How to clear previous text in UITextView before writing text?

I want to clear previous text written on UITextView before new text is written on it. I did like this.

textView.text = @"";
textView.text = @"something";

But, previous text is not cleared. It overlaps with current text. Textview开发者_StackOverflow社区 is non-editable.

You need to implement the UITextViewDelegate and the method, textViewDidBeginEditing. The following code sets the textView's text to @"" (nothing) when it starts editing.

- (void) textViewDidBeginEditing:(UITextView *) textView {
  [textView setText:@""];
}

Here is a code for swift

func textViewDidBeginEditing(textView: UITextView) {
        txtView.text = ""
        txtView.textColor = UIColor.blackColor()
    }

func textViewDidEndEditing(textView: UITextView) {
     if txtView.text.isEmpty {
         txtView.text = "Write your comment."
         txtView.textColor = UIColor.blackColor()
     }
}

func textView(textView: UITextView, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
        if text == "\n"  // Recognizes enter key in keyboard
        {
            textView.resignFirstResponder()
            return false
        }
        return true
    }

Note : give delegate to your textview

Set the selected range to the entire text of the textView first:

    [textView setSelectedRange:NSMakeRange(0, textView.text.length)];
    [textView setText:@""];

As in:

- (BOOL)textViewShouldBeginEditing:(UITextView *)textView {
    //  Make the textView visible in-case the keyboard has covered it
    [table scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:1] 
                 atScrollPosition:UITableViewScrollPositionTop 
                         animated:YES];

    // Keyboard toolbar prev/next buttons
    [nextPreviousControl setEnabled:YES forSegmentAtIndex:0];
    [nextPreviousControl setEnabled:NO forSegmentAtIndex:1];

    //
    // Erase all text in the textView before editing starts:
    // 
    [textView setSelectedRange:NSMakeRange(0, textView.text.length)];
    [textView setText:@""];
    return YES;
}

Set the clearsOnBeginEditing for your text field.