- iOS Development with Xamarin Cookbook
- Dimitris Tavlikos
- 530字
- 2021-07-16 11:45:06
Debugging our application
This recipe provides information on debugging a Xamarin.iOS app on the simulator.
Getting ready
Xamarin.iOS, in combination with Xamarin Studio, provides a debugger for debugging apps either on the simulator or on the device. In this recipe, we'll see how to use the debugger for debugging Xamarin.iOS apps. Open Xamarin Studio and load the ButtonInput project. Make sure to set the project configuration to Debug | iPhone.
How to do it...
Perform the following steps to debug your application:
- Xamarin Studio supports breakpoints. To activate a breakpoint on a line, click on the space on the left of the line number to set it. Set a breakpoint on the following line in the
ButtonInputViewController.csfile:this.labelStatus.Text = "Button tapped!";
The following screenshot shows what a breakpoint in Xamarin Studio looks like:
- Compile and debug the project by clicking on the Run button or by navigating to Run | Start Debugging on the menu bar. Xamarin Studio's status will display the message Waiting for debugger to connect….
- When the simulator is opened and the app is loaded, watch the information that is provided in the Application Output pad.
- Tap on the app button. Execution will pause and Xamarin Studio will highlight the breakpoint in yellow. Move the mouse over the
labelStatusvariable in the breakpoint line. A window will be displayed with all the evaluated variable's members, as shown in the following screenshot:
- To stop debugging, click on the Stop button in the toolbar.
How it works...
The debugger that is used is called soft debugger. It is called so because it depends on both the runtime and Xamarin Studio, combined to provide one unified debugging platform. When the debugging process starts, Xamarin Studio begins listening for debugging information from the app. The same applies for debugging on both the simulator and the device. When the app executes, it starts sending information back to Xamarin Studio. It then displays that information in the Application Output pad, which is automatically activated. A typical application output when debugging is the information on the assemblies that are loaded, the threads that begin execution, and the breakpoints, if any, that are available.
There's more...
The Console.WriteLine() method can also be used for debugging purposes. The debugger takes care of this and redirects the output of the method to Xamarin Studio's Application Output pad.
When compiling for debugging purposes, the compiler produces larger and slower code. This is because it generates extra code that is needed to provide the appropriate debugging information. That's why, when debugging an app, the execution of the app is much slower than on simple running situations. Before producing a release copy of the app, remember to compile it with the Release | iPhone project configuration to avoid slow runtime execution.
One more reason for not to have complicated code in the FinishedLaunching method is that, in most cases, you will not be able to debug it. If you set a breakpoint in FinishedLaunching, app execution will pause, but iOS will terminate the app when the time limit is reached.
See also
- The Creating profiles recipe in Chapter 14, Deploying
- Getting Started with Gulp（Second Edition）
- 兩周自制腳本語言
- R語言游戲數據分析與挖掘
- Learn Scala Programming
- Java軟件開發基礎
- 零基礎學Java程序設計
- Expert Data Visualization
- Visual C#通用范例開發金典
- AIRIOT物聯網平臺開發框架應用與實戰
- The Professional ScrumMaster’s Handbook
- Modern C++ Programming Cookbook
- Cocos2d-x Game Development Blueprints
- MySQL程序員面試筆試寶典
- 創意UI：Photoshop玩轉APP設計
- OpenCV with Python Blueprints