1 00:00:00,270 --> 00:00:06,460 Hi everyone in this theater they are really going to go ahead and create another Android application. 2 00:00:06,480 --> 00:00:07,440 So just click on these. 3 00:00:07,500 --> 00:00:13,920 Start in your Android studio project and then for the name of your application just type in here app 4 00:00:14,520 --> 00:00:24,330 or 56 and then click on sit next and here choose AP 16 Android 4.1 Villepin and then click on next and 5 00:00:24,330 --> 00:00:28,510 here choose empty activity next and he can finish. 6 00:00:28,830 --> 00:00:32,550 So now as you can see here our project is actually created. 7 00:00:32,640 --> 00:00:37,560 So let's actually double click on this and this folder here and then click on this lay out the directory 8 00:00:37,650 --> 00:00:41,710 and then DoubleClick and this activity underline made that example here. 9 00:00:41,910 --> 00:00:47,050 So now as you can see here now we want to actually design the user interface of our application so that 10 00:00:47,050 --> 00:00:51,930 naturally select is hell over here and then press on delivery on your keyboard. 11 00:00:51,930 --> 00:00:57,330 So now let's actually drive our linearly vertical into these relatively out here. 12 00:00:57,360 --> 00:01:03,210 So just select is linearly as well as the cut and put it at the center of this relatively out here and 13 00:01:03,210 --> 00:01:08,520 then let's actually drag out a large takes you into these linearly as vertical. 14 00:01:08,520 --> 00:01:15,180 So just select is large the view here and put it at the center of this linearly as vertical and then 15 00:01:15,240 --> 00:01:21,750 double click and it takes you here and then read the text of this takes you and for the ID to step in 16 00:01:21,750 --> 00:01:24,320 here takes the high. 17 00:01:24,590 --> 00:01:25,200 OK. 18 00:01:25,290 --> 00:01:27,920 And then press Enter key on your keyboard. 19 00:01:27,930 --> 00:01:34,200 So now this entry to the right button into this linearly as vertical and put it below these takes you. 20 00:01:34,200 --> 00:01:41,250 And at the center of this nearly 20 COL W any spot in here and for the text just type in here. 21 00:01:41,250 --> 00:01:41,840 Hi. 22 00:01:42,180 --> 00:01:49,060 And for the ID just type in here between high and then press on until key on your keyboard. 23 00:01:49,350 --> 00:01:52,410 So another design about user interface is actually finished. 24 00:01:52,410 --> 00:01:54,850 So let's go back to what main activity that have a file here. 25 00:01:55,080 --> 00:01:58,750 And now let's actually create some objects here. 26 00:01:58,860 --> 00:02:03,780 So the first object that I want to actually declare here is going to be a text view object and the name 27 00:02:03,780 --> 00:02:09,560 of my object is going to be tasty high and then I need to put a semicolon at the end of my statement. 28 00:02:09,930 --> 00:02:14,880 And the second object is going to be of a button and the name of my object is going to be pretty high. 29 00:02:15,090 --> 00:02:17,970 And then I need to put a semi-colon at the end of my statement. 30 00:02:18,000 --> 00:02:19,680 So inside is uncreate Meffert. 31 00:02:19,680 --> 00:02:22,950 Now able want to actually instantiate these two objects. 32 00:02:23,250 --> 00:02:27,620 The first one is going to BTX the high assignment operator. 33 00:02:27,810 --> 00:02:38,040 And then I need to cast this object to a text view object find view by id r r that ID that takes the 34 00:02:38,130 --> 00:02:43,950 high and then I need to put a semicolon at the end of my statement and the second one is going to be 35 00:02:43,950 --> 00:02:46,460 Pythian high assignment operator. 36 00:02:46,710 --> 00:02:55,260 And then I need to cast this object to a button object find view by ID or ID that PTEN ID that pretty 37 00:02:55,450 --> 00:02:56,100 high. 38 00:02:56,310 --> 00:02:59,840 And then I need to put a semicolon at the end of my statement. 39 00:02:59,880 --> 00:03:03,490 So now I want to actually make the spot and a listener to the police of the user. 40 00:03:03,510 --> 00:03:10,620 So here I can just type in between and high that said Uncle listener and that I need to actually pass 41 00:03:10,620 --> 00:03:11,430 the context. 