C# 如何在没有选择开始的情况下设置文本框光标位置
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How to set TextBox cursor position without SelectionStart
提问by walruz
I have a Windows Forms textbox with background thread updating its value every second. If I place cursor inside textbox it will loose its current position at next update. Same thing with text selection.
我有一个 Windows 窗体文本框，后台线程每秒更新其值。如果我将光标放在文本框中，它将在下次更新时失去当前位置。与文本选择相同。
I tried to solve it like that
我试着这样解决
protected void SetTextProgrammatically(string value)
{
// save current cursor position and selection
int start = textBox.SelectionStart;
int length = textBox.SelectionLength;
// update text
textBox.Text = value;
// restore cursor position and selection
textBox.SelectionStart = start;
textBox.SelectionLength = length;
}
It works good most of the time. Here is situation when it does not work:
1) I place cursor at the end of the text in textbox
2) press SHIFT and move cursor to the left using <- arrow key
Selection won't work properly.
大多数情况下它运行良好。这是它不起作用的情况：
1) 我将光标放在文本框中文本的末尾
2) 按 SHIFT 并使用 <- 箭头键将光标向左移动
选择将无法正常工作。
It looks like combination SelectionStart=10and SelectionLength=1automatically moves cursor to position 11 (not 10 as I want it to be).
它看起来像组合SelectionStart=10并SelectionLength=1自动将光标移动到位置 11（不是我想要的 10）。
Please let me know if there is anything I can do about it! I am using Framework.NET 2.0.
There must be a way to set cursor position in textbox other then SelectionStart+SelectionLength.
如果有什么我可以做的，请告诉我！我正在使用 Framework.NET 2.0。
必须有一种方法可以在文本框中设置光标位置，而不是SelectionStart+SelectionLength.
采纳答案by walruz
I have found the solution!
我找到了解决办法！
// save current cursor position and selection
int start = textBox.SelectionStart;
int length = textBox.SelectionLength;
Point point = new Point();
User32.GetCaretPos(out point);
// update text
textBox.Text = value;
// restore cursor position and selection
textBox.Select(start, length);
User32.SetCaretPos(point.X, point.Y);
Now its working just like it should.
现在它的工作就像它应该的那样。
回答by Stefano Altieri
//save position
bool focused = textBox1.Focused;
int start = textBox1.SelectionStart;
int len = textBox1.SelectionLength;
//do your work
textBox1.Text = "duviubobioub";
//restore
textBox1.SelectionStart = start;
textBox1.SelectionLength = len ;
textBox1.Select();
回答by S.Sathish Kumar
To set the cursor position in textbox without selection start...!
在没有选择的情况下在文本框中设置光标位置开始...！
textbox1.Select(textbox1.text.length,0); /* ===> End of the textbox */
textbox1.Select(0,0); /* ===> Start of the textbox */
