Android Development Engineer Anthology-related controls explained, five layouts

Objective

Hello everyone, to bring you Android开发工程师文集-相关控件的讲解，五大布局 an overview, I hope you like

TextView controls

What are the properties of the TextView control:

android:id->控件的idandroid:layout_width->控件的宽度android:layout_height->控件的高度android:text->文本内容android:textSize->文本的大小android:textColor->文本的颜色android:background->控件的背景，可设置颜色或图片

EditText controls

What are the properties of the EditText control:

android:id->android:layout_width:android:layout_height:android:text:android:textSize:android:textColor:android:background://android:hint->输入提示android:inputType->输入的类型

Set color

1. In XML, it's Android:textcolor.
2. It's settextcolor in the activity.

Autocompletetextview

Autocompletetextview the prompt message that appears when you enter text automatically for the control.
Related properties:android:completionThreshold="2"

Example code:

private String[] strings={ "数据1","数据2",....};//初始化控件//需要适配器//初始化数据源//adpter-autocompleteTextViewautocompleteTextView = findViewById(R.id.autocompleteTextView);ArrayAdapter<String> adapter=new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,strings);autocompleteTextView.setAdapter(adapter);

Multiautocompletetextview

The main thing is that you can select multiple values.
Here the main delimiter, you can enter multiple values

multiAutoCompleteTextView = findViewById(R.id.multiAutoCompleteTextView);multiAutoCompleteTextView.setAdapter(adapter);

Note To set the delimiter

multiAutoCompleteTextView.setTokenizer(new multiAutoCompleteTextView.CommaTokenizer());

ToggleButton

This ToggleButton has two states, one is selected and one is not selected.

Can be understood as the switch effect of the electric light, the property is:

android:checked="true"android:textOff="off"android:textOn="on"

The main methods of implementation:

@Overridepublic void onCheckedChanged(CompoundButton, buttonView, boolean isChecked){ //图片的切换 imgpicture.setBackgroundResource(isChecked?R.drawable.one:R.drawable.two);}

Intent jump

1. startActivity(intent);2. startActivityForResult(intent,requestCode);onActivityResult();//MainActivityonResult();

Next only Learn Startactivityforresult ():

Intent intent = new Intent(MainActivity.this,SecondActivity.class);startActivityForResult(intent,1);

Create the Onactivityresult () method with the mainactivity:
Receive the returned data

@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data){ super.onActivityResult(requestCode, resultCode, data);}

So the method of creating Onresult () in secondactivity:
Callback Intent object, return data

Intent data=new Intent();data.putExtra("data",name);setResult(2,data);

Onactivityresult () in mainactivity:

@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data){ super.onActivityResult(requestCode, resultCode, data);  if(requestCode == 1 && resultCode == 2){  String name = data.getStringExtra("data");  tv.setText(name);}

Four components

Four components of Android

• Activity
• Service
• Broadcastreceiver
• Content Provider

Learn the life cycle of activity again

• OnCreate ();
• OnStart ();
• Onresume ();
• OnPause ();
• OnStop ();
• OnDestroy ();
• Onrestart ();

Four states of activity:

1. Activity status
2. Paused state
3. Stop State
4. Destroy state

A life of activity:

OnCreate ()->onstart ()->onresume ()->onpause ()->onstop ()->ondestroy ()

Start to backstage and then front desk:

OnCreate ()->onstart ()->onresume ()->onpause ()->onstop ()->onrestart ()->onstart ()->onresume ( )

To set the startup mode period for a small window:

Onresume () to get focus
OnPause () to lose focus

OnCreate ()->onstart ()->onresume ()->onpause ()->onresume ()

CheckBox and RadioButton

//核心if(isChecked){ String text = checkBox.getText().toString();}

Here RadioButton, pay attention to radiogroup on the line.

//核心@Overridepublic void onCheckedChanged(RadioGroup group, int checkedId){ switch(checkedId){ case R.id.button1: break; case R.id.button2: break; default: }}

Of course here you can also use RadioButton to monitor, but personally think Radiogroup more convenient!

Five major layouts

LinearLayout:

android:orientation=""1. vertical2. horizontalandroid:gravity=""center,bottom,left,rightandroid:layout_gravity=""android:layout_weight=""//android:layout_height="match_parent"的比例为反，用android:layout_weight=""的话

1. Layout_gravity adjust the position of the layout relative to the parent layout
2. Gravity is where you adjust the layout of the sub-layout
3. Horizontal linearlayout to start from the left to place the layout
   4.layout_gravity only in the LinearLayout layout

Relativelayout:
Relative layout, we just need to know the corresponding property on the line:

android:layout_alignParentLeft="true"android:layout_alignParentTop="true"

android:layout_centerInParent="true"android:layout_centerHorizontal="true"android:layout_centerVertical="true"

android:layout_marginLeft="50dp"android:layout_marginBottom="50dp"

android:layout_toRightOf="@+id/button1"android:layout_toLeftOf="@+id/button2"android:layout_below="@+id/button1"//android:layout_alignBaseline="@+id/button1"

android:gravity=""

These are understood by means of English.

Framelayout:
The first place is below, all in the upper left.

Absolutelayout:

android:layout_x= "50dip"
Android:layout_y= "50dip"

Tablelayout:

Tablerow-view

Important attributes:

//都是从0开始的索引列android:collapseColumns="1,2"//隐藏android:shrinkColumns="1,2"//收缩android:strechColumns="1,2"//拉伸

android:layout_column="1"//显示在第二列android:layout_span="2"//这个表示一个空间占据两列

If you feel good, then you can order a praise!??

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Android Development Engineer Anthology-related controls explained, five layouts