Custom ViewGroup controls (i)-----> Flow Layout Advanced (i)

Main.xml

<?xml version= "1.0" encoding= "Utf-8"? ><com.example.simplelayout.mylinlayout xmlns:android= "/http Schemas.android.com/apk/res/android "xmlns:tools=" Http://schemas.android.com/tools "android:layout_width=" Match_ The parent "android:layout_height=" wrap_content "android:background=" #ff00ff "tools:context=".        Mainactivity "> <textview android:layout_width=" wrap_content "android:layout_height=" Wrap_content " android:layout_margintop= "10DP" android:background= "#ff0000" android:text= "First View"/> <text View android:layout_width= "wrap_content" android:layout_height= "Wrap_content" Android:layout_marginto p= "20DP" android:background= "#00ff00" android:text= "Second View"/> <textview android:layout_wid Th= "Wrap_content" android:layout_height= "wrap_content" android:layout_margintop= "30DP" android:backgr Ound= "#0000ff" android:text= "Third View"/></com.example. Simplelayout.mylinlayout>

Mainactivity

Package Com.example.simplelayout;import Android.app.activity;import Android.os.bundle;public class MainActivity Extends Activity {    @Override public    void OnCreate (Bundle savedinstancestate) {        super.oncreate ( Savedinstancestate);        Setcontentview (R.layout.main);    }}

Mylinlayout

Package Com.example.simplelayout;import Android.content.context;import Android.util.attributeset;import Android.view.view;import android.view.viewgroup;/** * onmeasure (): Measure your size, your size, and provide recommendations for the formal layout. (note, just suggest, as to use not, to see OnLayout); * OnLayout (): Use the layout () function to lay out all child controls; OnDraw (): Draw according to the location of the layout; * */public class Mylinlayout extends ViewGroup {/** * First is 3 constructors */p Ublic Mylinlayout (Context context) {super (context);} Public Mylinlayout (context context, AttributeSet Attrs) {Super (context, attrs);} Public Mylinlayout (context context, AttributeSet attrs, int defstyleattr) {Super (context, attrs, defstyleattr);} /** * This viewgroup's wide-height attribute android:layout_width= "match_parent"--exactly (OK) * android:layout_height= "wrap_content"--AT_ Most (indeterminate) * * They are the parent class passed over to the current view of a suggested value, the recommended value, that is, to set the current view size to wide widthmeasurespec, * High Heightmeasurespec * *②, exactly (full), The parent element determines the exact size of the element, and the child element is scoped to the given boundary and ignores its size, *③, At_most (at most), and the child element reaches a value of at most the specified size. */@Overrideprotected void onmeasure (int widthmeasurespec, int heightmeasurespec) {super.onmeasure (Widthmeasurespec, Heightmeasurespec);//width, height int measurewidth = measurespec.getsize (widthmeasurespec); int measureheight = Measurespec.getsize (HEIGHTMEASURESPEC);//measurement mode int measurewidthmode = Measurespec.getmode (widthmeasurespec); int Measureheightmode = Measurespec.getmode (HEIGHTMEASURESPEC);//Initialize viewgroup wide, high int viewgroupheight = 0;int Viewgroupwidth = 0;//gets each child in the ViewGroup view, traversing int count = Getchildcount (), for (int i = 0; i < count; i++) {///Get every Child Sub-View Object View child = Getchildat (i);//measure each child's view and pass the pattern of the parent class into it--point to source Measurechild (child, Widthmeasurespec, HEIGHTMEASURESPEC); int childheight = Child.getmeasuredheight (); int childwidth = Child.getmeasuredwidth ();// ViewGroup height increment viewgroupheight + = childheight;//viewgroup width take maximum viewgroupwidth = Math.max (Childwidth, viewGroupWidth);} The width of the viewgroup does not need to be measured directly "match_parent"--exactly//High is "wrap_content"--at_most, need to accumulate to get the height/** *②, exactly (full), the parent element determines the exact size of the element , the child element is limited to a given boundary and ignores its size, *③, At_most (at most), and the child element reaches a value of at most the specified size. */setmeasureddimension (Measurewidthmode = = Measurespec.exactly)? Measurewidth:viewgroupwidth, (Measureheightmode = = measurespec.exactly)? Measureheight:viewgroupheight);} The/** * Getmeasurewidth () method is available at the end of the measure () process, and the GetWidth () method is not available until the layout () * process is finished. Once again, */@Overrideprotected void OnLayout (Boolean changed, int l, int t, int r, int b) {int top = 0;//Gets the number of child view int count = Getchildcount (); for (int i = 0; i < count; i++) {//Get each child's view object in order, view children = Getchildat (i);//Get the child view's wide-high int CHILDH eight = Child.getmeasuredheight (); int childwidth = Child.getmeasuredwidth (); child.layout (0, Top, childwidth, Top + Childheight);//increment top value of child view top + = Childheight;}}}

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Custom ViewGroup controls (i)-----> Flow Layout Advanced (i)