Question

    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.initial_layout);

    // progress bar
    pb = (ProgressBar) findViewById(R.id.progressBar);
    pb.setVisibility(View.VISIBLE);
    new Thread(new Runnable() {
        @Override
        public void run() {
            while (progressStatus < 100) {
                progressStatus += 1;
                pbHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        pb.setProgress(progressStatus);
                    }
                });
                try {
                    Thread.sleep(70);
                }catch (Exception e) {
                    e.printStackTrace();
                }
            }
            if (pb.getProgress() >= 95) {
                Intent i1 = new Intent(initialActivity.this,startingActivity.class);
                startActivity(i1);
            }
        }
    }).start();
}

我的目标是在进度条完成加载时自动加载下一个活动，而不会触发任何其他事件，但我似乎无法做到这一点。我觉得线程有些不对劲，我是个傻瓜。任何帮助表示赞赏。

Answer 1

You have to start the activity from the main thread. Consider executing the runnable from a handler. ` Handler handler = new Handler(); 
            handler.postDelayed(new Runnable() {
        @Override
        public void run() {
            while (progressStatus < 100) {
                progressStatus += 1;
                pbHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        pb.setProgress(progressStatus);
                    }
                });
                try {
                    Thread.sleep(70);
                }catch (Exception e) {
                    e.printStackTrace();
                }
            }
            if (pb.getProgress() >= 95) {
                Intent i1 = new Intent(initialActivity.this,startingActivity.class);
                startActivity(i1);
            }
        }
    },1000);
return;`

Answer 2

if (pb.getProgress() >= 95) {
                Intent i1 = new Intent(initialActivity.this,startingActivity.class);
                startActivity(i1);
            }

上面的代码不正确

if (pb.getProgress() >= 95) {
                Intent i1 = new Intent(context,startingActivity.class);
                startActivity(i1);
            }

将上下文存储在活动成员变量中的当前活动中;

 public Context context = getApplicationContext();

更好的解决方案是使用AsynTask

示例

http://programmerguru.com/android-tutorial/android-asynctask-example/

Answer 3

定义自定义界面，让您在完成进度时回调：

public interface OnProgressFinishListener{
    public void onProgressFinish();
}

使用AsyncTask更新进度：

public void startProgress(final OnProgressFinishListener onProgressFinishListener){
    new AsyncTask<Void,Integer,Integer>(){
      @Override
      protected Integer doInBackground(Void... params) {
          while (progressStatus < 100) {
                 progressStatus += 1;
                 publishProgress(progressStatus);

                 try {
                      Thread.sleep(70);
                 }catch (Exception e) {
                      e.printStackTrace();
                 }
          }
          return progressStatus;
      }

      @Override
      protected void onProgressUpdate(Integer... values) {
         super.onProgressUpdate(values);
         pb.setProgress(values[0]);
      }

      @Override
      protected void onPostExecute(Integer progress) {
         super.onPostExecute(progress);
         if(progress==100){
            onProgressFinishListener.onProgressFinish();
         }
      }
   }.execute();
}

如何实现自定义界面：

pb = (ProgressBar) findViewById(R.id.progressBar);
pb.setVisibility(View.VISIBLE);
startProgress(new OnProgressFinishListener() {
    @Override
    public void onProgressFinish() {
        pb.setVisibility(View.GONE);
        Toast.makeText(MainActivity.this,"Progress Finish",Toast.LENGTH_SHORT).show();
    }
 });

问题加载下一个活动

3 个答案: