View not visible

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As a developer, it’s frustrating when we encounter issues with our views not being displayed correctly. In this article, we’ll explore the problem of a table view not being visible and provide a step-by-step solution to resolve it.

Problem Statement

The issue is that when we start the application with TaskRootController as the root view controller of UINavigationController, only the title from TaskRootController is displayed, along with the background color. However, the table view is not visible.

On the other hand, when we start the application with TaskRootController as the rootViewController, the table view is displayed correctly.

Background

To understand why this issue occurs, let’s dive into the world of view controllers and their life cycles.

In iOS development, a view controller represents a view that can be managed by the system. When an application starts, the system creates an instance of the root view controller, which is responsible for managing the main window of the app.

UINavigationController is a type of view controller that manages a stack of views. It provides a way to navigate between different views using buttons or other interactive elements.

UIViewController is another type of view controller that can contain additional views, such as UITableView.

When we create an instance of TaskRootController, it becomes the root view controller of our application.

Solution

To make the table view visible when starting the application with TaskRootController as the root view controller, we need to implement the following steps:

Step 1: Add Delegates and Data Sources

In the TaskRootController.h file, we need to add the delegates and data sources for UITableView. This is done by implementing the UITableViewDataSource and UITableViewDelegate protocols.

@interface TaskRootController : UIViewController <UITableViewDataSource, UITableViewDelegate>

Step 2: Create the Table View

In the TaskRootController.m file, we need to create an instance of UITableView and add it as a subview to our view controller’s main view. We also need to set the delegate and data source for the table view.

self.tblView = [[UITableView alloc] initWithFrame:self.view.bounds size:UITableViewStyleGrouped];
[self.tblView.delegate = self];
[self.tblView.dataSource = self];
[self.view addSubview:self.tblView];

Step 3: Implement Delegate and Data Source Methods

We need to implement the delegate and data source methods for UITableView. This includes methods like numberOfSectionsInTableView:, tableView:numberOfRowsInSection:, and others.

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    return 1; // put number for section.
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return 6; // put number as you want row in section.
}

Conclusion

In this article, we explored the issue of a table view not being visible when starting an application with TaskRootController as the root view controller. We discussed the importance of delegates and data sources for UITableView and provided step-by-step solutions to resolve the issue.

By following these steps, you should be able to make your table view visible when starting an application with TaskRootController as the root view controller.

Additional Tips

When working with UINavigationController, it’s essential to understand its life cycle and how it affects our app.
Delegates and data sources play a crucial role in iOS development, especially when working with views like UITableView.
Implementing delegate and data source methods correctly can make a significant difference in the performance and behavior of your app.

Common Issues

Some common issues that might occur when dealing with table views include:

Table view not showing up: This could be due to missing delegates or data sources, incorrect layout constraints, or insufficient memory.
Table view rows not displaying correctly: This might be caused by incorrect row height calculations, insufficient data source methods implementation, or issues with the table view’s layout.
Error messages in Xcode: Make sure to check your code for any syntax errors, missing imports, or incompatible frameworks.

By being aware of these common issues and taking the necessary steps to resolve them, you can create a more robust and efficient iOS app.

Last modified on 2023-08-29