工作内容;

1.拖动控件

2.自定义可拖动的LinearLayout

学习分享：

一、拖动控件的实现步骤：

【前提：控件在RelativeLayout中，或者在GridLayout中】

1.按下图搞懂几个坐标

视图宽度 view.getWidth();

视图高度 view.getHeight()

橘色线：view.getLeft()

蓝色线：view.getRight()

红色线：view.getTop()

粉色线：view.getBottom()

上下左右的偏移都是相对于(0.0)来说的

.

2. MotionEvent类中 getRowX()和 getX()

1、event.getRowX()：触摸点相对于屏幕原点的x坐标

2、event.getX()：    触摸点相对于其所在组件原点的x坐标

3.实现控件拖动代码段：【仅用于view,不适合viewGroup】效果：view跟着手指走

//获取屏幕宽高，用于控制控件在屏幕内移动

DisplayMetrics dm = getResources().getDisplayMetrics();

screenWidth = dm.widthPixels;

screenHeight = dm.heightPixels - 100;//这里减去的100是下边的back键和menu键那一栏的高度，看情况而定

//核心代码段【OnTouchListener()的onTouch方法，控件去设置它就可以了】

@Override

public boolean onTouch(View v, MotionEvent event) {

int action = event.getAction();

switch (action) {

case MotionEvent.ACTION_DOWN:

lastX = (int) event.getRawX();//移动

LogTool.e("发生Touch事件x:y____"":""\nrawX:rawY____"

+event.getRawX()+":"+event.getRawY());

//event.getRawX()事件点距离屏幕左上角的距离

int dx = (int) event.getRawX() - lastX;

int dy = (int) event.getRawY() - lastY;

int left = v.getLeft() + dx;

int top = v.getTop() + dy;

int right = v.getRight() + dx;

int bottom = v.getBottom() + dy;

if (left < 0) { //最右边

right = screenWidth;

left = right - v.getWidth();

}

if (top < 0) { //最下边

bottom = screenHeight;

top = bottom - v.getHeight();

}

v.layout(left, top, right, bottom);//再次将滑动其实位置定位

lastY = (int) event.getRawY();

break;

case MotionEvent.ACTION_UP:

break;

}

return true;

}

二、自定义可拖动linearLayout【类似于上面的拖动控件的代码，就直接贴java代码了】

import android.content.Context;

import android.util.AttributeSet;

import android.util.DisplayMetrics;

import android.view.MotionEvent;

import android.widget.LinearLayout;

public class DragViewGroup extends LinearLayout {

private int lastX,lastY,screenWidth,screenHeight;

public DragViewGroup(Context context) {

this(context, null);

}

public DragViewGroup(Context context, AttributeSet attrs) {

this(context, attrs, 0);

}

public DragViewGroup(Context context, AttributeSet attrs, int defStyleAttr) {

super(context, attrs, defStyleAttr);

DisplayMetrics dm = getResources().getDisplayMetrics();

screenWidth = dm.widthPixels;

screenHeight = dm.heightPixels-50;//减去下边的高度

}

//定位

@Override

protected void onLayout(boolean changed, int l, int t, int r, int b) {

super.onLayout(changed, l, t, r, b);

//可以在这里确定这个viewGroup的：宽 = r-l.高 = b - t

}

//拦截touch事件

@Override

public boolean onInterceptTouchEvent(MotionEvent ev) {

// LogTool.e("onInterceptTouchEvent");

int action = ev.getAction();

switch (action){

case MotionEvent.ACTION_DOWN:

lastX = (int) ev.getRawX();//设定移动的初始位置相对位置

lastY = (int) ev.getRawY();

break;

case MotionEvent.ACTION_MOVE://移动

//event.getRawX()事件点距离屏幕左上角的距离

int dx = (int) ev.getRawX() - lastX;

int dy = (int) ev.getRawY() - lastY;

int left = this.getLeft() + dx;

int top = this.getTop() + dy;

int right = this.getRight() + dx;

int bottom = this.getBottom() + dy;

if (left < 0) { //最左边

left = 0;

right = left + this.getWidth();

}

if (right > screenWidth) { //最右边

right = screenWidth;

left = right - this.getWidth();

}

if (top < 0) { //最上边

top = 0;

bottom = top + this.getHeight();

}

if (bottom > screenHeight) {//最下边

bottom = screenHeight;

top = bottom - this.getHeight();

}

this.layout(left, top, right, bottom);//设置控件的新位置

// LogTool.e("position:" + left + ", " + top + ", " + right + ", " + bottom);

lastX = (int) ev.getRawX();//再次将滑动其实位置定位

lastY = (int) ev.getRawY();

break;

case MotionEvent.ACTION_UP:

break;

}

return super.onInterceptTouchEvent(ev);

}

}

布局代码；

xml version="1.0"encoding="utf-8"?>xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="wrap_content"android:layout_height="wrap_content"android:orientation="vertical"android:id="@+id/linear_save_share">android:layout_width="wrap_content"android:layout_height="wrap_content"android:padding="3dp"android:orientation="vertical"android:background="@drawable/shape_save_share_linear">android:layout_width="40dp"android:layout_height="40dp"android:background="@drawable/unsaved"android:id="@+id/iv_save_ss"/>android:layout_width="match_parent"android:layout_height="0.5dp"android:background="@color/white"/>android:layout_width="40dp"android:layout_height="40dp"android:background="@drawable/share"android:id="@+id/iv_share_ss"/> include代码：

layout="@layout/layout_save_share"android:layout_width="wrap_content"android:layout_height="wrap_content"android:layout_alignParentRight="true"android:layout_marginTop="60dp"/>