使用ProgressBar实现加载进度条

一、ProgressBar简介

ProgressBar是进度条组件，通常用于向用户展示某个耗时操作完成的进度，而不让用户感觉是程序失去了相应，从而更好地提升用户界面的友好性

二、指定ProgressBar显示风格

1、水平进度条：可以精确显示进度（可以显示刻度或者百分比）

2、环形进度条：不可以精确显示进度（一直转，类似过场动画）

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Window;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //启用窗口特征，启用带进度和不带进度条
        requestWindowFeature(Window.FEATURE_PROGRESS);//带
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);//不带
        setContentView(R.layout.activity_main);
        //显示两种进度条
        setProgressBarVisibility(true);
        setProgressBarIndeterminateVisibility(true);
        setProgress(600);
    }
}

三、关键属性和方法

四、使用ProgressBar实现进度条

（@string快捷键：alt+enter）

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;

public class MainActivity extends Activity implements View.OnClickListener{

    private ProgressBar progress;
    private Button add;
    private Button reduce;
    private Button reset;
    private TextView textView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //启用窗口特征，启用带进度和不带进度条
        requestWindowFeature(Window.FEATURE_PROGRESS);//带
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);//不带
        setContentView(R.layout.main);
        //显示两种进度条
        setProgressBarVisibility(true);
        setProgressBarIndeterminateVisibility(true);
        setProgress(600);
        init();
    }

    private void init() {
        progress = (ProgressBar) findViewById(R.id.horiz);
        add = (Button) findViewById(R.id.add);
        reduce = (Button) findViewById(R.id.reduce);
        reset = (Button) findViewById(R.id.reset);
        textView = (TextView) findViewById(R.id.text);
        //getPrgress()获取第一进度条的进度
        int first =  progress.getProgress();
        //获取第二进度条的进度
        int second = progress.getSecondaryProgress();
        //获取进度条的最大进度
        int max = progress.getMax();
        textView.setText("第一进度百分比"+(int)(first/(float)max*100)+"% 第二进度的百分比"+(int)(second/(float)max*100)+"%");
        add.setOnClickListener(this);
        reduce.setOnClickListener(this);
        reset.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId())
        {
            case R.id.add:
            {
                //增加第一进度和第二进度10个刻度
                progress.incrementProgressBy(10);
                progress.incrementSecondaryProgressBy(10);
                break;
            }
            case R.id.reduce:
            {
                //减少第一进度和第二进度10个刻度
                progress.incrementProgressBy(-10);
                progress.incrementSecondaryProgressBy(-10);
                break;
            }
            case R.id.reset:
            {
                progress.setProgress(50);
                progress.setSecondaryProgress(80);
                break;
            }
        }textView.setText("第一进度百分比"+(int)(progress.getProgress()/(float)progress.getMax()*100)+"% 第二进度的百分比"+(int)(progress.getSecondaryProgress()/(float)progress.getMax()*100)+"%");
    }
}

五、对话框形式进度条

         case  R.id.show:
            {
                //新建ProgressDialog对象
                prodialog = new ProgressDialog(MainActivity.this);
                //设置显示风格
                prodialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
                //设置标题
                prodialog.setTitle("找男友呀");
                //设置对话框里的文字信息
                prodialog.setMessage("找呀找呀找朋友");
                //设置图标
                prodialog.setIcon(R.drawable.gun);
                /**
                 * 设定关于ProgressBar的一些属性
                 */
                //设定最大进度
                prodialog.setMax(100);
                //设定初始化已经增长的进度
                prodialog.incrementProgressBy(50);
                //进度条是明确显示进度的
                prodialog.setIndeterminate(false);
                /**
                 *设定一个确定按钮
                 **/
            prodialog.setButton(DialogInterface.BUTTON_POSITIVE,"确定", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    Toast.makeText(MainActivity.this,"hahaah",Toast.LENGTH_SHORT).show();
                }
            });
                //是否可以通过返回按钮退出对话框
                prodialog.setCancelable(true);
                //显示ProgressDialog
                prodialog.show();
                break;
            }

六、自定义ProgressBar样式

      android:progressDrawable="@drawable/progress_bar"

1、自定义progress_bar样式

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

    <item android:id="@android:id/background">
        <shape>
            <corners android:radius="5dip" />

        <solid android:color="#88000000"/>
        </shape>
    </item>
    <item android:id="@android:id/secondaryProgress">
        <clip>
            <shape>
                <corners android:radius="5dip" />

                <gradient
                    android:angle="270"
                    android:centerColor="#C6B7FF"
                    android:centerY="0.75"
                    android:endColor="#C3B2FF"
                    android:startColor="#B9A4FF" />
            </shape>
        </clip>
    </item>
    <item android:id="@android:id/progress">
        <clip>
            <shape>
                <corners android:radius="5dip" />

            <gradient
                android:angle="270"
                android:centerColor="#74EBFF"
                android:centerY="0.75"
                android:endColor="#8EEFFF"
                android:startColor="#57E8FF" />
            </shape>
        </clip>
    </item>

</layer-list>