最近几年来，地理信息系统无论是在理论上还是应用上都处在一个飞速发展的阶段。 GIS被应用于多个领域的建模和决策支持，如城市管理、区划、环境整治等等，地理信息成为信息时代重要的组成部分之一； “数字地球”概念的提出，更进一步推动了作为其技术支撑的GIS的发展。 与此同时，一些学者致力于相关的理论研究，如空间感知、空间数据误差、空间关系的形式化等等。 这恰好说明了地理信息系统作为应用技术和学科的两个方面，并且这两个方面构成了相互促进的发展过程。
We can use the toolbar to modify the view elements.
For example, there are deletions, shares, replies, and so on, in the inbox bar in the mail application. As follows:
Important attribute
BarStyle
Items
9.13.1. Add a custom method addToolbar ¶
-(void)addToolbar { UIBarButtonItem *spaceItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil]; UIBarButtonItem *customItem1 = [[UIBarButtonItem alloc] initWithTitle:@"Tool1" style:UIBarButtonItemStyleBordered target:self action:@selector(toolBarItem1:)]; UIBarButtonItem *customItem2 = [[UIBarButtonItem alloc] initWithTitle:@"Tool2" style:UIBarButtonItemStyleDone target:self action:@selector(toolBarItem2:)]; NSArray *toolbarItems = [NSArray arrayWithObjects: customItem1,spaceItem, customItem2, nil]; UIToolbar *toolbar = [[UIToolbar alloc]initWithFrame: CGRectMake(0, 366+54, 320, 50)]; [toolbar setBarStyle:UIBarStyleBlackOpaque]; [self.view addSubview:toolbar]; [toolbar setItems:toolbarItems]; } To understand what we are doing, we add UILabel Iboutlet to our ViewController.xib and create an IBoutlet named tag for UILabel.
We also need to add two methods to perform the operation of the toolbar item as follows:
-(IBAction)toolBarItem1:(id)sender{ [label setText:@"Tool 1 Selected"]; } -(IBAction)toolBarItem2:(id)sender{ [label setText:@"Tool 2 Selected"]; } Update the viewDidLoad in ViewController.m, as follows:
- (void)viewDidLoad { [super viewDidLoad]; // The method hideStatusbar called after 2 seconds [self addToolbar]; // Do any additional setup after loading the view, typically from a nib. } Output ¶
Now when we run the application, we will see the following output.
Click the tool1 and tool2 bar buttons we got
