Issues and solutions for iOS writing projects (2)

11. Adaptive Text Height

1 nsdictionary *attributes = @{nsfontattributename: [uifont systemfontofsize:]}; 2 3 CGRect rect = [Text Boundingrectwithsize:cgsizemake (Viewwidth, maxfloat) options: Nsstringdrawinguseslinefragmentorigin attributes:attributes  Context:nil]; 4 5 return rect.size.height;

IOS9 Adaptation Settings

In fact, in Xcode 7, when we create a new iOS program, the Bitcode option is set to Yes by default. We can see this setting in the "Build Settings", "Enable bitcode" option.

Either let the third-party library support or turn off the target's bitcode option.

IOS9 HTTPS to HTTP

1 <key>NSAppTransportSecurity</key> 2  3     <dict> 4  5          <!--Connect to anything ( This was probably bad)-- 6  7         < Key>nsallowsarbitraryloads</key> 8  9         <true/>  One     </dict>

14. Intercepting strings

[Str substringfromindex:6];

Substringwithrange:nsmakerange (4,2) intercepts a portion of a string, starting with the 4th bit, intercepting two-bit

substringtoindex:n Intercept to the first few

The (substringfromindex:n) string is intercepted from the nth bit until the last

16.nsscanner:nil string argument

The reason for the error is that when we call a method, we pass in an empty string (note that the string content is empty) as a method parameter.

I get a string of data from the server, considering that some objects do not contain this string variable, I use the first to determine whether the string is empty, for example:

Suppose that this string is called STR,

First determine if (Str!=nil) {

Do something

Double Data=[str Doublevalue];

}

However, when the data is empty, the error is still

The official Apple document has such a code:

1. ID avalue = [arraywithnull objectatindex:0];
2. if (Avalue = = nil) {
3. NSLog (@ "equals nil");
4. } else if (avalue = = [NSNull null]) {
5. NSLog (@ "equals NSNull instance");
6. if ([Avalue Isequal:nil]) {
7. NSLog (@ "Isequal:nil");
8. }
9. }
10. Output: "Equals NSNull instance"

Although finally my problem solved, I in the If Judgment with

1. if (![ Tmpnewsmodel.latitude isequal:[nsnull Null]]) {
2. Do something
3. }

The problem is solved, but not quite understand the difference between nil and nsnull?

17.iphone size

18. Modify the Mac host file

sudo nano/etc/hosts

The same is the input password, open the Hosts file, according to your needs to edit the file, after editing, press Ctrl+o Save,

When the File Name to Write:/etc/hosts, press ENTER to confirm, and then press Ctrl+x to exit.

IOS8 set TableView Separatorinset Split line start from the top of the border

The following methods have been tested to work correctly on iOS7 8

1-(void) Viewdidlayoutsubviews2 3 {4 5     if([Self.tableview respondstoselector: @selector (setseparatorinset:)]) {6 7[Self.tableview Setseparatorinset:uiedgeinsetsmake (0,0,0,0)];8 9     }Ten  One      A  -     if([Self.tableview respondstoselector: @selector (setlayoutmargins:)]) { -  the[Self.tableview Setlayoutmargins:uiedgeinsetsmake (0,0,0,0)]; -  -     } -  + } -  +   A  at-(void) TableView: (UITableView *) TableView Willdisplaycell: (UITableViewCell *) cell Forrowatindexpath: (Nsindexpath *) Indexpath -  - { -  -     if([Cell Respondstoselector: @selector (setseparatorinset:)]) { -  in [Cell Setseparatorinset:uiedgeinsetszero]; -  to     } +  -      the  *     if([Cell Respondstoselector: @selector (setlayoutmargins:)]) { $ Panax Notoginseng [Cell Setlayoutmargins:uiedgeinsetszero]; -  the     } +  A}

20.url can not have Chinese characters, need to convert no will request error

Issues and solutions for iOS writing projects (2)