Android 自定义Dialog 实例

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：

 Dialog中Style代码：

 背景dialog_bg 代码：

 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。