[android] 08_进度条ProgressBar

Android 4.0

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进度条ProgressBar

ProgressBar.setMax(100);//设置最大刻度

ProgressBar.setProgress(0);//设置进度条的当前刻度，如果进度条的最大刻度为100，当前刻度为50，进度条将进行到一半。

1、布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context=".MainActivity" >

<ProgressBar

android:id="@+id/pb"

style="?android:attr/progressBarStyleHorizontal"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_alignParentLeft="true"

android:layout_alignParentTop="true" />

<Button

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_below="@+id/pb"

android:layout_centerHorizontal="true"

android:onClick="click"

android:text="按下进度条走动" />

</RelativeLayout>

2、核心代码：

package cn.zengfansheng.progressbar;
 
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.ProgressBar;
 
public class MainActivity extends Activity {
 
    private ProgressBar pb;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        pb = (ProgressBar) this.findViewById(R.id.pb);
        pb.setMax(100);
        pb.setProgress(0);
 
    }
 
    public void click(View view) {
        new Thread() {// 如果不放在子线程里面，更新UI，要等到全部pb走完，ui才会更新
 
            @Override
            public void run() {
                super.run();
                for (int i = 1; i <= 100; i++) {
                    pb.setProgress(i);
                    try {
                        Thread.sleep(100);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
 
        }.start();
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

3、结果：

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