xcode 6.1
File-New-Project..
iOs-Application-Simple View Application
1、写一个自定义JSTextField类，继承UITextField,来重载原有的initWithFrame方法，以便以后可以重用。
1.1右键，弹的菜单New File...
1.2 iOS-Source-Cocoa Touch Class
1.3 在Class:中输入JSTextField(名字自取),让其继承UITextField:
1.4 Next =>Create 创建文件JSTextField.h JSTextField.m
1.5 点击JSTextField.h,输入方法：
代码：
-(id)initWithFrame:(CGRect)frame drawingLeft:(UIImageView*)icon;
1.6 打开JSTextField.m,实现initWithFrame方法，并且overwrite方法leftViewRectForBounds:,让图标右侧可以有点间距:
代码：
#import "JSTextField.h"
@implementation JSTextField
-(id)initWithFrame:(CGRect)frame drawingLeft:(UIImageView *)icon{
self = [super initWithFrame:frame];
if (self) {
self.leftView = icon;
self.leftViewMode = UITextFieldViewModeAlways;
}
return self;
}
-(CGRect)leftViewRectForBounds:(CGRect)bounds{
CGRect iconRect = [super leftViewRectForBounds:bounds];
iconRect.origin.x += ;// 右偏10
return iconRect;
}
@end
2、使用刚才的JSTextField:
代码：
UIImage *usernameImage = [UIImage imageNamed:@"20.gif"];
UIImageView *usernameIcon = [[UIImageView alloc] initWithImage:usernameImage];
usernameIcon.frame = CGRectMake(, , , ); self.textview = [[JSTextField alloc] initWithFrame:CGRectMake(, , , ) drawingLeft:usernameIcon];
self.textview.placeholder = @"用户名";
self.textview.borderStyle = UITextBorderStyleRoundedRect;
self.textview.clearButtonMode = UITextFieldViewModeWhileEditing;
//[self.textview setKeyboardType:UIKeyboardTypeNumbersAndPunctuation];
[self.view addSubview:self.textview];
textview的声明，在ViewController.h中：
代码：
@property (strong, nonatomic) IBOutlet JSTextField *textview;
效果如下：