42 00:03:11,430 --> 00:03:16,620 So the context is going through the main activity that this and and here at the top I need to actually 43 00:03:16,620 --> 00:03:21,560 implement so implements on the the view that unclick listener interface. 44 00:03:21,660 --> 00:03:25,430 So if you start unclick listener. 45 00:03:26,230 --> 00:03:32,180 OK so now I need to actually overwrite the and Meffert that is actually inside of this unclick isn't 46 00:03:32,220 --> 00:03:32,930 an interface. 47 00:03:32,940 --> 00:03:38,210 So here I can just point and click and then I need to press press Enter key on my keyboard. 48 00:03:38,340 --> 00:03:41,800 So as you can see here the ankle my foot is actually over right here. 49 00:03:41,940 --> 00:03:45,320 So this actually changed its name to view the arguments name to view. 50 00:03:45,660 --> 00:03:53,410 And now I want to actually put some of the Android lifecycle MFX here and I want to actually show you 51 00:03:53,560 --> 00:03:57,110 a really important point about the Android lifecycle. 52 00:03:57,260 --> 00:03:57,990 OK. 53 00:03:58,290 --> 00:04:03,550 So first of all let's actually create a string value or something valuable insight. 54 00:04:03,570 --> 00:04:04,930 Our main activity class. 55 00:04:05,010 --> 00:04:10,010 So here inside our main activity class here I just need to create a string variable. 56 00:04:10,080 --> 00:04:14,520 So here I just need to refer to the name of this string class and the name of my variable is going to 57 00:04:14,520 --> 00:04:16,180 be strange value. 58 00:04:16,670 --> 00:04:17,210 OK. 59 00:04:17,520 --> 00:04:24,460 And I need to put a semicolon here at the end of my statement and then here are inside our unclick Mefford 60 00:04:24,790 --> 00:04:25,130 here. 61 00:04:25,200 --> 00:04:28,240 I want to actually initialize this variable. 62 00:04:28,590 --> 00:04:31,200 So here I can just type in a string value. 63 00:04:31,350 --> 00:04:35,880 I just need to refer to the name of this rally or with the name of this object as you can see here setting 64 00:04:35,910 --> 00:04:37,380 value assignment operator. 65 00:04:37,560 --> 00:04:41,280 And here I can assign the value high to this body. 66 00:04:41,310 --> 00:04:42,930 Okay to this object. 67 00:04:42,930 --> 00:04:52,960 And now I can just type in here again just typing ATX the high data set text string value. 68 00:04:53,310 --> 00:05:00,180 So now I want to actually assign the value of this string value valuable to this takes the high as you 69 00:05:00,180 --> 00:05:00,820 can see here. 70 00:05:00,960 --> 00:05:06,380 I want to assign the value of the string value variable to listen to this RTX the high stakes the high 71 00:05:06,380 --> 00:05:08,190 that set text string value. 72 00:05:08,190 --> 00:05:10,940 So now let's actually run our project and see what happens. 73 00:05:11,100 --> 00:05:15,520 So here as you can see our application is running on the simulator here. 74 00:05:15,540 --> 00:05:21,480 So if I click on the spot in here lets see what happens soon as I can see we have this value here high. 75 00:05:21,600 --> 00:05:23,190 Ok for the state's view. 76 00:05:23,190 --> 00:05:26,290 So this actually rotate the device and see what happens. 77 00:05:26,400 --> 00:05:28,810 So just click on this rotate right here. 78 00:05:29,830 --> 00:05:32,280 And now as you can see this value is gone. 79 00:05:32,430 --> 00:05:32,810 OK. 80 00:05:32,890 --> 00:05:34,170 So what's going on here. 81 00:05:34,330 --> 00:05:41,050 So we have a very big problem here vended device is actually rotated on many devices actually in the 82 00:05:41,770 --> 00:05:43,100 landscape mode. 83 00:05:43,270 --> 00:05:43,930 OK. 84 00:05:43,960 --> 00:05:46,280 The Andi's treatment for it is going to be called. 85 00:05:46,300 --> 00:05:50,930 So for example now as you can see the device is actually in the portrait mode right. 86 00:05:51,100 --> 00:05:55,350 And now I want to actually see my application in the landscape. 87 00:05:55,390 --> 00:05:58,330 So if I click on this rotate right button here. 88 00:05:58,330 --> 00:06:01,620 Now my application is actually in the landscape mode. 89 00:06:01,810 --> 00:06:09,910 And when the device is going to actually change its orientation or for example from vertical to horizontal 90 00:06:09,910 --> 00:06:15,330 or from horizontal to vertical the undestroyed Murphy is going to be called and undestroyed move it 91 00:06:15,340 --> 00:06:18,330 is going to be called the application is going to be destroyed. 