cell | 易学教程

优化UITableView性能

阅读更多关于优化UITableView性能

在iOS应用中，UITableView应该是使用率最高的视图之一了。iPod、时钟、日历、备忘录、Mail、天气、照片、电话、短信、 Safari、App Store、iTunes、Game Center⋯几乎所有自带的应用中都能看到它的身影，可见它的重要性。然而在使用第三方应用时，却经常遇到性能上的问题，普遍表现在滚动时比较卡，特别是table cell中包含图片的情况时。实际上只要针对性地优化一下，这种问题就不会有了。有兴趣的可以看看 LazyTableImages 这个官方的例子程序，虽然也要从网上下载图片并显示，但滚动时丝毫不卡。下面就说说我对UITableView的了解。不过由于我也是初学者，或许会说错或遗漏一些，因此仅供参考。首先说下UITableView的原理。有兴趣的可以看看《About Table Views in iOS-Based Applications》。 UITableView是UIScrollView的子类，因此它可以自动响应滚动事件（一般为上下滚动）。它内部包含0到多个UITableViewCell对象，每个table cell展示各自的内容。当新cell需要被显示时，就会调用tableView:cellForRowAtIndexPath:方法来获取或创建一个 cell；而不可视时，它又会被释放。由此可见

Table View Cells changing colors when scrolling Swift

阅读更多关于 Table View Cells changing colors when scrolling Swift

问题 I'm making an app that uses colored table view cells to separate other cells into categories. I am doing this by coloring the cells different colors using if else statements. But for some reason, when I launch the app, the more I scroll up and down on the table view, the more other cells randomly change color too. This is the code in my custom instrumentTableCell class: @IBOutlet var nameLabel: UILabel? @IBOutlet var descriptionLabel: UILabel? @IBOutlet var thumbnailImage: UIImageView! func

Interaction with a cell renderer in JTable

阅读更多关于 Interaction with a cell renderer in JTable

问题 Is there any way to get a cell renderer to respond to mouse events, such as mouseovers? 回答1: Never tried it but I guess you would need to: a) create a custom renderer to paint the cell in two states b) you need to keep track of which cell should currently be painted in the "mouse over" state c) add a mouse listener to track mouse entered/exited and mouseMoved. With each event you would need to update a variable that tracks which cell the mouse is positioned over. You can use the columnAtPoint

jQuery: How to select the values from the table's column based on tables header only

阅读更多关于 jQuery: How to select the values from the table's column based on tables header only

问题 I have a table with header ID. I need to select all the fields under this header. I don't have access to the source code and no classes are used in this table. Any idea on how to get this done? 回答1: To get the first column: $(function() { var col = $("td:nth-child(1)"); }); 回答2: Most straightforward would be to get the position (index) of the header in the row and then access the value of all cells at the same column index. $('#table th').click(function() { var th = $(this); var index = $('th

How to set bitmap image to Button Background Image

阅读更多关于 How to set bitmap image to Button Background Image

问题 gridcell = (Button) row.findViewById(R.id.calendar_day_gridcell); gridcell.setText("Day 1"); URL url = new URL("http://172.16.4.29:81/pht/2013/9/18/3027_2013_9_18_12_14_56_b.JPG"); Bitmap bmp = BitmapFactory.decodeStream(url.openConnection().getInputStream()); How can I set bitmap bmp image to button gridcells background Image? 回答1: You can use following code to do that.. BitmapDrawable bdrawable = new BitmapDrawable(context.getResources(),bitmap); then just set bitmap with below function

UIImageView in custom UITableViewCell not respecting Aspect Fit mode

阅读更多关于 UIImageView in custom UITableViewCell not respecting Aspect Fit mode

问题 I have a table view that uses a custom UITableViewCell that I created on a NIB. In this custom cell I have a square image view to show logos. The images are already thumbnail-size but they have different sizes (some are squares and some are not). I simply specified my UIImage in my custom cell to have a View Mode of "Aspect Fit", so as to make all of them display on a square but without losing their aspect ratio. The problem is that I keep getting an image that fills the height of my row and

How do I get rid of double quotes in a Matlab cell?

阅读更多关于 How do I get rid of double quotes in a Matlab cell?

问题 I have an array of cells in Matlab that all elements in the cell are expressed as: '"something"' How can I create an array of 'something' ? 回答1: Here are two solutions. strrep removes all instances of double quotes, while regexprep only removes double quotes at the start and end of the string (thanks to Gunther Struyf for pointing out that the second regexprep solution would be needed in some scenarios): >> A = {'"hello"', '"wor"ld"'} A = '"hello"' '"wor"ld"' >> B = strrep(A, '"', '') B =

TCPDF: Clip text to Cell width

阅读更多关于 TCPDF: Clip text to Cell width

问题 I am generating PDF report using TCPDF's Cell method extensively. Text printed with Cell method spills beyond width specified in method. I want to print only as much part of the text that fits in the specified width but not to spill beyond or wrap to next line. I do not want font stretch strategy. I searched a lot but could not find a solution. Is there any other method/way to handle this? (I used setfillcolor(255) to achieve the visual effect. But the text is still there, invisible; gets

springMVC生成pdf文件

阅读更多关于 springMVC生成pdf文件

pom.xml文件配置===  <dependency> <groupId>com.itextpdf</groupId> <artifactId>itextpdf</artifactId> <version>5.5.13</version> </dependency>  <dependency> <groupId>com.itextpdf</groupId> <artifactId>itext-asian</artifactId> <version>5.2.0</version> </dependency> 建立第一个PDF文档：一、主要步骤（5个）： 1.新建document对象，可通过一下三种任意一种 Document document =new Document(); // 默认页面大小是A4 Document document =new Document(PageSize.A4); // 指定页面大小为A4 Document document =new Document(PageSize.A4,50,50,30

Select or Copy 3 non-adjacent cells

阅读更多关于 Select or Copy 3 non-adjacent cells

问题 How can I copy 3 non-adjacent cells using ActiveCell.Row ? Range("A" & ActiveCell.Row, "C" & ActiveCell.Row, "E" & ActiveCell.Row).Copy 回答1: To simplify things a little: Range(Replace("A?,C?,E?", "?", ActiveCell.Row)).Copy 回答2: You have the , outside the "" . You need to put them inside. See this Range("A" & ActiveCell.Row & ",C" & ActiveCell.Row & ",E" & ActiveCell.Row).Copy 回答3: Try this: Union(Cells(ActiveCell.Row, 1), Cells(ActiveCell.Row, 3), Cells(ActiveCell.Row, 5)).Copy 回答4: I think