IOS开发常用代码汇总2

11.根据文件名，返回UIImage对象
+ (UIImage*)getLocalImageByName:(NSString*)picName
{
NSString *path      = [[NSBundle
mainBundle] pathForResource:picName
ofType:nil];
    // return [UIImage imageWithContentsOfFile:path];
UIImage *tempImage = [UIImage
imageWithContentsOfFile:path];
if (tempImage ==
nil) {
tempImage = [[UIImage
alloc] init];
}
return tempImage;
    
}
12.创建一个带有事件的UIButton
    //创建“发送”按钮
    UILabel *nameLabel;
    UIButton *sendBtn = [UIButton
buttonWithType:UIButtonTypeCustom];
    [sendBtn setFrame:CGRectMake(260,
7, 50,
30)];
[sendBtn setImage:[11
getLocalImageByName:@"send_bt.png"]
forState:UIControlStateNormal];
[sendBtn setImage:[11
getLocalImageByName:@"send_end.png"]
forState:UIControlStateHighlighted];
    [sendBtn addTarget:self
action:@selector(sendFeedback)
forControlEvents:UIControlEventTouchUpInside];
    [self.view
addSubview:sendBtn];

13.根据RGB和Alpha返回UIColor
(UIColor *) colorFromHexRGB:(NSString *)inColorString inAlpha:(CGFloat)AlphaValue
{
    UIColor *result =
nil;
unsigned
int colorCode = 0;
unsigned
char redByte, greenByte, blueByte;

if (nil != inColorString)
{
NSScanner *scanner = [NSScanner
scannerWithString:inColorString];
(void) [scanner
scanHexInt:&colorCode];
// ignore error
}
redByte = (unsigned
char) (colorCode >> 16);
greenByte = (unsigned
char) (colorCode >> 8);
blueByte = (unsigned
char) (colorCode); // masks off high bits
result = [UIColor
              colorWithRed:(float)redByte/
0xff
              green:
(float)greenByte/ 0xff
              blue:
(float)blueByte
/ 0xff
              alpha:AlphaValue];
//0xff
return result;
}
14.设置圆角UITextView，显示键盘
    [self.contantTextView
becomeFirstResponder];
    self.contantTextView.delegate=self;
self.contantTextView.layer.cornerRadius =
6;
self.contantTextView.layer.masksToBound
a96f
s =
YES;
15.键盘隐藏
    [self.contantTextView  resignFirstResponder];
16. 通常使用Documents目录进行数据持久化的保存，而这个Documents目录可以通过下面方法获得
     NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
17.弹出视图和消失视图

        弹出：
        FeedbackViewController *ctller = [[FeedbackViewController alloc]init];
         ctller.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
        [self presentModalViewController:ctller animated:YES];
        消失：
        [self dismissModalViewControllerAnimated:YES];
18.navigationController视图切换和返回
     切换：
    LoginViewController *ctller = [[LoginViewController alloc]init];
[self.navigationController pushViewController:ctller animated:YES];
[ctller release];
     返回：
          [self.navigationController popToRootViewControllerAnimated:YES];

19.新建一个弹出框
              UIAlertView *alert = [[UIAlertView alloc]
                                  initWithTitle:@"提示"
                                  message:@"这是一个测试"
                                  delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil];
            [alert show];
            [alert release];
20.新建一个多选项的弹出框
        UIAlertView *alert = [[UIAlertView alloc]
                          initWithTitle:@"提示"
                          message:@"这也是一个测试"
                          delegate:self cancelButtonTitle:@"确认" otherButtonTitles:@"取消",nil];
    [alert setTag:2];
    [alert show];
    [alert release];