92 00:06:18,540 --> 00:06:18,810 OK. 93 00:06:18,850 --> 00:06:25,870 And that means that we are valuable as the value of our valuables are going to be actually empty and 94 00:06:25,900 --> 00:06:30,590 we can see that we cannot see now the value of this takes here. 95 00:06:30,610 --> 00:06:36,480 So if I click on this high button here again and and if I actually change the orientation of this device 96 00:06:36,490 --> 00:06:39,900 now by clicking on this rotate left here. 97 00:06:39,910 --> 00:06:43,580 Now as you can see the value of these tapes is gone. 98 00:06:43,630 --> 00:06:45,670 So we need to save this value. 99 00:06:45,670 --> 00:06:50,940 The value of that takes you up before the app the application is actually completely destroyed. 100 00:06:51,100 --> 00:06:57,930 So let me actually paste in some other Android lifecycle if it's here and then it'll make sense to you. 101 00:06:57,940 --> 00:07:03,640 So now after the creation of this article each method here as you can see inside this main activity 102 00:07:03,640 --> 00:07:09,430 class I'm going to paste in some lines of code here and then I'm going to explain to you what's going 103 00:07:09,430 --> 00:07:10,740 on here. 104 00:07:10,780 --> 00:07:16,040 So as you can see here these are the lines of code that are actually pasted here. 105 00:07:16,060 --> 00:07:16,540 OK. 106 00:07:16,720 --> 00:07:19,540 So first of all let me explain to you what's going on here. 107 00:07:19,720 --> 00:07:23,530 So I ask here first about I actually place that this method here. 108 00:07:23,590 --> 00:07:28,130 So the access modifier of this method is public. 109 00:07:28,360 --> 00:07:33,650 The return type of this method is void and the name of this method is let's create a toast. 110 00:07:33,760 --> 00:07:34,260 OK. 111 00:07:34,480 --> 00:07:39,460 So the job of this method is to actually create a toast and a short that goes to the user. 112 00:07:39,460 --> 00:07:45,720 And this method actually accepts an argument of type strange and the name of this argument is message. 113 00:07:45,760 --> 00:07:46,230 OK. 114 00:07:46,390 --> 00:07:52,090 So inside this method as you can see inside the curly braces of this method I actually created a host 115 00:07:52,090 --> 00:07:52,600 object. 116 00:07:52,660 --> 00:07:56,940 So you referred to the name of this TOSed class that makes text. 117 00:07:57,070 --> 00:08:02,560 First of all I actually passed the context main activity that this the second argument is going to be 118 00:08:02,560 --> 00:08:04,880 the message that I want to show to the user. 119 00:08:04,960 --> 00:08:10,120 So the message is going to be the argument that it's going to be passed to dismiss it. 120 00:08:10,120 --> 00:08:15,610 Let's create a toast and a fresh argument is going to be and the failed argument is going to be the 121 00:08:15,610 --> 00:08:18,480 length that is going to be shown to the user. 122 00:08:18,640 --> 00:08:23,230 And finally what I'm actually calling this show Mefford on this object. 123 00:08:23,290 --> 00:08:23,530 OK. 124 00:08:23,530 --> 00:08:26,590 So that this toast is going to be shown to the user. 125 00:08:26,620 --> 00:08:30,110 So as you can see here these are the Android lifecycle methods. 126 00:08:30,130 --> 00:08:34,780 For example the uncreate Mefford is actually an android lifecycle Meffert. 127 00:08:34,780 --> 00:08:40,720 So let's actually create a toast inside this uncreate Meffert in order to let the user know when the 128 00:08:40,720 --> 00:08:42,350 uncreate if it is actually called. 129 00:08:42,400 --> 00:08:45,950 Ok so here I can just refer to that to the name of this. 130 00:08:46,080 --> 00:08:47,520 Let's create a two Smurfette. 131 00:08:47,540 --> 00:08:49,570 Inside these uncreate method. 132 00:08:49,690 --> 00:08:57,550 So let's create a toast and for the message I need to pass the message that I want to show to the user 133 00:08:57,820 --> 00:09:12,570 so I can just type in the on create the create method is called Ok it's called. 