IOS UI Basics 01

<span id="Label3"></p> <ul> <li><li><p>Controller</p> <ul> <li>1. What is a controller: any class that inherits from Uiviewcontroller is called a controller</li> <li>2. The role of the Controller: manage UI interface (responsible for managing UI interface creation and handling of some events)</li> </ul></li></li> <li><li><p>Ibaction</p> <ul> <li>Connection method <ul> <li>1. Connect to "Storyboard" from "controller"</li> <li>2. Connect from "Storyboard" to "controller"</li> <li>3. Connect directly to the top of the interface on "Storyboard" in "Storyboard"</li> <li>4. Directly in the "Storyboard" to the "Storyboard" on the tool bar connection</li> <li>5. Do not define the method first, directly from "Storyboard" to "controller" connection</li> </ul></li> <li>Attention Points of Ibaction connection <ul> <li>1. Be careful when copying elements in storyboard</li> <li>2. The copy will be copied together with the previous Connection.</li> <li>3. A method can be associated with a number of controls</li> <li>4. A control can be wired in a variety of ways in development, usually not written like this</li> <li>5. If you delete the method associated with the button, a classic error will be reported after running reason: '-[viewcontroller redbtnclick]: unrecognized selector sent to instance 0x7fb4aa618e50 '</li> <li>6.IBAction can only be used as the return value of a method ibaction = = Viod</li> </ul></li> </ul></li></li> <li><p><p>UI Control Dimensions</p></p> <ul> <li><li>Most UI controls don't have a default size, so you can't see UIButton</li></li> <li><li>Frame <ul> <li>Frame is 0,0 in the Upper-left corner of the parent control</li> <li><pre><code class="lang-objc"><span class="hljs-built_in">UIButton *btn = [[<span class="hljs-built_in">UIButton alloc] init];btn<span class="hljs-variable">.frame = CGRectMake(<span class="hljs-number">100, <span class="hljs-number">100, <span class="hljs-number">100, <span class="hljs-number">100);</span></span></span></span></span></span></span></code></pre></li> </ul></li></li> <li><li>Bounds <ul> <li>Bounds is in its own upper left corner of 00, so generally set bounds x/y is invalid, the general situation uses bounds to modify the Size.</li> <li><pre><code class="lang-objc"><span class="hljs-built_in">UIButton *btn = [[<span class="hljs-built_in">UIButton alloc] init];btn<span class="hljs-variable">.bounds = CGRectMake(<span class="hljs-number">0, <span class="hljs-number">0, <span class="hljs-number">100, <span class="hljs-number">100);</span></span></span></span></span></span></span></code></pre></li> </ul></li></li> <li><li>Center <ul> <li>The center point is the intersection of the Control's width and height, and half the position of the width</li> <li>Use Center to modify the location in general</li> <li><pre><code class="lang-objc"><span class="hljs-built_in">UIButton *btn = [[<span class="hljs-built_in">UIButton alloc] init];btn<span class="hljs-variable">.center = CGPointMake(<span class="hljs-number">200, <span class="hljs-number">200);</span></span></span></span></span></code></pre></li> </ul></li></li> </ul></li> <li><li>Viewwithtag <ul> <li>Viewwithtag can only find child controls for the current control and the current control, cannot find sibling controls, or the parent control</li> <li>Lookup Order: 1. Find yourself First. 2. Find child controls 3. Find indirect child controls (grandson:)</li> <li>Use tag to get the value of the corresponding tag</li> </ul></li></li> </ul> <ul> <ul> <li>Anonymous categories <ul> <li>The difference between anonymous classification and classification <ul> <li>1. Anonymous classification has no name, category has a name</li> <li>2. Anonymous classification does not need to have the corresponding implementation, but the classification needs to have the corresponding implementation</li> <li>3. Anonymous classifications can declare properties or declare methods, and classifications can only declare methods</li> </ul></li> <li>Watch Out. <ul> <li>Properties and methods that are not exposed to the outside world are unloaded in the anonymous category after development</li> <li>Apple recommends that we write attributes in an anonymous category (extension/class Extensions)</li> </ul></li> </ul></li> </ul> </ul><p><p>IOS UI Basics 01</p></p></span>