Android自定义等待对话框

最近，看了好多的APP的等待对话框，发现自己的太lower，于是就研究了一番，最后经过苦心努力，实现一个。

• 自定义一个LoadingIndicatorView(extends View )类
• 编写values/attrs.xml，在其中编写styleable和item等标签元素
• 在布局文件中LoadingIndicatorView使用自定义的属性（注意namespace）
• 在LoadingIndicatorView的构造方法中通过TypedArray获取
  

描述就提供这些，一下是代码的展示，非常的详细。
1、自定义属性的声明文件

<declare-styleable name="AVLoadingIndicatorView">
    <attr name="indicator">
      <flag name="BallSpinFadeLoader" value="22"/>
    </attr>
    <attr name="indicator_color" format="color"/>
  </declare-styleable> 

<pre name="code" class="html">

LoadingIndicatorView.java

import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Build;
import android.support.annotation.IntDef;
import android.util.AttributeSet;
import android.view.View; 

import com.chni.lidong.androidtestdemo.R; 

/**
 * Created by lidongon 2016/1/31
 *
 .BallSpinFadeLoader,
 *
 */
public class LoadingIndicatorView extends View { 

  //indicators 指示器
  public static final int BallSpinFadeLoader=22; 

  @IntDef(flag = true,
      value = {
          BallSpinFadeLoader,
      })
  public @interface Indicator{} 

  //Sizes (with defaults in DP)
  public static final int DEFAULT_SIZE=45; 

  //attrs
  int mIndicatorId;
  int mIndicatorColor; 

  Paint mPaint; 

  BaseIndicatorController mIndicatorController; 

  private boolean mHasAnimation; 

  public LoadingIndicatorView(Context context) {
    super(context);
    init(null, 0);
  } 

  public LoadingIndicatorView(Context context, AttributeSet attrs) {
    super(context, attrs);
    init(attrs, 0);
  } 

  public LoadingIndicatorView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    init(attrs, defStyleAttr);
  } 

  @TargetApi(Build.VERSION_CODES.LOLLIPOP)
  public LoadingIndicatorView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
    super(context, attrs, defStyleAttr, defStyleRes);
    init(attrs, defStyleAttr);
  } 

  private void init(AttributeSet attrs, int defStyle) {
    /**
     *获取TypedArray(属性的集合)
     */
    TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.AVLoadingIndicatorView);
    mIndicatorId=a.getInt(R.styleable.AVLoadingIndicatorView_indicator, BallSpinFadeLoader);//获取编号属性
    mIndicatorColor=a.getColor(R.styleable.AVLoadingIndicatorView_indicator_color, Color.WHITE);//获取颜色属性
    a.recycle();//回收属性的集合
    mPaint=new Paint();
    mPaint.setColor(mIndicatorColor);//设置画笔的颜色
    mPaint.setStyle(Paint.Style.FILL);//设置画笔的样式为填充
    mPaint.setAntiAlias(true);//去锯齿
    applyIndicator();//
  } 

  private void applyIndicator(){
    switch (mIndicatorId){
      case BallSpinFadeLoader:
        mIndicatorController=new BallSpinFadeLoaderIndicator();
        break;
    }
    mIndicatorController.setTarget(this);//将控件设置到当前View
  } 

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    int width = measureDimension(dp2px(DEFAULT_SIZE), widthMeasureSpec);//获取View的宽度
    int height = measureDimension(dp2px(DEFAULT_SIZE), heightMeasureSpec);//获取View的高度
    setMeasuredDimension(width, height);//
  } 

  /**
   *测量的 维度
   * @param defaultSize 默认大小
   * @param measureSpec {@see widthMeasureSpec,heightMeasureSpec}
   * @return 返回测量的结果
   */
  private int measureDimension(int defaultSize,int measureSpec){
    int result = defaultSize;
    int specMode = MeasureSpec.getMode(measureSpec);//测量规范
    int specSize = MeasureSpec.getSize(measureSpec);//测量大小
    if (specMode == MeasureSpec.EXACTLY) {//父控件已经为子控件设置确定的大小，子控件会考虑父控件给他的大小，自己需要多大设置多大
      result = specSize;
    } else if (specMode == MeasureSpec.AT_MOST) {//子控件可以设置自己希望的指定大小
      result = Math.min(defaultSize, specSize);//取最小值
    } else {
      result = defaultSize;
    }
    return result;
  } 

