在 UItextview 开始时移动光标 [英] Moving cursor at beginning UItextview

问题描述

可能的重复:
将光标移动到 UITextField 的开头

您好，我有一个带有文本的文本视图 我想在开始时移动光标位置 我使用了 NSMakeRange 但我不知道为什么它不起作用.我写过 NSMakeRange is different places ，希望它至少运行一次但没有用.这是代码.提前谢谢

Hello i have a textview with text I want to move cursor position at beginning I have use NSMakeRange but i don't know why its not working. I have written NSMakeRange is different places , hoping that it would run atleast once but didn't work. Here is the code. thx in advance

- (void)viewDidLoad
{
    [super viewDidLoad];    
    apnatxtView.textColor=[UIColor lightGrayColor];
    apnatxtView.text=@"Description goes here";
    totalLenght=apnatxtView.text.length;
     apnatxtView.selectedRange=NSMakeRange(0,0);    
}


- (BOOL)textViewShouldBeginEditing:(UITextView *)textView{

apnatxtView.selectedRange=NSMakeRange(0,0);  
    return YES;


}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{

    [apnatxtView resignFirstResponder];

}

- (void)textViewDidChange:(UITextView *)textView{


    if (apnatxtView.text.length == 0) {
        apnatxtView.textColor= [UIColor lightGrayColor];
        apnatxtView.text=@"Description goes here";
        apnatxtView.selectedRange=NSMakeRange(0, 0);
    }



}

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{


    if (apnatxtView.textColor == [UIColor lightGrayColor]) {
        apnatxtView.textColor=[UIColor blackColor];
       // apnatxtView.text=@"Description goes here";
        apnatxtView.text=nil;
        return YES;
    }

}

推荐答案

这适用于我在 iOS 6.0 模拟器上的测试:

This works in my testing on the iOS 6.0 simulator:

- (void)textViewDidBeginEditing:(UITextView *)textView {
    dispatch_async(dispatch_get_main_queue(), ^{
        textView.selectedRange = NSMakeRange(0, 0);
    });
}

我猜它会根据触摸位置更新选择之后它发送textViewDidBeginEditing:消息.dispatch_async 可以解决这个问题.

I guess it updates the selection based on the touch location after it sends the textViewDidBeginEditing: message. The dispatch_async works around that.

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