android的Progressbar怎么用
1、在android中，Progressbar可以用来提醒用户某个任务的进度。下面我们来模拟一个下载进度来看一下。
2、首先我们创建一个按钮来启动一个带有progressbar的提醒。
3、编写代码为按钮添加一个点击事件。
4、运行效果。
5、修改progressbar的风格。
6、完整的代码。
public void onClick(View v) {
// prepare for a progress bar dialog
progressBar = new ProgressDialog(v.getContext());
progressBar.setCancelable(true);
progressBar.setMessage("File downloading ...");
progressBar.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progressBar.setProgress(0);
progressBar.setMax(100);
progressBar.show();
//reset progress bar status
progressBarStatus = 0;
//reset filesize
fileSize = 0;
new Thread(new Runnable() {
public void run() {
while (progressBarStatus < 100) {
// process some tasks
progressBarStatus = doSomeTasks();
// your computer is too fast, sleep 1 second
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
// Update the progress bar
progressBarHandler.post(new Runnable() {
public void run() {
progressBar.setProgress(progressBarStatus);
}
});
}
// ok, file is downloaded,
if (progressBarStatus >= 100) {
// sleep 2 seconds, so that you can see the 100%
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
// close the progress bar dialog
progressBar.dismiss();
}
}
}).start();
}
});
}
// file download simulator... a really simple
public int doSomeTasks() {
while (fileSize <= 1000000) {
fileSize++;
if (fileSize == 100000) {
return 10;
} else if (fileSize == 200000) {
return 20;
} else if (fileSize == 300000) {
return 30;
}
// ...add your own
}
return 100;
}