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自定义ViewGroup实现view的自由布局

2016年08月13日 Android ⁄ 共 4375字 ⁄ 字号 自定义ViewGroup实现view的自由布局已关闭评论 ⁄ 阅读 741 次

前段时间有个需求是:

  1. 给定一个list 数组,根据集合里面的数据来画View;
  2. View的数目是小于等于手机横屏后的宽度。

传统的线性布局,相对布局都不能满足这个需求,所以我们只能自己来自定义一个ViewGroupl 。

自定义ViewGroup

我们知道ViewGroup就是View的容器类,我们经常用的LinearLayout,RelativeLayout等都是ViewGroup的子类。

CustomViewGroup.java

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public class CustomViewGroup extends ViewGroup {

private final static String TAG = "CustomViewGroup";

// view 的间隔
private final static int VIEW_MARGIN = 0;

public CustomViewGroup(Context context) {
super(context);
}

// 重写它的onMeasure() 在该方法中进行对子View的大小进行测量
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

Log.d(TAG, "widthMeasureSpec = " + widthMeasureSpec
+ " heightMeasureSpec" + heightMeasureSpec);
for (int index = 0; index < getChildCount(); index++) {
final View child = getChildAt(index);
child.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

// 重写onLayout方法实现子View的定位
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {

Log.d(TAG, "changed = " + changed + " left = " + l + " top = " + t
+ " right = " + r + " botom = " + b);
final int count = getChildCount();
int row = 0;
//当前宽度
int lengthX = l;
//当前高度
int lengthY = t;
for (int i = 0; i < count; i++) {
final View child = this.getChildAt(i);
int width = child.getMeasuredWidth();
int height = child.getMeasuredHeight();
lengthX += width + VIEW_MARGIN;
lengthY = row * (height + VIEW_MARGIN) + VIEW_MARGIN + height
+ t;
if (lengthX > r) {
lengthX = width + VIEW_MARGIN + l;
row++;
lengthY = row * (height + VIEW_MARGIN) + VIEW_MARGIN + height
+ t;
}
child.layout(lengthX - width, lengthY - height, lengthX, lengthY);
}
}
}

MainActivity.java

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public class MainActivity extends Activity {
private CustomViewGroup mViewGroup;
private ArrayList<ViewSizeInfo> mViewSizes;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

//初始化数据
mViewSizes = getViewSizes();
mViewGroup = getViewGroup(mViewSizes);
setContentView(mViewGroup);
}

private ArrayList<ViewSizeInfo> getViewSizes() {
ArrayList<ViewSizeInfo> viewSizes = new ArrayList<>();

viewSizes.add(new ViewSizeInfo(1, 1,R.color.colorAccent));
viewSizes.add(new ViewSizeInfo(3, 2,R.color.colorDarkOrchid));
viewSizes.add(new ViewSizeInfo(4, 4,R.color.colorPrimary));
viewSizes.add(new ViewSizeInfo(1, 5,R.color.colorLightBLue));
return viewSizes;
}

private CustomViewGroup getViewGroup(ArrayList<ViewSizeInfo> viewSizes) {
CustomViewGroup myViewGroup = new CustomViewGroup(this);

myViewGroup.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
int width = ScreenUtil.getScreenWidth(this)/10;
int height =ScreenUtil.getScreenHeight(this)/5;

for (int i = 0; i <viewSizes.size() ; i++) {
ViewSizeInfo viewSize =viewSizes.get(i);
TextView textView = new TextView(this);
textView.setText("TextView"+i);
textView.setBackgroundColor(getResources().getColor(viewSize.getColor()));
textView.setWidth(width* viewSize.getWidth());
textView.setHeight(height* viewSize.getHeight());
myViewGroup.addView(textView);
}
return myViewGroup;
}
}

ViewSizeInfo.java

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public class ViewSizeInfo {
private int mWidth;
private int mHeight;
// 设置默认颜色
private int color;

public ViewSizeInfo(int width, int height) {
this.mWidth = width;
this.mHeight = height;
}

public ViewSizeInfo(int width, int height, int color) {
this.mWidth = width;
this.mHeight = height;
this.color = color;
}

public int getWidth() {
return mWidth;
}

public void setWidth(int width) {
this.mWidth = width;
}

public int getHeight() {
return mHeight;
}

public void setHeight(int height) {
this.mHeight = height;
}

public int getColor() {
return color;
}

public void setColor(int color) {
this.color = color;
}
}

ScreenUtil.java

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public class ScreenUtil {
private ScreenUtil() {
/*cannot be instantiated*/
throw new UnsupportedOperationException("cannot be instantiated");
}

/**
* 获得屏幕宽度
*
* @param context
* @return
*/
public static int getScreenWidth(Context context) {
WindowManager wm = (WindowManager) context
.getSystemService(Context.WINDOW_SERVICE);
DisplayMetrics outMetrics = new DisplayMetrics();
wm.getDefaultDisplay().getMetrics(outMetrics);
return outMetrics.widthPixels;
}

/**
* 获得屏幕高度
*
* @param context
* @return
*/
public static int getScreenHeight(Context context) {
WindowManager wm = (WindowManager) context
.getSystemService(Context.WINDOW_SERVICE);
DisplayMetrics outMetrics = new DisplayMetrics();
wm.getDefaultDisplay().getMetrics(outMetrics);
return outMetrics.heightPixels;
}
}

效果图

自定义ViewGroup实现view的自由布局

完整代码已经上传到Github了:https://github.com/HJXANDHMR/CustomViewGroup

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