一.Placeholder 样式更改

方法一:重写drawPlaceholderInRect:(CGRect)rect方法

-(void)drawPlaceholderInRect:(CGRect)rect{
    UIColor *placeholderColor = [UIColor dt_ColorWithString:@"#999999"];//设置颜色
    [placeholderColor setFill];
    CGRect placeholderRect = CGRectMake(rect.origin.x+5, (rect.size.height- self.font.pointSize)/2, rect.size.width, self.font.lineHeight );//设置Placeholder  位置.尺寸
    
    NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
    style.lineBreakMode            = NSLineBreakByTruncatingTail;
    style.alignment                = self.textAlignment;
    NSDictionary *attr             = [NSDictionary dictionaryWithObjectsAndKeys:style,NSParagraphStyleAttributeName, self.font, NSFontAttributeName, placeholderColor, NSForegroundColorAttributeName, nil];//设置Placeholder 样式
    
    [self.placeholder drawInRect:placeholderRect withAttributes:attr];
}

方法二：通过KVC修改Placeholder颜色

    UITextField *textField1 = [[UITextField alloc] init];
    textField1.frame = CGRectMake(textFieldX, CGRectGetMaxY(textField.frame) + padding, viewWidth - 2 * textFieldX, textFieldH);
    textField1.borderStyle = UITextBorderStyleRoundedRect;
    textField1.placeholder = @"请输入占位文字";
    textField1.font = [UIFont systemFontOfSize:14];
    // "通过KVC修改占位文字的颜色"
    [textField1 setValue:[UIColor greenColor] forKeyPath:@"_placeholderLabel.textColor"];
    [self.view addSubview:textField1];

方法三: 修改attributedPlaceholder属性

NSAttributedString *attrString = [[NSAttributedString alloc] initWithString:@"请输入占位文字" attributes:
    @{NSForegroundColorAttributeName:[UIColor redColor],
                 NSFontAttributeName:textField.font
         }];
    textField.attributedPlaceholder = attrString;

二.控制placeHolder的位置

-(CGRect)placeholderRectForBounds:(CGRect)bounds 
{ 
    CGRect inset = CGRectMake(bounds.origin.x+100, bounds.origin.y, bounds.size.width -10, bounds.size.height);//更好理解些 
    return inset; 
}

三. 修改文本展示区域，一般跟editingRectForBounds一起重写

- (CGRect)textRectForBounds:(CGRect)bounds  
{  
    CGRect inset = CGRectMake(bounds.origin.x+10, bounds.origin.y, bounds.size.width-25, bounds.size.height);//更好理解些  
    return inset;  
}  

// 重写来编辑区域，可以改变光标起始位置，以及光标最右到什么地方，placeHolder的位置也会改变  
-(CGRect)editingRectForBounds:(CGRect)bounds  
{  
    CGRect inset = CGRectMake(bounds.origin.x+10, bounds.origin.y, bounds.size.width-25, bounds.size.height);//更好理解些  
    return inset;  
}  

四.UITextField 关于Rect的一些方法介绍

– textRectForBounds:　         //重写来重置文字区域
– drawTextInRect: 　　         //改变绘文字属性.重写时调用super可以按默认图形属性绘制,若自己完全重写绘制函数，就不用调用super了.
– placeholderRectForBounds:　　//重写来重置占位符区域
– drawPlaceholderInRect:　　   //重写改变绘制占位符属性.重写时调用super可以按默认图形属性绘制,若自己完全重写绘制函数，就不用调用super了
– borderRectForBounds:　　     //重写来重置边缘区域
– editingRectForBounds:　　    //重写来重置编辑区域
– clearButtonRectForBounds:　　//重写来重置clearButton位置,改变size可能导致button的图片失真
– leftViewRectForBounds:      // leftView 的位置
– rightViewRectForBounds:     //  rightView的位置