开发中经常需要请求网络获取数据，我们在请求网络到得到数据时当中需要等待一些时间，为了增加用户体验，我们一般会用一个Dialog来提示用户我们在加载网络数据。
今天我们来实现如下效果的加载中Dialog。
从图中我们可以看到要这个Dialog是图片还有文字组成的，(不过我这里使用代码实现的，没有用图片)，以下是这个加载图形的代码：
public class LVCircularRing extends View {
private float mWidth = 0f;
private float mPadding = 0f;
private float startAngle = 0f;
private Paint mPaint;
public LVCircularRing(Context context) {
this(context, null);
}
public LVCircularRing(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public LVCircularRing(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initPaint();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (getMeasuredWidth() > getHeight())
mWidth = getMeasuredHeight();
else
mWidth = getMeasuredWidth();
mPadding = 5;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
mPaint.setColor(Color.argb(100, 255, 255, 255));
canvas.drawCircle(mWidth / 2, mWidth / 2, mWidth / 2 - mPadding, mPaint);
mPaint.setColor(Color.WHITE);
RectF rectF = new RectF(mPadding, mPadding, mWidth - mPadding, mWidth - mPadding);
canvas.drawArc(rectF, startAngle, 100
, false, mPaint);//第四个参数是否显示半径
}
private void initPaint() {
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setColor(Color.WHITE);
mPaint.setStrokeWidth(8);
}
public void startAnim() {
stopAnim();
startViewAnim(0f, 1f, 1000);
}
public void stopAnim() {
if (valueAnimator != null) {
clearAnimation();
valueAnimator.setRepeatCount(1);
valueAnimator.cancel();
valueAnimator.end();
}
}
ValueAnimator valueAnimator;
private ValueAnimator startViewAnim(float startF, final float endF, long time) {
valueAnimator = ValueAnimator.ofFloat(startF, endF);
valueAnimator.setDuration(time);
valueAnimator.setInterpolator(new LinearInterpolator());
valueAnimator.setRepeatCount(ValueAnimator.INFINITE);//无限循环
valueAnimator.setRepeatMode(ValueAnimator.RESTART);//
valueAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
float value = (float) valueAnimator.getAnimatedValue();
startAngle = 360 * value;
invalidate();
}
});
valueAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
}
});
if (!valueAnimator.isRunning()) {
valueAnimator.start();
}
return valueAnimator;
}
}
Dialog 代码：
public class LoadingDialog {
LVCircularRing mLoadingView;
Dialog mLoadingDialog;
public LoadingDialog(Context context,String msg) {
// 首先得到整个View
View view = LayoutInflater.from(context).inflate(
R.layout.loading_dialog_view, null);
// 获取整个布局
LinearLayout layout = (LinearLayout) view.findViewById(R.id.dialog_view);
// 页面中的LoadingView
mLoadingView = (LVCircularRing) view.findViewById(R.id.lv_circularring);
// 页面中显示文本
TextView loadingText = (TextView) view.findViewById(R.id.loading_text);
// 显示文本
loadingText.setText(msg);
// 创建自定义样式的Dialog
mLoadingDialog = new Dialog(context, R.style.loading_dialog);
// 设置返回键无效
mLoadingDialog.setCancelable(false);
mLoadingDialog.setContentView(layout, new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT));
}
public void show(){
mLoadingDialog.show();
mLoadingView.startAnim();
}
public void close(){
if (mLoadingDialog!=null) {
mLoadingView.stopAnim();
mLoadingDialog.dismiss();
mLoadingDialog=null;
}
}
}
布局文件loading_dialog_view 代码：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/dialog_view" android:layout_width="match_parent" android:layout_height="match_parent" android:gravity="center" android:background="@drawable/dialog_bg" android:padding="20dp" android:orientation="vertical"> <com.ye.daqiapp.ui.widget.loading.LVCircularRing android:id="@+id/lv_circularring" android:layout_width="50dp" android:layout_height="50dp"/> <TextView android:id="@+id/loading_text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textColor="#ffffff" android:layout_marginTop="5dp" android:textSize="15sp"/> </LinearLayout>
Dialog中Style代码：
<style name="loading_dialog" parent="android:style/Theme.Dialog"> <item name="android:windowFrame">@null</item> <item name="android:windowNoTitle">true</item> <item name="android:windowBackground">@android:color/transparent</item> <item name="android:windowIsFloating">true</item> <item name="android:backgroundDimEnabled">false</item> <item name="android:windowContentOverlay">@null</item> </style>
背景dialog_bg 代码：
<?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android"> <!-- 内部颜色 --> <solid android:color="#444444" /> <!-- 圆角的幅度 --> <corners android:bottomLeftRadius="3dp" android:bottomRightRadius="3dp" android:topLeftRadius="3dp" android:topRightRadius="3dp" /> </shape>
如何使用：在需要使用的地方初始化Dialog:
LoadingDialog dialog=new LoadingDialog(context,"玩命加载中..."); //显示Dialog dialog.show(); //关闭Dialog dialog.close();
以上是对Android Dialog 重写的小示例，有需要的朋友可以参考下。