  @Override
  protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    drawIndicator(canvas);
  } 

  @Override
  protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
    super.onLayout(changed, left, top, right, bottom);
    if (!mHasAnimation){
      mHasAnimation=true;
      applyAnimation();
    }
  } 

  void drawIndicator(Canvas canvas){
    mIndicatorController.draw(canvas,mPaint);
  } 

  void applyAnimation(){
    mIndicatorController.createAnimation();
  } 

  private int dp2px(int dpValue) {
    return (int) getContext().getResources().getDisplayMetrics().density * dpValue;
  }

BaseIndicatorController.java

package com.chni.lidong.androidtestdemo.loading; 

import android.graphics.Canvas;
import android.graphics.Paint;
import android.view.View; 

/**
 * Created by lidongon 2016/1/31
 */
public abstract class BaseIndicatorController { 

  private View mTarget; 

  public void setTarget(View target){
    this.mTarget=target;
  } 

  public View getTarget(){
    return mTarget;
  } 

  /**
   * 得到View的宽度
   * @return
   */
  public int getWidth(){
    return mTarget.getWidth();
  } 

  /**
   * 得到view的高度
   * @return
   */
  public int getHeight(){
    return mTarget.getHeight();
  } 

  /**
   * 刷新view
   */
  public void postInvalidate(){
    mTarget.postInvalidate();
  } 

  /**
   * draw indicator what ever
   * you want to draw
   * 绘制indicate
   * @param canvas
   * @param paint
   */
  public abstract void draw(Canvas canvas,Paint paint); 

  /**
   * create animation or animations
   * ,and add to your indicator.
   * 创建动画或者动画集合，添加到indcator
   */
  public abstract void createAnimation(); 

}

BallSpinFadeLoaderIndicator.java

package com.chni.lidong.androidtestdemo.loading; 

import android.graphics.Canvas;
import android.graphics.Paint; 

import com.nineoldandroids.animation.ValueAnimator; 

/**
 * Created by lidongon 2016/1/31
 */
public class BallSpinFadeLoaderIndicator extends BaseIndicatorController { 

  public static final float SCALE=1.0f; 

  public static final int ALPHA=255;
  /**
   * 圆点的比例
   */
  float[] scaleFloats=new float[]{SCALE,
      SCALE,
      SCALE,
      SCALE,
      SCALE,
      SCALE,
      SCALE,
      SCALE};
  /**
   * 圆点的透明度集合
   */
  int[] alphas=new int[]{ALPHA,
      ALPHA,
      ALPHA,
      ALPHA,
      ALPHA,
      ALPHA,
      ALPHA,
      ALPHA}; 

  @Override
  public void draw(Canvas canvas, Paint paint) {
    float radius=getWidth()/10;
    for (int i = 0; i < 8; i++) {
      canvas.save();
      Point point=circleAt(getWidth(),getHeight(),getWidth()/2-radius,i*(Math.PI/4));
      canvas.translate(point.x,point.y);
      canvas.scale(scaleFloats[i],scaleFloats[i]);
      paint.setAlpha(alphas[i]);
      canvas.drawCircle(0,0,radius,paint);
      canvas.restore();
    }
  } 

  /**
   * 圆O的圆心为(a,b),半径为R,点A与到X轴的为角α.
   *则点A的坐标为(a+R*cosα,b+R*sinα)
   * @param width
   * @param height
   * @param radius
   * @param angle
   * @return
   */
  Point circleAt(int width,int height,float radius,double angle){
    float x= (float) (width/2+radius*(Math.cos(angle)));
    float y= (float) (height/2+radius*(Math.sin(angle)));
    return new Point(x,y);
  } 

