本文为大家分享了类似微信朋友圈，点击+号图片，可以加图片功能，供大家参考，具体内容如下

xml:

xmlns:app="http://schemas.android.com/apk/res-auto"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:layout_marginTop="40dp"

android:orientation="vertical" >

android:id="@+id/photoview"

android:layout_width="match_parent"

android:layout_height="wrap_content"

app:ninephoto_hspace="10dp"

app:ninephoto_vspace="10dp"

app:rainbowbar_color="@android:color/holo_blue_bright" >

NinePhotoView.java

public class NinePhotoView extends ViewGroup {

public static final int MAX_PHOTO_NUMBER = 9;

private int[] constImageIds = { R.drawable.girl_0, R.drawable.girl_1,

R.drawable.girl_2, R.drawable.girl_3, R.drawable.girl_4,

R.drawable.girl_5, R.drawable.girl_6, R.drawable.girl_7,

R.drawable.girl_8 };

// horizontal space among children views

int hSpace = Utils.dpToPx(10, getResources());

// vertical space among children views

int vSpace = Utils.dpToPx(10, getResources());

// every child view width and height.

int childWidth = 0;

int childHeight = 0;

// store images res id

ArrayList mImageResArrayList = new ArrayList(9);

private View addPhotoView;

public NinePhotoView(Context context) {

super(context);

}

public NinePhotoView(Context context, AttributeSet attrs) {

this(context, attrs, 0);

}

public NinePhotoView(Context context, AttributeSet attrs, int defStyle) {

super(context, attrs, defStyle);

TypedArray t = context.obtainStyledAttributes(attrs,

R.styleable.NinePhotoView, 0, 0);

hSpace = t.getDimensionPixelSize(

R.styleable.NinePhotoView_ninephoto_hspace, hSpace);

vSpace = t.getDimensionPixelSize(

R.styleable.NinePhotoView_ninephoto_vspace, vSpace);

t.recycle();

addPhotoView = new View(context);

addView(addPhotoView);

mImageResArrayList.add(new integer());

}

Measure

@Override

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

int rw = MeasureSpec.getSize(widthMeasureSpec);

int rh = MeasureSpec.getSize(heightMeasureSpec);

childWidth = (rw - 2 * hSpace) / 3;

childHeight = childWidth;

int childCount = this.getChildCount();

for (int i = 0; i < childCount; i++) {

View child = this.getChildAt(i);

//this.measureChild(child, widthMeasureSpec, heightMeasureSpec);

LayoutParams lParams = (LayoutParams) child.getLayoutParams();

lParams.left = (i % 3) * (childWidth + hSpace);

lParams.top = (i / 3) * (childWidth + vSpace);

}

int vw = rw;

int vh = rh;

if (childCount < 3) {

vw = childCount * (childWidth + hSpace);

}

vh = ((childCount + 3) / 3) * (childWidth + vSpace);

setMeasuredDimension(vw, vh);

}

我们的子View三个一排，而且都是正方形，所以我们上面通过循环很好去得到所有子View的位置，注意我们上面把子View的左上角坐标存储到我们自定义的LayoutParams 的left和top二个字段中，Layout阶段会使用，最后我们算得整个ViewGroup的宽高，调用setMeasuredDimension设置。

Layout

@Override

protected void onLayout(boolean arg0, int arg1, int arg2, int arg3, int arg4) {

int childCount = this.getChildCount();

for (int i = 0; i < childCount; i++) {

View child = this.getChildAt(i);

LayoutParams lParams = (LayoutParams) child.getLayoutParams();

child.layout(lParams.left, lParams.top, lParams.left + childWidth,

lParams.top + childHeight);

if (i == mImageResArrayList.size() - 1 && mImageResArrayList.size() != MAX_PHOTO_NUMBER) {

child.setBackgroundResource(R.drawable.add_photo);

child.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View arg0) {

addPhotoBtnClick();

}

});

}else {

child.setBackgroundResource(constImageIds[i]);

child.setOnClickListener(null);

}

}

}

public void addPhoto() {

if (mImageResArrayList.size() < MAX_PHOTO_NUMBER) {

View newChild = new View(getContext());

addView(newChild);

mImageResArrayList.add(new integer());

requestLayout();

invalidate();

}

}

public void addPhotoBtnClick() {

final CharSequence[] items = { "Take Photo", "Photo from gallery" };

AlertDialog.Builder builder = new AlertDialog.Builder(getContext());

builder.setItems(items, new DialogInterface.OnClickListener() {

@Override

public void onClick(DialogInterface arg0, int arg1) {

addPhoto();

}

});

builder.show();

}

最核心的就是调用layout方法，根据我们measure阶段获得的LayoutParams中的left和top字段，也很好对每个子View进行位置排列。然后判断在图片未达到最大值9张时，默认最后一张是+号图片，然后设置点击事件，弹出对话框供用户选择操作。

Draw

不需要重写，使用ViewGroup默认实现即可。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持找一找教程网。