134 00:09:12,880 --> 00:09:15,330 So I just put this Meffert here. 135 00:09:15,340 --> 00:09:20,410 Let's create a toast and then I actually put this message in order to show to the user that the uncreate 136 00:09:20,420 --> 00:09:23,380 method is actually called Inside this uncreate method. 137 00:09:23,500 --> 00:09:28,380 And the next Android lifecycle Meffert is actually the Smurfette on start Moffet. 138 00:09:28,380 --> 00:09:30,820 So after this method here let's create a toss. 139 00:09:30,970 --> 00:09:33,990 I actually pasted this method here on a start. 140 00:09:34,000 --> 00:09:37,290 So as you can see here the axis modifier of this method is protected. 141 00:09:37,450 --> 00:09:42,910 OK so you are actually inheriting this Smurfette from the superclass which is activity and as you can 142 00:09:42,910 --> 00:09:44,610 see here we are all writing this class. 143 00:09:44,620 --> 00:09:45,060 OK. 144 00:09:45,220 --> 00:09:50,920 So the return type of the Smurfette is void and the name of this is unstuffed so honest thought Meffert 145 00:09:50,920 --> 00:09:55,190 is going to be called after the uncreate method as you can see here. 146 00:09:55,210 --> 00:10:00,700 So inside this unstarted effort as you can see first that what I am actually calling the super version 147 00:10:00,700 --> 00:10:07,060 of the Smurfette Superlight on a slot and then in line 53 I am actually creating a tossed object in 148 00:10:07,060 --> 00:10:12,850 order to show to the user that that Vendy unstarted if it is going to be called an honest start. 149 00:10:12,850 --> 00:10:20,190 If it is going to be called after the uncreate Smurfit so after the unstarted if it is called the on 150 00:10:20,230 --> 00:10:25,900 resume if it is going to be called ok as you can see here again we are inheriting this Merfeld from 151 00:10:25,900 --> 00:10:33,160 the activity class and here as you can see in line fifty fifty eight you are actually calling the supervision 152 00:10:33,370 --> 00:10:39,010 of the Smurfette superdad and raising of my fifth and in line 60 you are actually creating an object 153 00:10:39,210 --> 00:10:42,440 or a host object in order to show to the user. 154 00:10:42,460 --> 00:10:46,770 So let's create a toast and resume if it is called as you can see here. 155 00:10:47,170 --> 00:10:51,100 And then as you can see here on here we have these on plasma. 156 00:10:51,280 --> 00:10:57,340 So if the user clicks that clicks on the back button on the device or if the user for example switches 157 00:10:57,340 --> 00:11:02,680 between the applications the unpeeled the unplausible if it is going to be called as you can see here. 158 00:11:02,680 --> 00:11:07,420 So as you can see here again we are actually creating a host object in order to let the user know when 159 00:11:07,420 --> 00:11:09,340 they are unpause if it is called. 160 00:11:09,850 --> 00:11:12,350 And as you can see here we have this unstopped Meffert. 161 00:11:12,580 --> 00:11:17,890 So after the unpause Mefford for example when the user clicks on the back button on the device at the 162 00:11:17,980 --> 00:11:20,090 first level the positive it is going to be called. 163 00:11:20,140 --> 00:11:22,740 And then the unstopped if it is going to be called. 164 00:11:22,810 --> 00:11:27,990 Ok so here we are actually creating a tossed object in order to show to the user this message. 165 00:11:28,150 --> 00:11:31,750 Honestly if it is called and then we have these on these three MF'er. 166 00:11:31,750 --> 00:11:38,620 So this is going to be called of any application is actually destroyed from the memory and the information 167 00:11:38,950 --> 00:11:41,690 inside the application is actually completely gone. 168 00:11:41,860 --> 00:11:46,810 So as you can see I am actually creating a host object in order to let the user know that Vendy on the 169 00:11:46,810 --> 00:11:50,790 stream if it is called and here we have two new methods. 170 00:11:50,900 --> 00:11:57,390 OK you already saw these methods in the previous tutorials and actually talked about Android lifecycle 171 00:11:57,400 --> 00:11:57,960 methods. 172 00:11:58,090 --> 00:12:03,430 But these two methods are actually two new methods that of the Android lifecycle that I want to talk 173 00:12:03,430 --> 00:12:04,660 about in this tutorial.