[英]UWP C# Scroll to the bottom of TextBox
如何滾動到UWP應用的文本框底部?
隨着我的過渡到UWP,這一直是尚未直截了當的問題之一。
我曾經可以使用這樣的:
textBox.SelectionStart = textBox.TextLength;
textBox.ScrollToCaret();
但是,這不適用於UWP應用
使用https://code.msdn.microsoft.com/windowsapps/How-to-scroll-to-the-a8ea5867中的答案有時會導致向上滾動時刪除行。
要解決此問題,請嘗試以下操作:
private void ScrollToBottom(TextBox textBox)
{
var grid = (Grid)VisualTreeHelper.GetChild(textBox, 0);
for (var i = 0; i <= VisualTreeHelper.GetChildrenCount(grid) - 1; i++)
{
object obj = VisualTreeHelper.GetChild(grid, i);
if (!(obj is ScrollViewer)) continue;
((ScrollViewer)obj).ChangeView(0.0f, ((ScrollViewer)obj).ExtentHeight, 1.0f, true);
break;
}
}
主要區別是此行:
((ScrollViewer)obj).ChangeView(0.0f, ((ScrollViewer)obj).ExtentHeight, 1.0f, true);
我也將方法與事件處理程序分開,因為我不想每次更改文本時都必須滾動。
如果有人需要滾動到UWP應用程序中TextBox的底部,請執行以下操作:
https://code.msdn.microsoft.com/windowsapps/How-to-scroll-to-the-a8ea5867
private void TextBox_TextChanged(object sender, TextChangedEventArgs e)
{
var grid = (Grid)VisualTreeHelper.GetChild(textBox1, 0);
for (var i = 0; i <= VisualTreeHelper.GetChildrenCount(grid) - 1; i++)
{
object obj = VisualTreeHelper.GetChild(grid, i);
if (!(obj is ScrollViewer)) continue;
((ScrollViewer)obj).ChangeView(0.0f, ((ScrollViewer)obj).ExtentHeight, 1.0f);
break;
}
}
}
其中,textBox1是要滾動到底部的TextBox。
等效於C ++ / CX中的先前答案:
using Windows::UI::Xaml::Media::VisualTreeHelper;
using Windows::UI::Xaml::Controls::Grid;
using Windows::UI::Xaml::Controls::ScrollViewer;
using Platform::Object;
void
MainPage::responseTextUpdated(Platform::Object^ sender, Windows::UI::Xaml::RoutedEventArgs^ e)
{
Grid^ grid = static_cast<Grid^>(VisualTreeHelper::GetChild(responseText, 0));
for (int i = 0; i < VisualTreeHelper::GetChildrenCount(grid); ++i)
{
Object^ child = VisualTreeHelper::GetChild(grid, i);
ScrollViewer^ scrollViewer = dynamic_cast<ScrollViewer^>(child);
if (scrollViewer == nullptr) continue;
double const horizontalOffset = 0;
double const verticalOffset = scrollViewer->ExtentHeight;
float const zoomFactor = 1;
scrollViewer->ChangeView(horizontalOffset, verticalOffset, zoomFactor);
break;
}
}
其中responseText是TextBox^ responseText
,您要滾動的TextBox(可能與發件人相同)。
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