本文為大家分享了類似微信朋友圈,點擊+號圖片,可以加圖片功能,供大家參考,具體內容如下

xml:
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"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" > <com.sw.demo.widget.NinePhotoView 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" > </com.sw.demo.widget.NinePhotoView>
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 viewsint hSpace = Utils.dpToPx(10, getResources());// vertical space among children viewsint vSpace = Utils.dpToPx(10, getResources()); // every child view width and height.int childWidth = 0;int childHeight = 0; // store images res idArrayList<integer> mImageResArrayList = new ArrayList<integer>(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
@Overrideprotected 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);}我們的子View三個一排,而且都是正方形,所以我們上面通過循環很好去得到所有子View的位置,注意我們上面把子View的左上角坐標存儲到我們自定義的LayoutParams 的left和top二個字段中,Layout階段會使用,最后我們算得整個ViewGroup的寬高,調用setMeasuredDimension設置。
Layout
@Overrideprotected 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();}最核心的就是調用layout方法,根據我們measure階段獲得的LayoutParams中的left和top字段,也很好對每個子View進行位置排列。然后判斷在圖片未達到最大值9張時,默認最后一張是+號圖片,然后設置點擊事件,彈出對話框供用戶選擇操作。
Draw
不需要重寫,使用ViewGroup默認實現即可。

以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支持武林網。
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