Android 自定义GridLayout实现频道管理

前言

以前总是在CSDN上看各位前辈的精彩博客，从中也学习了很多东西。其实自己也一直想写博客，直到今天终于要踏出这一步了，有点小兴奋，哈哈！不足之处，还请各位同仁不吝赐教，拜谢！！！

话不多说，工作中我们时常会遇到频道管理的需求，不少博客使用GridView实现这一功能，个人喜欢用自定义的GridLayout实现，萝卜白菜各有所爱，嘿嘿。

功能





要实现的功能如上图所示（当然，左边只是一个参考，这里界面不是重点，我们要实现这个功能）

1.   分上下两部分

2.“我的频道”实现了长按拖拽排序功能；同时，点击某一子条目时，将该条目从“我的频道”中删除，添加到“更多频道”中。

3.“更多频道”实现了点击事件，当点击某一子条目时，该子条目从“更多频道”中删除，添加到“我的频道”中。

实现代码

主程序代码：

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

private DragGridLayout showGridLayout;
private DragGridLayout hideGridLayout;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initCustom();
}

private void initCustom() {
showGridLayout = (DragGridLayout) findViewById(R.id.dgl_main_show);
showGridLayout.setResource(R.drawable.selector_textbg, 10, 5);
showGridLayout.setEnableDrag(true);
List<String> items = new ArrayList<>();
items.add("推荐");
items.add("本地事");
items.add("本地人");
items.add("社区");
items.add("图集");
items.add("要闻");
items.add("热点");
items.add("旅游");
items.add("健康");
showGridLayout.setItems(items);
hideGridLayout = (DragGridLayout) findViewById(R.id.dgl_main_bottom);
hideGridLayout.setEnableDrag(false);
hideGridLayout.setResource(R.drawable.selector_textbg,
b871
10, 5);
List<String> items1 = new ArrayList<>();
items1.add("家居");
items1.add("奇石");
items1.add("螺蛳粉");
items1.add("情感");
items1.add("文化");
items1.add("体育");
items1.add("汽车");
items1.add("本地号");
items1.add("爆料");
items1.add("时政");
items1.add("美女");
items1.add("公益");
items1.add("公民榜样");
items1.add("亲子");
items1.add("社会");
items1.add("舌尖柳州");
items1.add("开心一刻");
items1.add("居柳州");
hideGridLayout.setItems(items1);

//设置点击事件
showGridLayout.setOnItemClickListener(new DragGridLayout.OnItemClickListener() {
@Override
public void onItemClick(TextView tv) {
//当点击时，将返回的TextView从showGridLayout容器中删除，在添加到hideGridLayout中
showGridLayout.removeView(tv);
hideGridLayout.addItem(tv.getText().toString());
}
});

hideGridLayout.setOnItemClickListener(new DragGridLayout.OnItemClickListener() {
@Override
public void onItemClick(TextView tv) {
hideGridLayout.removeView(tv);
showGridLayout.addItem(tv.getText().toString());
}
});

}

}

布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
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"
android:orientation="vertical">

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/colorPry"
android:text="点击增删频道，长按拖拽排序"/>

<com.example.customview.DragGridLayout
android:id="@+id/dgl_main_show"
android:layout_width="match_parent"
android:layout_height="wrap_content">

</com.example.customview.DragGridLayout>

</LinearLayout>

<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">

<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/colorPry"
android:text="频道管理"/>

<com.example.customview.DragGridLayout
android:id="@+id/dgl_main_bottom"
android:layout_width="match_parent"
android:layout_height="wrap_content">

</com.example.customview.DragGridLayout>

</LinearLayout>

</LinearLayout>

自定义GridLayout：

注释比较详细了，直接上代码，其中的一些参数，例如margin和padding，可根据项目需求，具体定制。

import android.animation.LayoutTransition;
import android.content.Context;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.DragEvent;
import android.view.Gravity;
import android.view.View;
import android.widget.GridLayout;
import android.widget.TextView;

import java.util.List;

/**
* Created by ZLM on 2017/4/3.
*/

public class DragGridLayout extends GridLayout {

private boolean ableDrag;
private Rect[] rects;
private View dragView;
private OnItemClickListener itemClickListener;

