TextView
1. TextView basic structure + syntax
***textView is a component used by android studio to display strings and text files. It is an area to display a piece of text on a mobile phone***
***textView is an embedded module, some syntax is common***
1. First upload the code and then introduce it one by one
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
%上面布局是相对布局，具体介绍参考上一篇文章
<TextView
android:id="@+id/num_1" %id声明
android:layout_width="match_parent"
android:layout_height="50dp"
android:background="#3399ff"
android:layout_marginTop="10dp"
android:text="baby" %text命令用来书写要显示的内容
android:textColor="#ff0066" %字体颜色
android:textSize="35sp" %字体尺寸
android:gravity="center" %字体布局
/>
</RelativeLayout>
***As shown in the figure, TextView is similar to View, except that the former is a text setting module, and the latter is a view setting module; we write the text baby through the text function, the text color is red, the size is 35sp, and the layout is finalized through gravity central***
***The specific and actual effect needs to be knocked by your own hands, and the result can be referred to***
Button
1. Button basic structure + syntax
***Button is an English word, noun, verb, when used as a noun, it means "button; button, in android studio, is a button component, just like the app in your mobile phone, you can enter it with one click, this mode I will write the settings later, here we first introduce the basic grammar and organization***
1. First upload the code and then introduce them one by one
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
%上面是系统默配置这里不再赘述
<Button %Button声明，里面的好多语法都是通用的
android:id="@+id/btn_1"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_marginTop="10dp"
android:text="hello"
android:textSize="20sp"
android:background="#ff33ff"
android:textColor="#3399ff"
/>
</LinearLayout>
%其实Button只是声明了一个外部结构而已，内部调用的还是我们在TextView和View里面调用的函数，
***As shown in the figure, write a Button component in the xml file, which is only a part. If you want to see the click effect, you must declare it in the corresponding .java and have a corresponding secondary file ***
***Actually, Button, view, and textview are both system components, and you can even just change the name***
TextView+Button constitutes a click component
***We configure a click event below, and the secondary display file is TextView***
1. Configure Button
***Button is in the xml file corresponding to MianActivity***
*** The picture above is the initial file style when creating a new blank document ***
1. First, we create a new Button in activity_main.xml (just copy the code of the Button module above)
*** The picture above is the original code, we can see l*** by opening the location of 1
*** The position shown in 2 above is the code copied from BUtton; note: remove the comment after %; and then see 3 after running ***
2. Next, we find the location of the MianActivity.java file, and create a new java file named textview
*** Find the folder where this file is located **
*** Right click new-->activity-->empty activity, create new **
*** Name it textview, then click finish **
*** The system will automatically generate the corresponding .java file and xml file as shown in Figure 1 and 2 **
*** Then copy the code in the textview above, as shown in Figure 2; **
*** So far, the content of Button and text view has been written, and finally we will call it**
3. Configure the connection between Button and textview
1. Find the MainActivity.Java file and open it
2. According to the 1 2 3 4 shown in the figure below, write the following codes in sequence
1: Declare the BUtton
2: Find the Button (note that btn_1 is the id of the button)
3: Set the click event
4: Set the secondary file after clicking, and start
3. Last point to run
*** The Button style is displayed first. One click **
*** Then enter the secondary file textview **
*** The above is the combined design of Button and textview, for your reference**