  @Override
  public void createAnimation() {
    int[] delays= {0, 120, 240, 360, 480, 600, 720, 780, 840};
    for (int i = 0; i < 8; i++) {
      final int index=i;
      ValueAnimator scaleAnim=ValueAnimator.ofFloat(1,0.4f,1);//创建ValueAnimator对象
      scaleAnim.setDuration(1000);//设置动画的持续时间
      scaleAnim.setRepeatCount(-1);//设置动画是否重复
      scaleAnim.setStartDelay(delays[i]);//延迟启动动画
      scaleAnim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {//ValueAnimator只负责第一次的内容，因此必须通过监听来实现对象的相关属性的更新
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
          scaleFloats[index] = (float) animation.getAnimatedValue();//获取当前帧的值
          postInvalidate();
        }
      });
      scaleAnim.start();//启动属性动画 

      ValueAnimator alphaAnim=ValueAnimator.ofInt(255, 77, 255);//透明度动画
      alphaAnim.setDuration(1000);//
      alphaAnim.setRepeatCount(-1);
      alphaAnim.setStartDelay(delays[i]);
      alphaAnim.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
        @Override
        public void onAnimationUpdate(ValueAnimator animation) {
          alphas[index] = (int) animation.getAnimatedValue();
          postInvalidate();
        }
      });
      alphaAnim.start();
    }
  } 

  final class Point{
    public float x;
    public float y; 

    public Point(float x, float y){
      this.x=x;
      this.y=y;
    }
  } 

}

UIHelp.java

package com.chni.lidong.androidtestdemo.utils; 

import android.app.Activity;
import android.app.Dialog;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView; 

import com.chni.lidong.androidtestdemo.R; 

/**
 * 对话框的实现
 * @author 李东
 * @Date 2014-11-23
 */
public class UIHelper { 

  /** 加载数据对话框 */
  private static Dialog mLoadingDialog; 

  /**
   * 显示加载对话框
   * @param context 上下文
   * @param msg 对话框显示内容
   * @param cancelable 对话框是否可以取消
   */
  public static void showDialogForLoading(Activity context, String msg, boolean cancelable) {
    View view = LayoutInflater.from(context).inflate(R.layout.layout_loading_dialog, null);
    TextView loadingText = (TextView)view.findViewById(R.id.id_tv_loading_dialog_text);
    loadingText.setText(msg); 

    mLoadingDialog = new Dialog(context, R.style.loading_dialog_style);
    mLoadingDialog.setCancelable(cancelable);
    mLoadingDialog.setContentView(view, new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT));
    mLoadingDialog.show();
  } 

  /**
   * 关闭加载对话框
   */
  public static void hideDialogForLoading() {
    if(mLoadingDialog != null && mLoadingDialog.isShowing()) {
      mLoadingDialog.cancel();
    }
  } 

}

对话框的布局：

<?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="wrap_content"
  android:layout_height="wrap_content"
  android:background="@drawable/bg_loading_dialog_shape"
  android:gravity="center"
  android:minHeight="60dp"
  android:minWidth="180dp"
  android:orientation="vertical"
  android:padding="@dimen/padding_10" >

  <LinearLayout
    android:layout_width="wrap_content"
    android:layout_weight="1"
    android:gravity="center"
    android:layout_height="wrap_content">

    <com.chni.lidong.androidtestdemo.loading.AVLoadingIndicatorView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      app:indicator="BallSpinFadeLoader"
      app:indicator_color="@color/green"
      />

  </LinearLayout>

  <TextView
    android:id="@+id/id_tv_loading_dialog_text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="@dimen/padding_5"
    android:text="正在登录…"
    android:textColor="@color/content"
    android:textSize="14sp" />

</LinearLayout>

对话框的样式：

<!-- 自定义Loading Dialog -->
<style name="loading_dialog_style" parent="@android:style/Theme.Dialog">
  <item name="android:windowFrame">@null</item>
  <item name="android:windowNoTitle">true</item>
  <item name="android:windowBackground">@color/transparent</item>
  <item name="android:windowIsFloating">true</item>
  <item name="android:windowContentOverlay">@null</item>
</style>

MainActivity.java

public class Main7Activity extends AppCompatActivity { 

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main7);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar); 

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
            .setAction("Action", null).show();
      }
    });
    UIHelper.showDialogForLoading(this, "正在加载...", true);
    Handler handler = new Handler();
    handler.postDelayed(new Runnable() {
      @Override
      public void run() {
        UIHelper.hideDialogForLoading();
      }
    },10000);
  } 

} 

效果图;

以上就是本文的全部内容，希望对大家的学习有所帮助。