IOS开发－UI学习－根据URL显示图片，下载图片的练习（button，textfield，image view，url，data）

1    <key>NSAppTransportSecurity</key>
2     <dict>
3     <key>NSAllowsArbitraryLoads</key>
4     <true/>
5     </dict>

  1 #import "ViewController.h"
  2 
  3 @interface ViewController (){
  4 //    定于全局变量
  5     UIButton *btnDownLoad;
  6     UIButton *btndisplay;
  7     UIImageView *imageView;
  8     UITextField *textFieldinputUrl;
  9     NSData *imagedata;
 10     NSString *newpath;
 11     int count;
 12     
 13     
 14 }
 15 
 16 @end
 17 
 18 @implementation ViewController
 19 
 20 - (void)viewDidLoad {
 21     [super viewDidLoad];
 22 
 23     
 24 //    显示图片按钮初始化及加载
 25 //    初始化为圆角矩形按钮
 26     btndisplay = [UIButton buttonWithType:UIButtonTypeRoundedRect];
 27 //    设置按钮的位置，大小
 28     btndisplay.frame = CGRectMake(100, 660, 100 ,50 );
 29 //    设置按钮背景色
 30     btndisplay.backgroundColor = [UIColor colorWithRed:0.512 green:0.562 blue:0.943 alpha:1.000];
 31 //    设置按钮文本颜色及文本内容
 32     [btndisplay setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
 33     [btndisplay setTitle:@"显示图片" forState:UIControlStateNormal] ;
 34 //    给按钮添加显示图片事件
 35      [btndisplay addTarget:self action:@selector(display:) forControlEvents:UIControlEventTouchUpInside];
 36 //    把按钮加载到view上
 37     [self.view addSubview:btndisplay];
 38     
 39 //   下载图片按钮初始化及加载
 40     btnDownLoad = [[UIButton alloc]initWithFrame:CGRectMake(218, 660, 100, 50)];
 41     btnDownLoad.backgroundColor = [UIColor colorWithRed:0.512 green:0.562 blue:0.943 alpha:1.000];
 42     [btnDownLoad setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
 43     [btnDownLoad setTitle:@"下载图片" forState:UIControlStateNormal] ;
 44     [btnDownLoad addTarget:self action:@selector(download:) forControlEvents:UIControlEventTouchUpInside];
 45     [self.view addSubview:btnDownLoad];
 46     
 47 //    设置URL输入框
 48 //    初始化文本输入框及背景色设置
 49     textFieldinputUrl = [[UITextField alloc]initWithFrame:CGRectMake(20, 590, 378, 50)];
 50     textFieldinputUrl.backgroundColor = [UIColor colorWithRed:0.653 green:1.000 blue:0.919 alpha:1.000];
 51 //    设置文本输入前提示水印
 52     textFieldinputUrl.placeholder = @"请输入图片地址";
 53 //    设置文本输入框中消除按钮
 54     textFieldinputUrl.clearButtonMode = UITextFieldViewModeAlways;
 55 //    把文本输入框加载到View
 56     [self.view addSubview:textFieldinputUrl];
 57     
 58     
 59 //    设置图片控件
 60     imageView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 20, 418, 550)];
 61     imageView.backgroundColor = [UIColor grayColor];
 62     [self.view addSubview:imageView];
 63     
 64 //    获取沙盒中document的路径
 65     NSString *dictpath = [NSString stringWithFormat:@"%@/Documents",NSHomeDirectory()];
 66 //    创造一个字符串指向document中的要新建的download文件夹
 67     newpath =[NSString stringWithFormat:@"%@/download",dictpath];
 68 //    在document中新建download文件夹
 69     [[NSFileManager defaultManager]createDirectoryAtPath:newpath withIntermediateDirectories:YES attributes:nil error:nil];
 70     
 71     NSLog(@"%@",dictpath);
 72 }
 73 
 74 
 75 //显示图片
 76 -(void)display:(id)sender{
 77     
 78 //    把文本框输入的URL转换成数据
 79     NSURL *imageurl = [NSURL URLWithString:textFieldinputUrl.text];
 80     imagedata = [NSData dataWithContentsOfURL:imageurl];
 81 //    把数据转换成图片
 82     UIImage *image = [UIImage imageWithData:imagedata];
 83 //    转换的图片给UIImageView显示
 84     imageView.image =image;
 85     
 86 }
 87 
 88 
 89 //下载图片
 90 -(void)download:(id)sender{
 91     count++;
 92 //    在路径下新建图片文件
 93     NSString *newfilepath = [NSString stringWithFormat:@"%@/%d.jpg",newpath,count];
 94 //    把图片数据保存在路径下新建好的文件中
 95     [[NSFileManager defaultManager]createFileAtPath:newfilepath contents:imagedata attributes:nil];
 96 }
 97 
 98 
 99 //输入结束后让键盘滚蛋
100 -(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
101     [textFieldinputUrl resignFirstResponder];
102 }
103 
104 
105 
106 - (void)didReceiveMemoryWarning {
107     [super didReceiveMemoryWarning];
108     // Dispose of any resources that can be recreated.
109 }
110 
111 @end

1 //输入结束后让键盘滚蛋
2 -(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
3     [textFieldinputUrl resignFirstResponder];
4 }

1 //下载图片
2 -(void)download:(id)sender{
3    count++;
4 //   在路径下新建图片文件
5   看集  NSString *newfilepath = [NSString stringWithFormat:@"%@/%d.jpg",newpath,count];
6 //    把图片数据保存在路径下新建好的文件中
7     [[NSFileManager defaultManager]createFileAtPath:newfilepath contents:imagedata attributes:nil];
8 }