<ProgressBar style="?android:attr/progressBarStyleHorizontal"android:layout_width="match_parent"android:layout_height="wrap_content"android:progress="30"/>

private ProgressBar pb_progressBar1;pb_progressBar1=(ProgressBar) findViewById(R.id.pb_progressBar1);

if(progress<=100){　　progress=pb_progressBar1.getProgress();　　progress+=(int)(100*0.2);　　pb_progressBar1.setProgress(progress);}else progress=100;

package fry;import com.example.Ex26ProgressBar.R;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.ProgressBar;public class Activity01 extends Activity implements OnClickListener{  /*   * 進度條ProgressBar使用方法   * 1、在layout布局文件中創建ProgressBar控件   * 2、用ProgressBar對象指向ProgressBar控件   * 3、通過ProgressBar對象的getProgress()和setProgress()方法對進度進行修改   *    */  private Button btn_addProgress;  private Button btn_minusProgress;  private ProgressBar pb_progressBar1;  private int progress;  @Override  protected void onCreate(Bundle savedInstanceState) {        // TODO Auto-generated method stub    super.onCreate(savedInstanceState);    setContentView(R.layout.activity01);        btn_addProgress=(Button) findViewById(R.id.btn_addProgress);    btn_minusProgress=(Button) findViewById(R.id.btn_minusProgress);    pb_progressBar1=(ProgressBar) findViewById(R.id.pb_progressBar1);        btn_addProgress.setOnClickListener(this);    btn_minusProgress.setOnClickListener(this);      }  @Override  public void onClick(View v) {    // TODO Auto-generated method stub    switch (v.getId()) {    case R.id.btn_addProgress:      if(progress<=100){        progress=pb_progressBar1.getProgress();        progress+=(int)(100*0.2);        pb_progressBar1.setProgress(progress);      }else progress=100;            break;    case R.id.btn_minusProgress:      if(progress>=0){        progress=pb_progressBar1.getProgress();        progress-=(int)(100*0.2);        pb_progressBar1.setProgress(progress);      }else progress=0;      break;    default:      break;    }  }}

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical" >  <!-- style設置控件樣式 -->  <!-- 用？來引用東西 -->  <ProgressBar     style="?android:attr/progressBarStyleSmall"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    />    <ProgressBar     style="?android:attr/progressBarStyleLarge"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    />      <ProgressBar     style="?android:attr/progressBarStyleLargeInverse"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    />    <ProgressBar     style="?android:attr/progressBarStyleHorizontal"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:progress="30"    />    <ProgressBar     android:id="@+id/pb_progressBar1"    style="?android:attr/progressBarStyleHorizontal"    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:progress="50"    android:secondaryProgress="80"    android:layout_marginTop="30dp"    />    <LinearLayout       android:layout_width="match_parent"      android:layout_height="wrap_content"      android:orientation="horizontal"    >    <Button     android:id="@+id/btn_addProgress"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="增加進度"    android:layout_weight="1"    />    <Button     android:id="@+id/btn_minusProgress"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:text="減少進度"    android:layout_weight="1"    />      </LinearLayout>  </LinearLayout>

progress=pb_progressBar1.getProgress();progress+=(int)(100*0.2);pb_progressBar1.setProgress(progress);