//拖拽监听
private View.OnDragListener odl = new View.OnDragListener() {
@Override
public boolean onDrag(View view, DragEvent dragEvent) {
switch (dragEvent.getAction()) {
case DragEvent.ACTION_DRAG_STARTED:
//当拖拽事件产生时，给每个子控件创建出对应的矩形
initRects();
break;
case DragEvent.ACTION_DRAG_LOCATION:
//当手指移动时，判断当前进入了哪一个子控件范围内，并返回对应子控件的索引
int touchIndex = getTouchIndex(dragEvent);
if (touchIndex > -1 && dragView != null && dragView != DragGridLayout.this.getChildAt(touchIndex)) {
//先把拖拽的view从当前位置删除，再添加到touchIndex上
DragGridLayout.this.removeView(dragView);
DragGridLayout.this.addView(dragView, touchIndex);
}
break;
case DragEvent.ACTION_DRAG_ENDED:
if (dragView != null) {
dragView.setEnabled(true);
}
break;
default:
break;
}
return true;
}
};
//长按监听
private View.OnLongClickListener olcl = new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
//长按事件发生时，即给dragView赋值
dragView = view;
//拖拽事件
view.startDrag(null, new View.DragShadowBuilder(view), null, 0);
view.setEnabled(false);
return false;
}
};

private int getTouchIndex(DragEvent dragEvent) {
for (int i = 0; i < rects.length; i++) {
Rect rect = rects[i];
if (rect.contains((int) dragEvent.getX(), (int) dragEvent.getY())) {
return i;
}
}
return -1;
}

//创建子控件对应的矩形
private void initRects() {
//给容器中的每一个子控件都新建一个矩形
rects = new Rect[getChildCount()];
for (int i = 0; i < getChildCount(); i++) {
View childAt = getChildAt(i);
rects[i] = new Rect(childAt.getLeft(), childAt.getTop(), childAt.getRight(), childAt.getBottom());
}
}

public DragGridLayout(Context context) {
this(context, null);
}

public DragGridLayout(Context context, AttributeSet attrs) {
super(context, attrs);
setColumnCount(4);
setLayoutTransition(new LayoutTransition());
}

//定义方法，由外部传递一个栏目的数据集合进来，在这里根据数据集合动态创建表格界面
public void setItems(List<String> items) {
for (String item : items) {
addItem(item);
}
}

//定义方法，设置是否允许拖拽
public void setEnableDrag(boolean EnableDrag) {
ableDrag = EnableDrag;
if (ableDrag) {
setOnDragListener(odl);
} else {
setOnDragListener(null);
}
}

//定义接口回调
public interface OnItemClickListener {
public void onItemClick(TextView tv);
}

public void setOnItemClickListener(OnItemClickListener listener) {
this.itemClickListener = listener;
}

public void addItem(String item) {
TextView tv = getNewTextView();
tv.setText(item);
this.addView(tv);
}

//定义方法，外部传入子条目的背景资源Id,外边距margin（px）,tv内边距padding（px）
private final float scale = getContext().getResources().getDisplayMetrics().density;
private int resId;
private int margin;
private int padding;

public void setResource(int ResourceId, int margin, int padding) {
this.resId = ResourceId;
this.margin = (int) (margin * scale + 0.5f);
this.padding = (int) (padding * scale + 0.5f);
}

public TextView getNewTextView() {

GridLayout.LayoutParams layoutParams = new GridLayout.LayoutParams();
layoutParams.width = getResources().getDisplayMetrics().widthPixels / 4 - 2 * margin;
layoutParams.height = GridLayout.LayoutParams.WRAP_CONTENT;
layoutParams.setMargins(margin, margin, margin, margin);

TextView tv = new TextView(getContext());
tv.setLayoutParams(layoutParams);
tv.setGravity(Gravity.CENTER);
tv.setBackgroundResource(resId);
tv.setPadding(padding, padding, padding, padding);

if (ableDrag) {
tv.setOnLongClickListener(olcl);
} else {
tv.setOnLongClickListener(null);
}

tv.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
if (itemClickListener != null) {
itemClickListener.onItemClick((TextView) view);
}
}
});
return tv;
}
}

drawable/selector_textbg.xml：

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_enabled="true" android:drawable="@drawable/shape_textbg_nomal"/>
<item android:state_enabled="false" android:drawable="@drawable/shape_textbg_pressed"/>

</selector>

drawable/shape_textbg_nomal.xml：

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<stroke android:width="1dp" android:color="@color/colorBlack"/>
<corners android:radius="@dimen/dp8"/>
<solid android:color="@color/colorWhite"/>
</shape>

drawable/shape_textbg_pressed.xml：

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<stroke android:width="1dp"
android:dashWidth="2dp"
android:dashGap="3dp"
android:color="@color/colorRed"/>
<corners android:radius="@dimen/dp8"/>
<solid android:color="@color/colorWhite"/>
</shape>