需要判断这种状态
// zh-Hans表示简体中文输入, 包括简体拼音，健体五笔，简体手写
if ([lang isEqualToString:@"zh-Hans"]) {
UITextRange *selectedRange = [textfield markedTextRange];
//获取高亮选择部分
UITextPosition *position = [textfield positionFromPosition:selectedRange.start offset:0];
// 没有高亮选择的字，表明输入结束,则对已输入的文字进行字数统计和限制
if (!position) {
if (toBeString.length > num) {
// 截取子串
textfield.text = [toBeString substringToIndex:num];
}
}
} else {
// 中文输入法以外的直接对其统计限制即可，不考虑其他语种情况
if (toBeString.length > num) {
// 截取子串
textfield.text = [toBeString substringToIndex:num];
}
}
}
3.判断时间 1过期 0相等 -1没过期
+(int)compareOneDay:(NSDate *)oneDay withAnotherDay:(NSDate *)anotherDay
{
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"yyyy-MM-dd hh:mm:ss"];
NSString *oneDayStr = [dateFormatter stringFromDate:oneDay];
NSString *anotherDayStr = [dateFormatter stringFromDate:anotherDay];
NSDate *dateA = [dateFormatter dateFromString:oneDayStr];
NSDate *dateB = [dateFormatter dateFromString:anotherDayStr];
NSComparisonResult result = [dateA compare:dateB];
NSLog(@"oneDay : %@, anotherDay : %@", oneDay, anotherDay);
if (result == NSOrderedDescending) {
//在指定时间前面 过了指定时间 过期
NSLog(@"oneDay is in the future");
return 1;
}
else if (result == NSOrderedAscending){
//没过指定时间 没过期
//NSLog(@"Date1 is in the past");
return -1;
}
//刚好时间一样.
//NSLog(@"Both dates are the same");
return 0;
}
5.相机获取到的图片自动旋转90度解决办法
+ (UIImage *)fixOrientation:(UIImage *)aImage {
if (aImage.imageOrientation == UIImageOrientationUp)
return aImage;
CGAffineTransform transform = CGAffineTransformIdentity;
switch (aImage.imageOrientation) {
case UIImageOrientationDown:
case UIImageOrientationDownMirrored:
transform = CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height);
transform = CGAffineTransformRotate(transform, M_PI);
break;
case UIImageOrientationLeft:
case UIImageOrientationLeftMirrored:
transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
transform = CGAffineTransformRotate(transform, M_PI_2);
break;
case UIImageOrientationRight:
case UIImageOrientationRightMirrored:
transform = CGAffineTransformTranslate(transform, 0, aImage.size.height);
transform = CGAffineTransformRotate(transform, -M_PI_2);
break;
default:
break;
}
switch (aImage.imageOrientation) {
case UIImageOrientationUpMirrored:
case UIImageOrientationDownMirrored:
transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
transform = CGAffineTransformScale(transform, -1, 1);
break;
case UIImageOrientationLeftMirrored:
case UIImageOrientationRightMirrored:
transform = CGAffineTransformTranslate(transform, aImage.size.height, 0);
transform = CGAffineTransformScale(transform, -1, 1);
break;
default:
break;
}
CGContextRef ctx = CGBitmapContextCreate(NULL, aImage.size.width, aImage.size.height,
CGImageGetBitsPerComponent(aImage.CGImage), 0,
CGImageGetColorSpace(aImage.CGImage),
CGImageGetBitmapInfo(aImage.CGImage));
CGContextConcatCTM(ctx, transform);
switch (aImage.imageOrientation) {
case UIImageOrientationLeft:
case UIImageOrientationLeftMirrored:
case UIImageOrientationRight:
case UIImageOrientationRightMirrored:
// Grr...
CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.height,aImage.size.width), aImage.CGImage);
break;
default:
CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.width,aImage.size.height), aImage.CGImage);
break;
}
// And now we just create a new UIImage from the drawing context
CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
UIImage *img = [UIImage imageWithCGImage:cgimg];
CGContextRelease(ctx);
CGImageRelease(cgimg);
return img;
}
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