Knowledge of IOS nooks and crannies

<span id="Label3"></p><p><p><span style="color: #aa7942;">1. Global Variables</span></p></p><p><p>static Nsinteger Kimageheight = 300;</p></p><p><p>#define Kimageheight 300</p></p><p><p><span style="color: #aa7942;">2. Notification Center</span></p></p><p><p><span style="color: #aa7942;">Start editing</span></p></p><p><p>Uitextviewtextdidbegineditingnotification</p></p><p><p><span style="color: #aa7942;">is changing</span></p></p><p><p>Uitextviewtextdidchangenotification</p></p><p><p><span style="color: #aa7942;">End compilation</span></p></p><p><p>Uitextviewtextdidendeditingnotification</p></p><p><p></p></p><p><p>Registration text Change Notification</p></p><p><p></p></p><p><p>[[nsnotificationcenter defaultcenter] addobserver:self selector: @selector (textdidchangenotifition:) name: Uitextviewtextdidchangenotification object:nil];</p></p><p><p>-(void) Dealloc</p></p><p><p>{</p></p><p><p>[[nsnotificationcenter defaultcenter] removeobserver:self name:uitextviewtextdidchangenotification object:nil];</p></p><p><p></p></p><p><p>}</p></p><p><p></p></p><p><p><span style="color: #aa7942;">3. Dynamic loading (without Importing header files)</span></p></p><p><p><span style="color: #aa7942;"></span></p></p><p><p>Nsarray * vcNames1 = @[@ "friendviewcontroller"];</p></p><p><p>Nsarray * VcNames2 = @[@ "swipeviewcontroller", @ "sharkviewcontroller"];</p></p><p><p></p></p><p><p>Self.viewcontrollers = @[vcnames1,vcnames2];</p></p><p><p>NSString * Vcname = self.viewcontrollers[indexpath.section][indexpath.row];</p></p><p><p></p></p><p><p>Uiviewcontroller * VC = [[nsclassfromstring (vcname) alloc] init];</p></p><p><p>Example: Custom button Class: UIButton</p></p><p><p>The Viewcontroller claims that the corresponding button object is overridden by the Init method to define the type</p></p><p><p>The Button property cannot be written in the Button class because adding a click event to the lazy load cannot be adjusted</p></p><p><p><span style="color: #aa7942;">4. Change the color of the picture; ignore its color information</span></p></p><p><p>Image = [image imagewithrenderingmode:uiimagerenderingmodealwaystemplate];</p></p><p><p></p></p><p><p><span style="color: #aa7942;">5. Project Structure</span></p></p><p><p></p></p><p><p><span style="color: #aa7942;">6, when the Navigation view controller presses the stack, hides the Tabbar</span></p></p><p><p>vc.hidesbottombarwhenpushed = YES;</p></p><p><p><span style="color: #aa7942;">7, Picture and border, code:</span></p></p><pre name="code"><pre name="code">Imagelayer.bordercolor = [uicolor graycolor]. cgcolor; Border color imagelayer.borderwidth = 2.0; Border width</pre></pre><pre name="code"><pre name="code"><span style="color: #aa7942;">8, Lei God teaching block</span></pre></pre><p><p>(1) declaring the block variable and setting the return value type</p></p><p><p>typedef nsstring * (^myblock) (nsstring *);</p></p><p><p>@property (nonatomic, copy) Myblock block;</p></p><p><p>(2) Call the Block method (send) and receive the return value</p></p><p><p>NSString * string = Self.block (@ "123<span style="font-family: Menlo;">"</span>);</p></p><p><p>NSLog (<span style="font-family: Menlo;">@ "%@"</span>, string);</p></p><p><p><span style="font-family: Menlo;">(3)</span> Call The Block method (receive) and receive the return value</p></p><p><p>Self.ceshi.block = ^ (nsstring *string) {</p></p><p><p></p></p><p><p>NSLog (@ "%@", string);</p></p><p><p></p></p><p><p>return<span style="color: #35568a;"><span style="font-family: Menlo;"><span style="font-size: large;">@ "peng"</span></span></span><span style="font-family: Menlo;">;</span></p></p><p><p>};</p></p><p><p>(4) use typedef to define block types (much like pointers to Functions)</p></p><p><p>(class) Typedef int (^myblock) (int, int);</p></p><p><p>You can then use this type to define the block Variable.</p></p><p><p>(class) Myblock block1,block2;</p></p><p><p>(class) int i = Block1 (3,4);</p></p><p><p>(master) block1=^ (int a,int b) {</p></p><p><p>Return a-b;</p></p><p><p>};</p></p><p><p>__weak Viewcontroller *myself = self; Avoid circular references in block</p></p><p><p></p></p><p><p>Knowledge of IOS nooks and crannies</p></p></span>