Android自定义组件之自动换行View - 儒雅小生

http://www.tuicool.com/articles/u2eEbe

做Android这么长时间，对自定义组件这块知识了解的很少。之前公司项目里有个模块需求是自动换行，今天重新写个组件实现这个效果。

      效果图如下：

组件是继承的ViewGroup,在用的时候调用addView方法把TextView加进去，然后该组件会把textview放到合适的位置。

WordWrapView.java

public class WordWrapView extends ViewGroup {
private static final int PADDING_HOR = 10;//水平方向padding
private static final int PADDING_VERTICAL = 5;//垂直方向padding
private static final int SIDE_MARGIN = 10;//左右间距
private static final int TEXT_MARGIN = 10;
/**
 * @param context
*/
public WordWrapView(Context context) {
super(context);
}

/**
 * @param context
 * @param attrs
 * @param defStyle
*/
public WordWrapView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}



/**
 * @param context
 * @param attrs
*/
public WordWrapView(Context context, AttributeSet attrs) {
super(context, attrs);
}



@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int childCount = getChildCount();
int autualWidth = r - l;
int x = SIDE_MARGIN;// 横坐标开始
int y = 0;//纵坐标开始
int rows = 1;
for(int i=0;i<childCount;i++){
View view = getChildAt(i);
view.setBackgroundColor(Color.GREEN);
int width = view.getMeasuredWidth();
int height = view.getMeasuredHeight();
x += width+TEXT_MARGIN;
if(x>autualWidth){
x = width+SIDE_MARGIN;
rows++;
}
y = rows*(height+TEXT_MARGIN);
if(i==0){
view.layout(x-width-TEXT_MARGIN, y-height, x-TEXT_MARGIN, y);
}else{
view.layout(x-width, y-height, x, y);
}
}
};

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int x = 0;//横坐标
int y = 0;//纵坐标
int rows = 1;//总行数
int specWidth = MeasureSpec.getSize(widthMeasureSpec);
int actualWidth = specWidth - SIDE_MARGIN * 2;//实际宽度
int childCount = getChildCount();
for(int index = 0;index<childCount;index++){
View child = getChildAt(index);
child.setPadding(PADDING_HOR, PADDING_VERTICAL, PADDING_HOR, PADDING_VERTICAL);
child.measure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);
int width = child.getMeasuredWidth();
int height = child.getMeasuredHeight();
x += width+TEXT_MARGIN;
if(x>actualWidth){//换行
x = width;
rows++;
}
y = rows*(height+TEXT_MARGIN);
}
setMeasuredDimension(actualWidth, y);
}

}

View Code

MainActivity.java

public class MainActivity extends Activity {

private WordWrapView wordWrapView;
private String[] strs = new String[] { "哲学系", "**自治区", "新闻学", "心理学",
"犯罪心理学", "明明白白", "西方文学史", "计算机", "掌声", "心太软", "生命",
"程序开发" };

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
wordWrapView = (WordWrapView) this.findViewById(R.id.view_wordwrap);
for (int i = 0; i < 12; i++) {
TextView textview = new TextView(this);
textview.setText(strs[i]);
wordWrapView.addView(textview);
}
}

}

View Code

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >

<com.winhoo.viewtest.widget.WordWrapView
android:id="@+id/view_wordwrap"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
/>

</RelativeLayout>

activity_main.xml